Dissertations / Theses: 'Structural New Zealand'

1

Pomeroy, A. "A sociological analysis of structural change in pastoral farming in New Zealand." Thesis, University of Essex, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374723.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Down, Taylor Nicholson. "Structural-stratigraphic reconstruction of the lower Whakataki formation, north island, New Zealand." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/94176/1/Taylor_Down_Thesis.pdf.

Full text

Abstract:

This thesis details a Miocene aged sedimentary rock formation located in north island New Zealand. Mapping, stratigraphic logging and petrographic analysis of the rock formation ascertained that it was deposited in a deep-marine, tectonically active region. The work details the make-up of the sedimentary rocks using geochemistry and microscopy to define their origin. This definition was used to interpret the depositional model of the sediments detailing how they were transported and how they were emplaced.

APA, Harvard, Vancouver, ISO, and other styles

3

Blatchford, Hannah Jane. "The Structural Evolution Of A Portion Of The Median Batholith And Its Host Rock In Central Fiordland, New Zealand: Examples Of Partitioned Transpression And Structural Reactivation." ScholarWorks @ UVM, 2016. https://scholarworks.uvm.edu/graddis/635.

Full text

Abstract:

This thesis presents the results of structural analyses and detailed field mapping from a region near Adams Burn in central Fiordland, New Zealand. The region preserves assemblages of metasedimentary and metaigneous rocks deposited, intruded, and ultimately metamorphosed and deformed during the growth of a Gondwana-margin continental arc from Cambrian-Early Cretaceous. Evidence of arc growth is preserved in the Late Devonian-Early Cretaceous Median Batholith, a belt of intrusive rock whose growth culminated with the emplacement of the Western Fiordland Orthogneiss (WFO) into the middle-lower crust of the margin. Following this magmatic flare-up, the margin experienced Late Cretaceous extensional orogenic collapse and rifting. During the Late Tertiary, the margin records oblique convergence that preceded the Alpine fault. The history of arc growth and record of changing tectonic and deformational regimes makes the area ideal for study of structural reactivation during multiple cycles of magmatism, metamorphism and deformation, including during a mid-lower crust magma flare-up. Structural and lithologic mapping, structural analyses, and cross-cutting relationships between superposed structures and three intrusions were used to bracket the relative timing of four tectonic events (D1-D4), spanning the Paleozoic to the Tertiary. The oldest event (D1) created a composite fabric in the metasedimentary and metaigneous rocks of the Irene Complex and Jaquiery granitoid gneiss prior to emplacement of the Carboniferous Cozette pluton. S1 foliation development, set the stage for structural reactivation during the second phase of deformation (D2), where S1 was folded and reactivated via intra-arc shearing. These second-phase structures were coeval with the emplacement of the Misty pluton, (part of WFO in central Fiordland), and record crustal thickening and deformation involving a kinematically partitioned style of transpression. Arc-normal displacements were localized into the rocks of the Irene Complex. Oblique displacements were localized along the Misty-Cozette plutonic contact, forming a ≥1 km-wide, upper amphibolite-facies gneissic shear zone that records sinistral-reverse offset. Second-phase structures are cross-cut by widespread leucocratic pegmatite dikes. S2 in the Cozette and Misty plutons is reactivated by localized, ≤10 m-thick, greenschist-facies (ultra)mylonitic shear zones that record sinistral-normal offsets. S3/L3 shear zones and lithologic contacts were then reactivated by two episodes of Tertiary, fourth-phase faulting compatible with Alpine faulting, everywhere truncating the pegmatite dikes. Early faults accommodated shortening normal to the Alpine fault, and were obliquely reactivated by a younger population of faults during dextral transpression. My results show that structural reactivation occurred repeatedly after D1, and that structural inheritance played a key role in the geometry, distribution, and kinematics of younger deformation events throughout the arc's history. The sheeted emplacement of the Misty pluton was accompanied, and possibly facilitated, by a system of partitioned transpression during Early Cretaceous crustal thickening and arc magmatism. These results show that transpression helped accommodate and move magma through the middle and lower crust during the flare-up. This conclusion is important for the study of continental arcs globally, as evidence of deformation during high-flux magmatism at lower crustal depths (~40 km) is rarely preserved and exhumed to the surface.

APA, Harvard, Vancouver, ISO, and other styles

4

Scott, John G., and n/a. "Structural controls on gold - quartz vein mineralisation in the Otago schist, New Zealand." University of Otago. Department of Geology, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070412.160816.

Full text

Abstract:

Hydrothermal fluid flow is spatially and genetically associated with deformation in the earth�s crust. In the Otago Schist, New Zealand, the circulation of hydrothermal fluids in the Cretaceous formed numerous mesothermal gold-quartz vein deposits. Otago schist rocks are largely L-S tectonites in which the penetrative fabric is the product of more than one deformation phase/transposition cycle. Regional correlation of deformation events allowed mineralised deposits to be related to the structural evolution of the Otago Schist. Compilation of a detailed tectonostratigraphy of New Zealand basement rocks reveals that extensional mineralisation correlates with the onset of localised terrestrial fanglomerate deposition, thermal perturbation and granitic intrusion that mark the beginning of New Zealand rifting from the Antarctic portion of Gondwana. Laminated and breccia textures in mineralised veins suggest that host structures have experienced repeated episodes of incremental slip and hydrothermal fluid flow. However, analysis of vein orientation data in terms of fault reactivation theory (Amontons Law) shows that most deposits contain veins that are unfavourably oriented for frictional reactivation. Repeated movement on unfavourably oriented structures may involve dynamic processes of strain refraction due to competency contrasts, the effect of anisotropy in the schist, or localised stress field rotation. Deposits have been classified on the basis of host structure kinematics at the time of mineralisation into low angle thrust faults, and high angle extensional fault - fracture arrays. Low angle deposits have a mapped internal geometry that is very different from conventional imbricate thrust systems. This study applied ⁴⁰Ar/�⁹Ar geochronology to selected deposits and has identified at least three distinct mineralisation events have occurred within the central axial belt during the Cretaceous. Relationships between radiometric apparent age and inferred crustal depth reveal that after metamorphism, the onset of cooling and rapid exhumation of the schist belt coincides temporally and spatially with the age of mineralisation and structural position of a regional scale low angle shear zone in Otago.

APA, Harvard, Vancouver, ISO, and other styles

5

Daczko, Nathan Robert. "The Structural and Metamorphic evolution of cretaceous high-P granulites, Fiordland, New Zealand." University of Sydney. Geosciences, 2002. http://hdl.handle.net/2123/822.

Full text

Abstract:

Fiordland is located southwest of South Island of New Zealand. The field area of this thesis is in northern Fiordland, at the boundary of pristine arc rocks (Median Tectonic Zone) and a belt of Paleozoic paragneisses and orthogneisses of variable age that represent the metamorphosed paleo-Pacific Gondwana margin.

APA, Harvard, Vancouver, ISO, and other styles

6

Schulte, Daniel. "Kinematics of the Paparoa Metamorphic Core Complex, West Coast, South Island, New Zealand." Thesis, University of Canterbury. Geological Sciences, 2011. http://hdl.handle.net/10092/5459.

Full text

Abstract:

The Paparoa Metamorphic Core Complex developed in the Mid-Cretaceous due to continental extension conditioning the crust for the eventual breakup of the Gondwana Pacific Margin, which separated Australia and New Zealand. It has two detachment systems: the top-NE-displacing Ohika Detachment at the northern end of the complex and the top-SW-displacing Pike Detachment at the southern end of the complex. The structure is rather unusual for core complexes worldwide, which are commonly characterised by a single detachment system. Few suggestions for the kinematics of the core complex development have been made so far. In this study structural-, micrographic- and fission track analyses were applied to investigate the bivergent character and to constrain the kinematics of the core complex. The new results combined with reinterpretations of previous workers’ observations reveal a detailed sequence of the core complex exhumation and the subsequent development. Knowledge about the influence and the timing of the two respective detachments is critical for understanding the structural evolution of the core complex. The syntectonic Buckland Granite plays a key role in the determination of the importance of the two detachment systems. Structural evidence shows that the Pike Detachment is responsible for most of the exhumation, while the Ohika Detachment is a mere complexity. In contrast to earlier opinions the southwestern normal fault system predates the northeastern one. The Buckland Pluton records the ceasing pervasive influence of the Pike Detachment, while activity on the Ohika Detachment had effect on the surface about ~8 Ma later. Most fission track ages are not related to the core complex stage, but reflect the younger late Cretaceous history. They show post core complex burial and renewed exhumation in two phases, which are regionally linked to the development of the adjacent Paparoa Basin and the Paparoa Coal Measures to the southwest and to the inception of seafloor spreading in the Tasman Sea in a larger context.

APA, Harvard, Vancouver, ISO, and other styles

7

MacKenzie, Douglas James, and n/a. "Structural controls on orogenic gold mineralisation in the Otago Schist, New Zealand and the Klondike Schist, Canada." University of Otago. Department of Geology, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080704.085108.

Full text

Abstract:

Orogenic gold mineralisation in schist terranes with few or no contemporaneous igneous intrusions is poorly understood. It is proposed in this thesis that the structural evolution of such terranes controls the generation of hydrothermal fluid pathways and thus the location of orogenic mineral deposits. Gold mineralisation in the Otago Schist, New Zealand and the Klondike Schist, Canada occurred in the latter phases of greenschist facies metamorphism as well as after metamorphism during Paleozoic-Mesozoic exhumation. In Otago, gold mineralisation occurred at a number of different times and structural levels as the schist belt was exhumed and rocks were brought up through the brittle-ductile transition. In Klondike Schist, gold mineralisation occurred in relatively brittle rocks after a period of regional compression and crustal shortening caused by the stacking of thrust sheets. Gold mineralisation in both schist belts is not associated with any coeval igneous activity. The earliest stage of gold mineralisation in the Otago Schist occurred in the Jurassic when mineralising fluids were progressively focussed into late metamorphic ductile shear zones such as the Hyde-Macraes Shear Zone (HMSZ), east Otago and Rise and Shine Shear Zone (RSSZ), central Otago. Both of these gold-bearing mineralised zones occur along mappable structural discontinuities or boundaries that separate structurally, metamorphically and lithologically distinct blocks. The HMSZ occurs in the hangingwall of an underlying low angle normal fault that juxtaposes mineralised lower greenschist facies rocks on to unmineralised upper greenschist facies rock. The RSSZ occurs in the footwall of an overlying low angle normal fault that juxtaposes unmineralised lower greenschist facies rocks on to mineralised upper greenschist facies rock. The two shear zones did not form as part of a single homogeneous structure. There are several other prospective late metamorphic boundaries that are different from later brittle faults that disrupt the schist. Late metamorphic gold mineralisation is characterised by both ductile and brittle structures, foliation-parallel shears, disseminated gold with sulphides in deformed schist and minor steeply dipping extensional veins. This style of mineralisation is the most prospective but can be subtle in areas without quartz veins. Hydrothermally altered rocks are enriched in gold, arsenic, tungsten and sulphur with minor enrichment of bismuth, antimony, mercury and molybdenum. Disseminated mineralisation in the HMSZ is associated with hydrothermal graphite however there is no hydrothermal graphite in the RSSZ. The next stage of gold mineralisation occurred in the Cretaceous during post-metamorphic exhumation of the schist belt and is characterised by steeply dipping, fault-controlled quartz veins, silicified breccias and negligible wall rock alteration. Most post-metamorphic veins strike northwest such as the ~25 km long Taieri river gold vein swarm, but there are other stibnite and gold mineralised structures that strike northeast (e.g., Manuherikia Fault system) and east-west (e.g., Old Man Range vein systems). The latest recognised stage of gold mineralisation is controlled by structures related to the initiation of the Alpine Fault in the Miocene and is characterised by steeply dipping quartz veins with abundant ankeritic carbonate in veins and ankeritic carbonate with gold in altered rocks. Hydrothermally altered rocks are enriched in arsenic, carbon dioxide and sulphur with minor enrichment of antimony. Gold-bearing veins at Bullendale, central Otago are of this type and are associated with a broad alteration zone. Gold-silver and gold-silver-mercury alloys occur in both Caples and Torlesse Terranes of the Otago Schist. Almost all mercury-bearing gold occurs in east Otago vein systems and mercury-free gold occurs in central and northwest Otago veins, irrespective of host terrane. There is no relationship between depth of vein emplacement and mercury content of gold. The Klondike Schist was emplaced as a series of stacked thrust slices in the Jurassic and thrust-related fabrics are preserved in all thrust slices. Strongly deformed carbonaceous schist horizons are spatially associated with thrust faults and graphite within these units is concentrated along spaced cleavage surfaces. Kink folding is best developed in the uppermost slices of Klondike Schist and overprints thrust-related fabrics. Gold-bearing veins formed in extension fractures controlled principally by pre-existing weaknesses such as kink fold axial surfaces. Normal faults correlated with a period of Late Cretaceous regional extension crosscut kink folds and offset gold mineralised veins. The main stage of mineralisation occurred after major regional compression and thrust stacking and before Cretaceous normal faulting. Gold-bearing veins are widely dispersed throughout the uppermost slices of Klondike Schist and are considered to be a sufficient source for Klondike gold placer deposits. Disseminated gold with pyrite is associated with gold-bearing veins in some Klondike Schist and this disseminated mineralisation expands the exploration target for these veins. Disseminated gold with pyrite, without quartz veins, occurs in some schist lithologies and is associated with chlorite alteration and weak silicification. The arsenic content of gold-mineralised Klondike Schist is much lower than mineralised Otago Schist and background concentrations of arsenic are much lower in Klondike Schist as well. No shear-related mineralisation has been discovered in Klondike Schist but due to its relatively poor exposure, this belt remains prospective for this style of mineralisation.

APA, Harvard, Vancouver, ISO, and other styles

8

Blakely, Tanya Jillaine. "Tree holes as habitat for aquatic and terrestrial invertebrates in mixed broadleaf-podocarp rainforest, New Zealand." Thesis, University of Canterbury. Biological Sciences, 2008. http://hdl.handle.net/10092/1698.

Full text

Abstract:

Little is known about the spatial distribution and abundance of tree holes in New Zealand’s native forests, or the invertebrate communities that they support. I found that tree holes were common on five endemic tree species, belonging to the families Fagaceae and Podocarpaceae in the mixed broadleaf-podocarp rainforest of Orikaka Ecological Area, Buller District, New Zealand. However, tree holes were not uniformly distributed throughout the forest, with more holes found on the three podocarp species, Prumnopitys ferruginea, P. taxifolia and Dacrycarpus dacrydioides, than on Nothofagus fusca or N. menziesii. Nevertheless, Nothofagus fusca had the largest holes of any of the tree species sampled and larger trees generally had larger holes. Large, hole-bearing Nothofagus fusca trees support a specialist hole-dwelling vertebrate fauna in New Zealand and worldwide, tree holes provide habitat for a range of invertebrate species. Using specially-designed emergence traps, I collected invertebrates emerging from naturally-occurring dry tree holes and compared this assemblage with invertebrates inhabiting leaf litter on the forest floor and those dispersing aerially throughout the study area. At the higher taxonomic resolution (i.e., Order or Class), community composition within the tree holes was highly variable, and there was no strong distinction between invertebrates from tree holes, leaf litter or Malaise traps. Moreover, although some beetle species emerging from tree holes were found exclusively in tree holes, most of these were represented by a single individual. Consequently, only minor differences in species composition were detected between beetle assemblages from tree holes, leaf-litter and those aerially dispersing throughout the forest. In contrast, the aquatic invertebrate assemblage within water-filled tree holes was highly distinctive from that in ground-based freshwater ecosystems, with only six aquatic taxa in common between all freshwater habitats. Using experimental water-filled tree-hole microcosms, I found that species richness and community composition within these microcosms were primarily driven by resource concentration, although habitat quality (i.e., water chemistry parameters) was also an important determinant of the identity and composition of colonising species. Overall, my study has shown that tree holes are common in the study area, and are likely to be more abundant in New Zealand’s indigenous forests than previously thought. Moreover, these generally small, discrete forest ecosystems support a diverse array of terrestrial invertebrates as well as a distinctive aquatic invertebrate community that is primarily structured by organic matter resource availability. These findings not only represent an important advance in our knowledge of New Zealand’s freshwater invertebrate biodiversity, but also highlight the need for further investigation into these unique forest canopy habitats which may well be at risk from deforestation and land use change.

APA, Harvard, Vancouver, ISO, and other styles

9

Barnes, Philip M. "Structural styles and sedimentation at the southern termination of the Hikurangi subduction zone, offshore North Canterbury, New Zealand." Thesis, University of Canterbury. Geology, 1993. http://hdl.handle.net/10092/4702.

Full text

Abstract:

In the northern region of South Island, New Zealand, a major tectonic transition occurs in the obliquely convergent Australia-Pacific plate boundary. The southern end of the Hikurangi subduction zone terminates against the Chatham Rise, a submerged continental plateau on the Pacific Plate, which is too buoyant to be subducted. Relative plate motion that is accommodated along the Hikurangi margin is transferred by a complex arrangement of faults, to a zone of transpressive, continental collision across the Southern Alps. A detailed study of offshore seismic-reflection profiles, sediment cores and bathymetry from the north Canterbury continental margin and north-western Chatham Rise reveals the complex interactions between late Cenozoic sedimentation and tectonics at the southern termination of the Hikurangi subduction zone. The north Canterbury shelf and the NW Chatham Rise slope are separated by major submarine canyons that link the shelf with the 3000 m-deep Hikurangi Trough. The sedimentary succession beneath the shelf and slope attains a maximum thickness of about 2 km and is inferred to be underlain by Torlesse terrane basement of Mesozoic age. The late Cenozoic stratigraphy of both regions has been established by correlating unconformity-bounded sedimentary units between seismic-reflection profiles, sampling the units in cores from exposures at the seabed, and dating the sediments by foraminifera and nannoflora biostratigraphy. Tectonic structures have been mapped from seismic profiles and the stratigraphy has been used to constrain the structural and sedimentary evolution of each area. The north Canterbury shelf and the NW Chatham slope exhibit contrasting tectonic and sedimentation styles, which reflect differences in proximity to sediment sources, bathymetry, physical oceanography, sedimentation response to global climate cycles and relative sea-level changes, and different stresses imposed on the basement rocks within the plate-boundary zone. Late Quaternary sedimentation patterns on the NW Chatham slope and in the southern Hikurangi Trough have been studied using 3.5 kHz echo-character mapping. The slope is dominated by current-controlled sedimentary processes, whereas turbidite processes characterise the adjacent part of the southern Hikurangi Trough. On the slope north of Mernoo Saddle (a 580 m-deep depression between the South Island shelf and the Chatham Rise) a 160 x 30 km zone of current erosion occurs between 700 m and 2300 m water depths. Within this region are several northeast trending channels, 5-20 km wide and up to 105 km long, scoured obliquely down-slope. These scours are inferred to have been formed by a northward flowing current of Antarctic Intermediate Water passing through the Mernoo Saddle, then braiding as it cascaded down and across the mid-slope before merging again further east into a contour current on the unstable lower slope of the northern Chatham Rise. The lower slope between and below the scours comprises a complex of coalescing sediment drifts. The adjacent Hikurangi Trough is characterised by a canyon and levee-channel system that guide turbidites from the eastern South Island margin and Cook Strait. On the trough floor is a meandering axial channel up to 10 km wide, with a left-bank dominated levee off Cook Strait where the trough widens. Within the down-slope thickening, late Cenozoic succession on the NW Chatham slope there is a stratigraphic change in acoustic impedance that is inferred to mark a change from predominantly carbonate to terrigenous sedimentation in the Late Miocene (c. 9-10 Ma). This change might reflect an increase in uplift and erosion of the Southern Alps at this time. Analysis of 13 unconformity-bounded seismic units of Pliocene-Recent age indicates an episodic history of mid-bathyal (c. 700-2300 m) current erosion and deposition on the NW Chatham slope. Erosion began in the mid-Pliocene and was most widespread in the Late Pleistocene, when several regional scale erosion surfaces developed. The regional extent of the older surfaces differ from the pattern of oblique-to-slope, en echelon, scour channels and associated sediment drifts which are related only to the five youngest depositional units(< 0.25 Ma). All erosional or non-depositional unconformities between the 13 Plio-Pleistocene seismic units resulted from major velocity changes in the northward, mid-bathyal flow over the Mernoo Saddle. Therefore, the sedimentary units and their intervening unconformities have a different origin to sea-level-controlled sequences in the Vail/Exxon stratigraphic model. The eight youngest seismic units are Late Pleistocene and have a cyclicity of about 57-75 ka, which is similar to high-order (40 and 100 ka) glacio-eustatic sea-level cycles. The older units, deposited between Early Pliocene and Late Pleistocene, have a longer frequency of about 750 ka. The similarity of the Late Pleistocene sequence cyclicity to that of high-order glacio-eustatic cycles, together with consideration of the physical oceanography, a recent phase of reduced erosion during the Holocene, and the inferred subsidence history of the region collectively suggest that the paleoceanographic fluctuations causing the sequences are related to high-amplitude Plio-Pleistocene glacial-interglacial climatic oscillations superimposed on the late Cenozoic subsidence of Mernoo Saddle. The north Canterbury inner-middle shelf is underlain by twelve unconformity bounded seismic units of Late Pliocene-Early Pleistocene to Recent age. The units consist predominantly of terrigenous silty mud and thin layers of gravel, which are inferred to have been deposited in c. < 70-80 m water depth predominantly during transgressions and relative highstands of high amplitude, glacio-eustatic sea-level cycles. Erosional unconformities of middle Pleistocene to Recent age have been progressively tilted seaward as a result of contemporaneous coastal uplift and outer shelf subsidence. The north-western corner of the Chatham Rise has been extending by normal faulting since the Late Miocene (c. 8-6 Ma). The North Mernoo Fault Zone (NMFZ) is a 100 x 300 km extensional province that evolved contemporaneously with offshore sedimentation and with the plate-boundary zone in northern South Island. Growth faults are characteristic, but the distribution of faulting has varied temporally; The fault zone is seismically active and consists of a domino-style array of overlapping, southward dipping normal faults which are typically 2-5 km apart and trend roughly east-west at a high angle to the plate-boundary zone. Late Quaternary surface traces are widely distributed on the mid-upper continental slope but many surface scarps are poorly preserved due to extensive erosion of the seafloor. Despite the wide distribution of faulting, late Cenozoic extensional strain is < 2%. The geometry of the NMFZ is partially inherited from older basement structures. Many of the late Cenozoic faults are reactivated Late Cretaceous and Eocene normal faults which developed during periods of widespread extension of the New Zealand region, in tectonic settings different from now. Two possible models for extension of the edge of continental Pacific Plate are considered: (1) lateral buckling of the upper continental crust across the southern termination of the Hikurangi subduction zone; and (2) flexure of the NW Chatham Rise as the region is bent downward into the southern end of the Hikurangi subduction zone. The extensional NMFZ is one of three offshore fault systems that almost merge together over the southern end of the Hikurangi subduction zone. The western end of the NMFZ crosses submarine canyons at the southern end of the Hikurangi Trough and extends to within 20 km of two opposite-verging, NE-trending fold and thrust fault systems on the north-eastern South Island continental margin. One fold and thrust system verges eastward and represents the southern part of the Hikurangi margin imbricated frontal wedge that is deforming the Marlborough continental slope above the southern part of the Hikurangi subduction zone. The other fold and thrust fault system verges north-westward and is deforming the north Canterbury shelf to the west of the NMFZ. In addition to tilting of the north Canterbury shelf, the inner edges of the Plio-Pleistocene units have been progressively deformed since the middle Pleistocene. Gentle, asymmetric folds up to 35 km long are inferred to be developing above the propagating tips of SE-dipping thrust faults. Some structural elements of the fold and thrust system may be reactivated Late Cretaceous extensional faults. The fold and thrust region extends 20 km offshore between central Pegasus Bay and Kaikoura. The north-eastern end of the zone extends to within 20 km of the extensional NMFZ, but these two fault systems are not linked kinematically, Two possible tectonic models for the north Canterbury coastal region are considered. The preferred model involves NW-SE oriented, upper-crustal shortening of much of the north Canterbury region, which is required to accommodate a component of the relative plate motion in northern South Island. A comparison with other obliquely convergent plate boundaries and with other tectonic settings where continental extensional faulting is occurring today, suggests that the style of tectonic interactions at the southern termination of the Hikurangi subduction zone is rare in the world.

APA, Harvard, Vancouver, ISO, and other styles

10

Smart, Martha. "The application of the theory of planned behaviour and structural equation modelling in tax compliance behaviour: a New Zealand study." Thesis, University of Canterbury. Accounting and Information Systems, 2012. http://hdl.handle.net/10092/7528.

Full text

Abstract:

The Theory of Planned Behaviour (TPB) has received considerable attention in the behavioural literature, but not in the tax compliance domain. The key purpose of this study is to determine the influence of selected tax compliance variables on tax compliance behaviour. The secondary objectives are to explore the applicability of the TPB in predicting and explaining tax compliance behaviour, and to provide justification for the application of Structural Equation Modelling (SEM) employing the Partial Least Squares (PLS) statistical software or PLS-Graph (which has not been widely used in tax compliance research). The results provide evidence supporting the use of PLS-Graph in undertaking SEM analysis in tax compliance research, especially when smaller samples are involved and the data collected may not be normally distributed. This study also demonstrated the wide applicability of the TPB, including its application in tax compliance research. This study modified and extended the standard TPB behavioural model with the inclusion of a number of economic and noneconomic constructs. Most of the constructs used for this study are grounded in a number of theories: Deterrence Theory; Procedural Justice Theory; and Motivational Posturing Theory; in addition to the TPB. Data to test the research hypotheses was collected using a mail and a web-based survey. The results of this study suggest that noneconomic variables, such as beliefs and attitudes, are good predictors of tax compliance behaviour. Consistent with the majority of studies, the most influential factor in predicting and explaining tax compliance behaviour (through the mediating effects of behavioural intention) is attitude towards the behaviour. Other factors such as personal, social and societal norms were also significant predictors of tax compliance behaviour. Perceived behavioural control was only significant for the taxpayers but not for the tax agents. In contrast, perception of the tax authority was significant for New Zealand tax agents, but not for taxpayers. The results also suggest that tax compliance behaviour is complex, and different determinants of compliance behaviour affects different sub-groups of taxpayers differently. The results lend further support to the literature that indicates that taxpayers are not a homogeneous group. This study also found that taxpayers and tax agents generally perceive tax noncompliance as less serious relative to a number of other similar civil offences. This perception may explain why respondents (from both sample groups) who were penalised for noncompliance felt that the penalties imposed were harsh, unfair and excessive. Overall, the current study illustrates the importance of incorporating noneconomic variables comprising beliefs, attitudes, and norms, with widely used economic variables such as penalties and other enforcement tools, for achieving an optimal compliance strategy.

APA, Harvard, Vancouver, ISO, and other styles

11

Nicol, Andrew. "Structural styles and kinematics of deformation on the edge of the New Zealand plate boundary zone, mid-Waipara region, North Canterbury." Thesis, University of Canterbury. Geology, 1991. http://hdl.handle.net/10092/4971.

Full text

Abstract:

In North Canterbury, on the SE edge of the New Zealand plate boundary zone, deformation in late Cretaceous and younger cover rocks is complex. Detailed mapping of the cover sequence (which is about 1 km. thick), has revealed a pattern of synchronous faulting and folding about orthogonal E-ESE and N-NNE orientations younger than early Pleistocene. Complex and irregular basin and dome fold interference patterns are defined by distinctive limestone marker horizons, and partial star, triangular and corrugated hose fold surface geometries (defined by structure contours) are common. These geometries are often associated with folds that vary in shape along their hinge line and secondary folds developed oblique to the main interfering fold sets. Fold interference geometries are also characterised by composite conical geometries, composed of several distinct cone segments. Folding in the cover sequence has developed in response to: (1) fault propagation and displacement in the basement; and, (2) shortening within the fault bounded blocks. The folds related to faulting are asymmetric and parallel the major faults. Fold amplitudes of 0.5-1.6 km. are proportional to vertical fault displacements, and wavelengths of 5-20 km. are approximately equal to the strike-normal distances between the major faults. Fold interference patterns are indicative of the styles and levels of activity of the orthogonal faulting. Analysis of fault and slickenside striation geometries suggests that faulting is dominated by oblique-reverse faults and thrusts, which verge north, south, east and west. Interspersed with the regional contractional faulting are, local areas of E-ESE oblique-normal faults, inferred to be reactivated late Cretaceous structures. Computed stress tensors derived from minor fault motion data suggest that the principal stress axes most commonly plunge at shallow to moderate angles. Locally they have variable orientations but regionally these data imply a predominant NW-SE compression, comparable to local geodetic shortening and focal mechanism compression directions. Geometric and spatial analysis of large numbers of sets of small scale, mainly brittle structures, documents the local history of deformation. Multiple joint, pressure solution seam and stylolite, macrofracture and mesofault sets record only two periods of deformation since the mid-Cenozoic. The first was a weak regional mid-late Oligocene compression; the second involving a NW-SE compression since the Pliocene. Post Pliocene deformation is characterised by initial NW-SE shortening, followed by approximate N-S and E-W shortening associated with folding. The sequence of structural development during the late Pliocene and Pleistocene implies a progressive increase in the intensity of deformation and a rapid widening of the plate boundary zone during the last 2-3 ma. The mainly contractional deformation in North Canterbury, commonly associated with thrusting to the NW, is distinct from the major right-lateral and eastward directed thrust tectonics in Marlborough. This not only reflects a difference between inner and outer plate boundary deformation, but also the diminishing influence of subduction related tectonics.

APA, Harvard, Vancouver, ISO, and other styles

12

Duffy, Brendan Gilbert. "The Structural and Geomorphic Development of Active Collisional Orogens, from Single Earthquake to Million Year Timescales, Timor Leste and New Zealand." Thesis, University of Canterbury. Department of Geological Sciences, 2012. http://hdl.handle.net/10092/7527.

Full text

Abstract:

The structure and geomorphology of active orogens evolves on time scales ranging from a single earthquake to millions of years of tectonic deformation. Analysis of crustal deformation using new and established remote sensing techniques, and integration of these data with field mapping, geochronology and the sedimentary record, create new opportunities to understand orogenic evolution over these timescales. Timor Leste (East Timor) lies on the northern collisional boundary between continental crust from the Australian Plate and the Banda volcanic arc. GPS studies have indicated that the island of Timor is actively shortening. Field mapping and fault kinematic analysis of an emergent Pliocene marine sequence identifies gentle folding, overprinted by a predominance of NW-SE oriented dextral-normal faults and NE-SW oriented sinistral-normal faults that collectively bound large (5-20km2) bedrock massifs throughout the island. These fault systems intersect at non-Andersonian conjugate angles of approximately 120° and accommodate an estimated 20 km of orogen-parallel extension. Folding of Pliocene rocks in Timor may represent an early episode of contraction but the overall pattern of deformation is one of lateral crustal extrusion sub-parallel to the Banda Arc. Stratigraphic relationships suggest that extrusion began prior to 5.5 Ma, during and after initial uplift of the orogen. Sedimentological, geochemical and Nd isotope data indicate that the island of Timor was emergent and shedding terrigenous sediment into carbonate basins prior to 4.5 Ma. Synorogenic tectonic and sedimentary phases initiated almost synchronously across much of Timor Leste and <2 Myr before similar events in West Timor. An increase in plate coupling along this obliquely converging boundary, due to subduction of an outlying continental plateau at the Banda Trench, is proposed as a mechanism for uplift that accounts for orogen-parallel extension and early uplift of Timor Leste. Rapid bathymetric changes around Timor are likely to have played an important role in evolution of the Indonesian Seaway. The 2010 Mw 7.1 Darfield (Canterbury) earthquake in New Zealand was complex, involving multiple faults with strike-slip, reverse and normal displacements. Multi-temporal cadastral surveying and airborne light detection and ranging (LiDAR) surveys allowed surface deformation at the junction of three faults to be analyzed in this study in unprecedented detail. A nested, localized restraining stepover with contractional bulging was identified in an area with the overall fault structure of a releasing bend, highlighting the surface complexities that may develop in fault interaction zones during a single earthquake sequence. The earthquake also caused river avulsion and flooding in this area. Geomorphic investigations of these rivers prior to the earthquake identify plausible precursory patterns, including channel migration and narrowing. Comparison of the pre and post-earthquake geomorphology of the fault rupture also suggests that a subtle scarp or groove was present along much of the trace prior to the Darfield earthquake. Hydrogeology and well logs support a hypothesis of extended slip history and suggests that that the Selwyn River fan may be infilling a graben that has accumulated late Quaternary vertical slip of <30 m. Investigating fault behavior, geomorphic and sedimentary responses over a multitude of time-scales and at different study sites provides insights into fault interactions and orogenesis during single earthquakes and over millions of years of plate boundary deformation.

APA, Harvard, Vancouver, ISO, and other styles

13

Hermann, Andreas. "Ab initio calculations of water and ice : structural, electronic and optical properties : a thesis submitted in partial fulfillment of the requirements of the degree of Doctor of Philosophy at Massey University, Albany, New Zealand." Massey University, 2009. http://hdl.handle.net/10179/909.

Full text

Abstract:

Extended aqueous systems, crystalline ice and liquid water, are studied computationally to investigate their ground state and excited state properties. Methods from solid state physics and quantum chemistry are combined to shed light on some of the unusual properties of water and ice. For the ground state of crystalline ice, density functional theory (DFT) calculations are compared to an ab initio incremental ansatz that utilizes periodic Hartree-Fock together with localized electron correlation calculations. It is shown that the many-body decomposition of the electron correlation converges very fast, allowing the achievement of excellent agreement with experimental data even when limiting correlation energy contributions to two-body terms only. The incremental method is utilized by a computer program that combines the periodic and localized calculations, and allows for structural optimization of the system of interest. The adsorption of water molecules on the surface of ice is studied using DFT. Adsorption is found to be favoured on non-crystallographic adsorption sites, and a slight tendency towards the formation of rough surfaces is reported. The localization of excess electrons at the surface of ice is facilitated by coadsorbed water molecules. For a correct theoretical description of the latter, a self-interaction correction scheme for the excess electron has to be used. However, it is sufficient to limit the self-interaction correction to the excess electron only, since the neutral ice surface itself is well described within conventional DFT. The self-interaction correction scheme is incorporated into a commonly used DFT program package. Optical excitations of crystalline ice are calculated using many-body perturbation theory. Solving the two-particle Bethe-Salpeter equation yields optical spectra in excellent agreement with experimental data. Based on this agreement, an embedding model is developed that reduces the hydrogen bond network to its most important contribution. The model is applied to crystalline ice, where it reproduces the experimental spectral features, and to microscopic liquid water structures obtained from molecular dynamics simulations, where it reproduces the energy shift of the first absorption peak and gives overall good agreement with experiment. The driving force of water’s anomalous optical behaviour is identified.

APA, Harvard, Vancouver, ISO, and other styles

14

Adamson, Thomas Keeley. "Structural development of the Dun Mountain Ophiolite Belt in the Permian, Bryneira Range, western Otago, New Zealand : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Geological Science at the University of Canterbury /." Thesis, University of Canterbury. Geological Sciences, 2008. http://hdl.handle.net/10092/1587.

Full text

Abstract:

The deformed Permian Dun Mountain Ophiolite Belt (DMOB) forms the basement of the Dun Mountain-Maitai terrane and is traceable through the entire length of New Zealand. The DMOB contains a variably serpentinised mantle portion and a crustal portion containing gabbros, dolerites, cross cutting dikes and extrusives, together they are similar to oceanic crust. The initial crustal portion, however, is atypical when compared to other ophiolites, being thin and lacking a sheeted dike complex, but has well spaced inclined intrusive sheets and sills. At least four post-Permian deformation periods affect the DMOB; collision and rotation during emplacement of the DMOB on the Gondwana margin, compression during Mesozoic orogenies, extensional deformation during the Gondwana break-up and transpressive deformation related to the modern plate boundary through New Zealand. Structural work in the Northern Bryneira Range focused on well preserved outcrops to investigate crustal growth and contemporaneous deformation during the Permian. Structural evidence of Permian deformation was determined by examination of pseudostratigraphy, structures constrainable to the Permian, and the geometric relationships with the overlying Maitai sedimentary sequence. Crosscutting by intrusive phases was used to determine a chronological order of crustal growth and deformation episodes. It was concluded that all deformation was extensional and that two major phases of magmatism were separated by a period of deformation and were followed by ongoing syn-sedimentary deformation during the deposition of the Maitai Group. After removal of Mesozoic rotation, the resulting orientations of paleo-horizontal markers and diverse orientations of intrusive sheets were analysed. Two hypothesises were tested to assess the origin of inclined intrusive sheets: a) that the diverse orientations were the result of tectonic rotation coeval with the intrusion of dikes. b) that primary orientations of the sheets had been diverse. Results show that the sheets were intruded with diverse orientations, probably related to variation in the principle horizontal stress over time. Further rotation of the assemblage of sheets occurred during the last stages of magmatism and during the subsequent period of sedimentation. The last stage probably relates to large scale normal faulting during the development of the sedimentary basin. iii

APA, Harvard, Vancouver, ISO, and other styles

15

Liu, Yunhao. "Structural and biochemical analysis of HutD from Pseudomonas fluorescens SBW25 : a thesis submitted in fulfilment of the requirements for the degree of Master of Science in Molecular Biosciences at Massey University, Auckland, New Zealand." Massey University, 2009. http://hdl.handle.net/10179/1074.

Full text

Abstract:

Pseudomonas fluorescens SBW25 is a gram-negative soil bacterium capable of growing on histidine as the sole source of carbon and nitrogen. Expression of histidine utilization (hut) genes is controlled by the HutC repressor with urocanate, the first intermediate of the histidine degradation pathway, as the direct inducer. Recent genome sequencing of P. fluorescens SBW25 revealed the presence of hutD in the hut locus, which encodes a highly conserved hypothetical protein. Previous genetic analysis showed that hutD is involved in hut regulation, in such a way that it prevents overproduction of the hut enzymes. Deletion of hutD resulted in a slow growth phenotype in minimal medium with histidine as the sole carbon and nitrogen source. While the genetic evidence supporting a role of hutD in hut regulation is strong, nothing is known of the mechanism of HutD action. Here I have cloned and expressed the P. fluorescens SBW25 hutD in E. coli. Purified HutD was subjected to chemical and structural analysis. Analytic size-exclusion chromatography indicated that HutD forms a dimer in the elution buffer. The crystal structure of HutD was solved at 1.80 Å (R = 19.3% and Rfree = 22.3%) by using molecular replacement based on HutD from P. aeruginosa PAO1. P. fluorescens SBW25 HutD has two molecules in an asymmetric unit and each monomer consists of one subdomain and two ß-barrel domains. Comparative structural analysis revealed a conserved binding pocket. The interaction of formate with a highly conserved residue Arg61 via salt-bridges in the pocket suggests HutD binds to small molecules with carboxylic group(s) such as histidine, urocanate or formyl-glutamate. The hypothesis that HutD functions via binding to urocanate, the hut inducer, was tested. Experiments using a thermal shift assay and isothermal titration calorimetry (ITC) analysis suggested that HutD binds to urocanate but not to histidine. However, the signal of HutD-urocanate binding was very weak and detected only at high urocanate concentration (53.23 mM), which is not physiologically relevant. The current data thus does not support the hypothesis of HutD-urocanate binding in vivo. Although the HutD-urocanate binding was not confirmed, this work has laid a solid foundation for further testing of the many alternative hypotheses regarding HutD function.

APA, Harvard, Vancouver, ISO, and other styles

16

Hector, Christopher James. "Wage Structures and Employment Outcomes in New Zealand, and Their Relationship to Technological Change." The University of Waikato, 2007. http://hdl.handle.net/10289/2663.

Full text

Abstract:

After 100 years at an historically low level, inequality began to rise in the late 20th century, a trend which was especially marked in the English-speaking countries including New Zealand. Various explanations have been advanced, but internationally the most favoured theory is skill-biased technological change, driven by the new information and communication technologies. This thesis used income and wage data from the New Zealand Population Census and the New Zealand Income Survey to examine wage trends between 1991 and 2004. As in other developed countries wage dispersion was increasing in the 1990s, though it appears to have slowed since 2001, and the increased inequality is strongly correlated with workers' skills and qualifications. There is also a correlation between new technology and earnings inequality, but this appears to be attributable to the demand for skills in the industries which are changing fastest, rather than anything intrinsic to the new technology.

APA, Harvard, Vancouver, ISO, and other styles

17

MacAskill, Ursula Kate. "A structural investigation of squash aspartic peptidase inhibitor (SQAPI) using Nuclear Magnetic Resonance spectroscopy (NMR) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University, Palmerston North, New Zealand." Massey University, 2007. http://hdl.handle.net/10179/985.

Full text

Abstract:

Peptidases are enzymes that hydrolyse peptide bonds. This potentially dangerous activity is regulated by post translational modification and peptidase inhibitors. The best characterized of the peptidase inhibitors are the serpins whilst the aspartic peptidase inhibitors are the least characterized. Aspartic peptidase inhibitors are rare with only nine known sources. However, they are of great interest because they play an important part in several human diseases such as metastasis of breast cancer cells, Candida albicans infections and HIV. The aims of this research project were to investigate the structure of Squash Aspartic peptidase inhibitor (SQAPI), using nuclear magnetic resonance spectroscopy (NMR). This required large amounts of relatively pure and isotopically labeled protein, which was achieved by heterologously expressing His-tagged rSQAPI fusion protein in Escherichia coli using a rich to minimal media transfer method. The fusion protein was purified with a nickel column and the N-terminal extension containing the His6-tag was removed by cleavage of the fusion protein with enterokinase followed by nickel column purification. Preliminary 1 dimensional NMR spectra indicated that SQAPI was folded in solution at pH 3. This was confirmed from the results of a preliminary 15N-edited HSQC. These results combined justified the production of a 15N 13C labeled SQAPI sample for the collection of further NMR spectra. From the spectra produced with double labeled protein the backbone and the side-chain atoms of SQAPI were assigned. The chemical shifts are currently 88.89% complete and have been submitted to the biological magnetic resonance bank (BMRB). A preliminary estimate of the secondary structure of SQAPI has been calculated from the HNHA spectrum suggesting that the SQAPI structure has some similarity to the previously proposed model of the inhibitor’s structure. Furthermore, the region corresponding to the putative binding loop on the model of SQAPI was found to be mobile and deuterium exchange experiments indicate that the SQAPI structure is more globular than open.

APA, Harvard, Vancouver, ISO, and other styles

18

Huang, Li Ting. "Teaching Buddhism in New Zealand universities." Click here to access this resource online, 2009. http://hdl.handle.net/10292/779.

Full text

Abstract:

This thesis is an investigation into the university-level teaching of Buddhism in New Zealand, which has developed as part of the international spread of education about Buddhism for both Buddhists and non-Buddhists. The study was based on Interpretivism and accordingly sought to understand and interpret university teachers’ perceptions and experiences about their teaching of Buddhism; as they engage with the students' learning in this field. Semi-structured in-depth interviews were employed as the primary research method. All seven university teachers who teach Buddhism in New Zealand were invited to be the participants. Six university teachers participated in this research-study. Five of them were academic teachers, respectively teaching at Religious Studies of Massey, Victoria and Otago. Another one was a New Zealand-born Zen teacher who had been teaching a Zen meditation workshop at Auckland University of Technology for several years, and taught two Buddhism-related courses at the University of Auckland. These participants were chosen according to the information provided on official websites of New Zealand universities. The findings from the study showed that the university-level teaching of Buddhism in New Zealand, though growing, had been limited by the number of teachers and students. As fewer students were primarily interested in Buddhism, outward funding support appeared to be a very important factor for its future development. In terms of teachers’ role, objective-outsider remained the main position for scholars and scholar-practitioners in teaching Buddhism in university classroom. In addition to the pursuit of knowledge, there were also alternative educational opportunities, such as Zen workshop, for university staffs and students to learn Buddhism, outside university classroom. This thesis is significant in that it provided a bibliography and a set of data for the university-level teaching of Buddhism in the West, particularly New Zealand It established a space for future educational research into for the university-level teaching of Buddhism in the West, as part of the field of’ Buddhism and Education.’ In future studies, the limited approaches to teaching Buddhism in universities could be investigated on the basis of the literatures and findings of this study.

APA, Harvard, Vancouver, ISO, and other styles

19

Markowitz, Timothy Michael. "Social organization of the New Zealand dusky dolphin." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/537.

Full text

Abstract:

Social organization of dolphins in extensive societies has not been well studied. Off Kaikoura, New Zealand, thousands of dusky dolphins (Lagenorhynchus obscurus) gather, feeding nocturnally on deep scattering layer prey, resting and socializing diurnally. During 1997-2003, interval sampling was used to monitor large assemblages numbering hundreds (n=169), smaller mating groups (mean+s.e.=7+1.6 adults, n=42), mother-calf nurseries (mean+s.e.=13+1.6 adults, 1+0.5 juveniles, 4+0.7 calves and 1+0.4 neonates, n=41), and non-mating adult groups (mean+s.e.= 9+1.3 adults, 1+0.2 juvenile, n=37). Group size, distance from shore (east), ranging along shore (north), traveling, inter-individual distance, and noisy leaping peaked in winter (n=39), with dolphins maintaining closer proximity to each other in smaller, more restful groups, closer to shore during the spring-summer-autumn (n=234) reproductive seasons. Dolphin groups were found closest to shore (west) during early morning, spread out and leaping often. Resting peaked at midday in tight groups. Late in the day, dolphins spread out, moving eastward (offshore) in preparation for feeding. Large groups exhibited coordinated travel, with noisy leaps as a directional signal. "Mating of the quickest" occurred in groups of (median) 6 males chasing 1 female. Leaping rarely occurred in restful nurseries, which at times associated with Hector's dolphins (Cephalorhynchus hectori). Other mixed-species groups included common dolphins (Delphinus delphis), southern right whale dolphins (Lissodelphis peronii), long-finned pilot whales (Globicephala malaena), and bottlenose dolphins (Tursiops truncatus). Killer whales (Orcinus orca) elicited predator assessment and evasion. Whale riding occurred with larger whales. Residence was seasonal, with 1,969+814.9 from a population of 12,626 dolphins spending 103+38.0 days in Kaikoura (mean+s.e., mark-recapture mortality, single-season lagged-ID emigration models, n=153 weeks). Dolphins (n=39) summering in Kaikoura migrated to the Marlborough Sounds in winter, where small, coordinated groups foraged diurnally on schooling fishes in shallow bays, often associated with sea birds and New Zealand fur seals (Arctocephalus forsteri). Aquaculture may threaten dusky dolphin foraging habitat in Admiralty Bay, where an estimated 220 dolphins gathered to feed each winter. Photo-identification research, enhanced by digital techniques, demonstrated a structured fission-fusion society. Dusky dolphins associated with preferred long-term (>1,000 days) hunting companions in Admiralty Bay and non-random casual acquaintances (200 days) in Kaikoura (lagged-association models).

APA, Harvard, Vancouver, ISO, and other styles

20

Shergill, Gurvinder Singh. "Strategy, structure and performance in New Zealand quoted companies." Thesis, University of Canterbury. Business Administration, 1989. http://hdl.handle.net/10092/4371.

Full text

Abstract:

This thesis investigated the extent of diversification in New Zealand companies and its effect on their administrative structure and performance. So far there has not been any study done on the diversification process of New Zealand companies although rapid changes are taking place in their strategic posture. In the second half of the twentieth century the corporate profile in advanced countries like the USA and UK had undergone significant changes as a result of diversification strategies by their business corporations. Diversification is now becoming a major corporate strategy and hence it would be useful for corporate managements, shareholders, financial institutions and other corporate investors, public policy makers and researchers to know the effectiveness of diversification in improving profitability and growth, and reducing risk. Though theoretical and empirical studies done abroad by financial, economic and business researchers suggest that only certain categories of diversification would result in higher performance, a systematic study of this subject is yet to be carried out in New Zealand. This study attempts to accomplish this. This study addresses the following issues: (1) Have the diversification strategies affected the administrative structure of the companies and which structure is the best performer? (2) Does the performance differ among the different types of diversification strategies, for example, between related and unrelated diversification? (3) Does the strategy-structure 'fit' affect the performance of companies? A multi-industry, multi-company approach involving a sample size of 103 New Zealand listed companies in the manufacturing and non-manufacturing sector is used for establishing generalizability of the findings. Adjustment for factors such as size, industry participation, leverage and risk are also incorporated in the design of the study. The performance measures used are in the dimensions of growth and profitability. Findings of this study suggest that in general diversification is useful for reducing the risk and improving the growth and profitability. However, where diversification shows significant improvement over single business strategy, it is in the areas of reduction of risk and improving overall performance. Related diversified companies performed better than the unrelated diversifiers. Regarding the structure, division ally organized companies are having better performance, followed by holding and functional structure. Companies in the strategy-structure 'match' group are having superior performance than the mis-matched category. Finally this study discusses the implications of the findings and suggests areas for future research.

APA, Harvard, Vancouver, ISO, and other styles

21

Gollan, Hugh. "The New Zealand dairy industry--international trade & industry structure." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13343.

Full text

Abstract:

Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1991.
Title as it appears in the June, 1991 M.I.T. Graduate List: International trade in dairy products and the New Zeland industry.
Includes bibliographical references.
by Hugh Gollan.
M.S.

APA, Harvard, Vancouver, ISO, and other styles

22

Sherburn, Steven. "Structure, seismicity, and tectonics of the Taranaki region, New Zealand." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614757.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Shelton, Deborah Ellen. "Dusky dolphins in New Zealand: group structure by sex and relatedness." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4970.

Full text

Abstract:

The sex of and genetic relatedness among interacting individuals are known to be biologically fundamental features that characterize the composition of animal groups. Current work continues to illuminate reasons for the variety of animal social patterns, including patterns in group membership. I investigated the composition of dusky dolphin groups relative to sex and relatedness at two locations in New Zealand. In Kaikoura, dusky dolphins are found year-round, foraging nocturnally on verticallymigrating prey and socializing in distinct group types (mating, nursery, and adult) during the day. By contrast, dusky dolphins use Admiralty Bay, where they feed diurnally on small schooling fishes, primarily in the winter. Molecular sexing revealed the sex of 107 dusky dolphins. The Kaikoura data support previous findings that small mating groups consist mostly of males and indicate that small adult groups can consist of either or both sexes. In Admiralty Bay, the percentage of female dolphins present during the study was estimated to be only 7.4%Ã¢ÂÂ22.2% (95% confidence interval, n=88). A randomization test further indicates that dusky dolphins in Admiralty Bay grouped preferentially with same-sex individuals. Nuclear and mitochondrial markers were used to investigate patterns of relatedness. Dusky dolphins sampled in Kaikoura (n=17) and Admiralty Bay (n=47) were genotyped at seven microsatellite loci, and genetic relatedness among all genotyped pairs was estimated. A randomization test indicates that dusky dolphins did not group preferentially by relatedness in Admiralty Bay. Grouping history for 13 genotyped samples was also known from a multi-year photographic record of individually distinctive dusky dolphins. No relationship was found between these longer-term grouping patterns and genetic relatedness. The d-loop region of the mitochondrial DNA (mtDNA) was sequenced for 197 dusky dolphins. The pattern of grouping among dolphins with different haplotypes indicates that dusky dolphin groups are not strongly structured by maternal lineages. However, data from eight individual dusky dolphins hint that nursery groups in Kaikoura tend to consist of dolphins that share a maternal ancestor. This investigation raises many questions about the nature of dusky dolphin social organization and suggests promising avenues for finer-grained investigations into the causes and consequences of dusky dolphin group structure.

APA, Harvard, Vancouver, ISO, and other styles

24

Campbell, Heather, and n/a. "Partitioning of plate boundary deformation in South Westland, New Zealand : controls from reactivated structures." University of Otago. Department of Geology, 2005. http://adt.otago.ac.nz./public/adt-NZDU20060705.150820.

Full text

Abstract:

The Australian-Pacific plate boundary is an uncomplicated structure along most of its length in the South Island, New Zealand. In South Westland, south of the Arawata River, however, several terranes converge onto the Alpine fault. Inherent anisotropies arising from the position of pre-existing fault structures, lithological contacts and rheological heterogeneities within these give rise to an atypically diffuse and complex zone, the overall geometry of which resembles a regional scale transpressive flower structure. The flower structure is a broad deformation zone 60 km in length extending approximately 7 km from the Alpine fault to its eastern limit, the Dun Mountain Ophiolite Belt. Integral parts of the structure are the Hollyford Fault System and the Livingstone Fault System. The area is characterised by an array of left-stepping, subparallel faults with an average 060� strike linked by 020� striking structures. All fault traces offset Quaternary features. Fractions of the total interplate slip are partitioned across the reactivated structures. Additionally, kinematic indicators reveal partitioning of strike-slip and oblique/dip-slip deformation across the related secondary fault zones. The behaviour of the plate boundary zone in South Westland is fundamentally controlled by reactivation of the Hollyford Fault System and the Livingstone Fault System which partition slip away from the Alpine fault. As a consequence, the eastward transferral of slip onto the curved geometry of the converging fault systems has ultimately created a left-stepping contractional regime, the equivalent of a restraining bend in the plate boundary zone. The competent Dun Mountain Ophiolite Belt controls the geometry and evolution of the reactivated structures. It also acts as an indenter and imposes additional boundary conditions adding to the shortening component in the region and the onset of complex transpressional strain patterns. The geometry and kinematics of the flower structure in the upper crust is mimicked in the ductile mid to lower crust. Upper greenschist facies mylonites reveal a complex fold pattern developed in response to contemporaneous non-coaxial and coaxial deformation. The folding formed during a continuation of deformation associated with mylonitisation at depths within the fault system. The fact that strain localisation and transpressive strain patterns in the brittle crust continue into the ductile zones suggests there is a feedback relationship between the two regimes. The reactivation of pre-existing structures and the influence of rheological factors are considered as first order factors controlling strain partitioning in the plate boundary zone. Recognition of local strain partitioning is important for assessing slip rates and earthquake recurrence. Similarly, the faults extend down below the seismogenic zone so that interaction of the different structures with each other may produce changes in fault behaviour which affects earthquake nucleation. Although the Alpine fault is a major structure in the South Island of New Zealand with over 400 km of dextral movement, the reactivated structures still exert a degree of control locally on the structure and kinematics of the plate boundary zone. Reactivation of inherent fault structures has important implications for the initiation of plate boundary faults and the alteration of the plate boundary geometry with evolving deformation.

APA, Harvard, Vancouver, ISO, and other styles

25

Jiang, Haiyan. "Three essays on ownership concentration in New Zealand." Diss., Lincoln University, 2009. http://hdl.handle.net/10182/974.

Full text

Abstract:

There are two competing theoretical debates about the impact of ownership concentration on organisational outcomes, namely efficient-monitoring hypothesis and conflict-of-interest (strategic-alignment) hypothesis. New Zealand has a distinctively concentrated ownership structure. This raises an important research question: Does concentrated ownership in New Zealand perform an efficient monitoring or opportunistic function? This question remains unanswered due to the very limited research on ownership structure in New Zealand. This research considers three specific where studying the function of ownership concentration is likely to be insightful. Three contexts are: CEO compensation scheme, corporate voluntary disclosures and investor perception of ownership structure in the stock market. This research further contributes to the existing literature by decomposing ownership into four mutually exclusive groups, namely financial institution-, government-, management- and other company-controlled ownership structures. The different impacts of ownership concentration under each type of controlling ownership structure are investigated. The findings of Essay One reveal that concentrated ownership is a significant contributor to the poor CEO compensation pay-for-performance relationship in New Zealand listed companies. However, reduced ownership concentration promotes the alignment between CEO compensation and firm performance. These results imply that large shareholders in New Zealand do not play a monitoring role in curbing managerial power; rather it exacerbates the poor relationship between CEO compensation and firm performance. In Essay Two, regression results show that companies characterised by financial institution-controlled ownership structure tend to make significantly fewer (more) disclosures at high (low) concentration levels. In contrast, firm observations in the high concentration group with government- and management-controlled ownership structures have considerably higher voluntary disclosure scores compared with their low concentration counterparts. With respect to the linearity assumption, the relationship between ownership concentration and voluntary disclosure practices unveil a non-linear pattern, indicating that the efficiency of large shareholders’ monitoring varies with the level of intensity of ownership concentration. The results of Essay Three demonstrate that ownership concentration in general is positively associated with information asymmetry observed around annual report release date. This is supportive of investor-adverse selection towards ownership concentration, and such an adverse selection problem is strongly associated with financial institutional and managerial shareholdings. Also, ownership concentration decreases stock liquidity, so no result is found in line with the ownership concentration liquidity hypothesis. When voluntary disclosure is taken into account, regression results suggest that disclosure significantly attenuates information asymmetry risk related to ownership concentration. This effect is particularly pronounced for firms with management-controlled ownership structure. Findings highlight the importance of corporate disclosures under concentrated ownership structure in eliminating information asymmetry and enhancing market efficiency in New Zealand.

APA, Harvard, Vancouver, ISO, and other styles

26

Harrison, A. J. "Crustal and upper mantle structure of the Taupo Volcanic Zone, New Zealand." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603773.

Full text

Abstract:

The Taupe Volcanic Zone (TVZ) is a major Pliocene-Quaternary NNE-SSW orientated volcano-techonic complex, in central North Island, New Zealand. It is a region characterised by voluminous rhyolitic eruptions, high natural heat flow, intense shallow seismic activity and active NW-SE extension. The central portion of the TVZ is regarded as the most frequently active and productive silicic volcanic system on Earth, yet to date no direct evidence for the source for the magmatisim has been found. In February and December 2001, as part of the NIGHT (North Island GeopHysical Transect) experiment, a total of ten 500 kg land slots were fired into an NW-SE array that ran the width of central North Island, New Zealand. An additional passive array of broad-band and short-period instruments centred on the TVZ recorded local and teleseismic earthquakes for six and a half months. Forward and inverse modelling of this active and shallow (< 10 km) earthquake data shows low-velocity (2.0-3.5 km/s) volcanic sediments reaching a maximum thickness of 3 km beneath the central TVZ. Underlying these sediments to 16 km depth are velocities of 5.0-6.5 km/s, interpreted as quartzo-fieldspathic crust. East and west of the TVZ, these velocities are observed to depths of 30 and 23 km respectively. Beneath the TVZ, material with P-wave velocities of 6.9-7.3 km/s are observed to ~30 km depth and are interpreted as heavily intruded or underplated lower crust. Modelling of deep (> 40 km) earthquake events originating near the top of the subducting Pacific plate, reveals a low-velocity region (LVR) (Vp of 7.4-7.8 km/s) overlying a northwest dipping high-velocity structure that coincides with the Wadati-Benioff zone.

APA, Harvard, Vancouver, ISO, and other styles

27

Crawford, J. A. B. "The role and structure of the New Zealand Volunteer Force 1885-1910." Thesis, University of Canterbury. History, 1986. http://hdl.handle.net/10092/6836.

Full text

Abstract:

In this thesis I propose to examine the role and structure of the New Zealand Volunteer Force between 1885 and 1910; a period beginning with the upsurge of interest in defence matters due to the Russian war scare, and ending with the abolition of the Volunteer system. This has been a largely neglected area of study in New Zealand history, which this thesis goes in same way to redress. I begin by outlining the development of Volunteering in Britain and New Zealand before 1885. The roles of the Volunteer Force in the defence of New Zealand, and in local communities are studied in some detail. A study is also made of the type of men who joined, and some conclusions are reached as to why they became involved in the Movement. Particular attention is devoted to the structure and operation of Volunteer corps. The weaknesses of the Volunteer system are studied in some detail, as are the resultant limitations on the Force's military effectiveness. The composition and activities of the Force over the period are surveyed and related to changes in New Zealand's defence policy and posture. Finally, the nature of the Volunteer Movement is analysed.

APA, Harvard, Vancouver, ISO, and other styles

28

Hampton, Samuel Job. "Growth, Structure and Evolution the Lyttelton Volcanic Complex, Banks Peninsula, New Zealand." Thesis, University of Canterbury. Geological Sciences, 2010. http://hdl.handle.net/10092/4117.

Full text

Abstract:

The Lyttelton Volcanic Complex, north-western Banks Peninsula, New Zealand, is comprised of five overlapping volcanic cones. Two magma systems are postulated to have fed Banks Peninsula’s basaltic intraplate volcanism, with simultaneous volcanism occurring in both the north-western and south-eastern regions of Banks Peninsula, to form Lyttelton and Akaroa Volcanic Complexes respectively. The elongate form of Banks Peninsula is postulated to relate to the upward constraining of magmatism in a north-west / south-east fault bounded zone. The Lyttelton Volcanic Complex resulted from the development of a pull-apart basin, with a number of releasing bend faults, controlling the location of eruptive sites. Cone structure further influenced the pathway magma propagated, with new eruptive sites developing on the un-buttressed flanks, resulting in the eruption and formation of a new cone, or as further cone growth recorded as an eruptive package. Each cone formed through constructional or eruptive phases, termed an eruptive package. Eruptive packages commonly terminate with a rubbly a’a to blocky lava flow, identified through stratigraphic relationships, lava flow trends and flow types, a related dyking regime, and radial erosional features (i.e. ridges and valleys). Within the overall evolving geochemical trend of the Lyttelton Volcanic Complex, are cyclic eruptive phases, intrinsically linked to eruptive packages. Within an eruptive package, crystal content fluctuates, but there is a common trend of increasing feldspar content, with peak levels corresponding to a blocky lava flow horizon, indicating the role of increased crystalinity and lava flow rheology. Cyclic eruptive phases relate to discreet magma batches within the higher levels of the edifice, with crystal content increasing as each magma batch evolves, limiting the ability of the volcanic system, over time, to erupt. Evolving magmas resulted in explosive eruptions following effusive eruptives, and / or result in the intrusion of hypabyssal features such as dykes and domes, of more evolved compositions (i.e. trachyte). Each eruptive package hosts a radial dyke swarm, reflecting the stress state of a shallow level magma chamber or a newly developed stress field due to gravitational relaxation in the newly constructed edifice, at the time of emplacement. Two distinct erosional structures are modelled; radial valleys and cone-controlled valleys. Radial valleys reflect radial erosion about a cone’s summit, while cone-controlled valleys are regions where eruptive packages and cones from different centres meet, allowing stream development. Interbedded epiclastic deposits within the Lyttelton lava flow sequences indicate volcanic degradation during volcanic activity. As degradation of the volcanic complex progressed, summit regions coalesced, later becoming unidirectional breached, increasing the area of the drainage basin and thus the potential to erode and transport extensive amounts of material away, ultimately forming Lyttelton Harbour, Gebbies Pass, and the infilled Mt Herbert region. Epiclastic deposits on the south-eastern side of Lyttelton Harbour indicate a paleo-valley system (paleo-Lyttelton Harbour) existed prior to 8.1 Ma, while the morphology of the Lyttelton Volcanic Complex directed the eruptive sites, style and resultant morphology of the proceeding volcanic groups.

APA, Harvard, Vancouver, ISO, and other styles

29

Ostrow, D. Gigi, and n/a. "Larval dispersal and population genetic structure of brachiopods in the New Zealand fiords." University of Otago. Department of Marine Science, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070308.144342.

Full text

Abstract:

New Zealand�s fourteen deep-water fiords have complex physical and hydrographic features as well as strong environmental gradients, all of which may influence the population structure of organisms that inhabit the fiords. I examined the population structure of the brachiopod Terebratella sanguinea over ecological and evolutionary time scales in relation to physical and hydrographic features of the fiords. To further explore the role of larval dispersal in this system, comparisons between population genetic structure of T. sanguinea and a brachiopod with a contrasting larval dispersal strategy (Liothyrella neozelanica) were made. Aspects of the life history of the articulate brachiopod Terebratella sanguinea were measured. I measured density and size throughout Doubtful Sound and growth at outer (5 km from outer coast) and inner fiord sites (13.5 km from outer coast). Additionally, reproductive periodicity was measured at a single site within Doubtful Sound. Terebratella sanguinea occurred at significantly lower densities and was significantly smaller at the outer fiord site (p < 0.05), however growth rates between an inner and outer fiord site did not differ significantly. Terebratella sanguinea was found to have separate sexes and synchronous maturation of oocytes with spawning occurring in the austral winter. These results indicated that, on an ecological time scale, the environmental gradient of the fiords influences aspects of T. sanguinea population structure. In order to determine the influence of the fiord environment on genetic population structure, patterns among T. sanguinea from across Fiordland were assessed using two genetic markers, and these data were compared to hydrodynamic variables. Ten sites (322 individuals) were included in a preliminary allozyme analysis, and 20 sites (358 individuals) were used for the amplified fragment length polymorphism (AFLP) analysis. Patchy genetic differentiation was revealed with both markers, and a break between Long Sound and the other Fiordland sites was detected with AFLP markers. My results suggest hydrodynamic features of this region may isolate organisms that can disperse only during a planktonic larval phase, however this isolation is visible in genetic patterns only at the most extreme values of the hydrodynamic variables. To better understand how the fiord environment influences population structure of organisms that disperse via planktonic larvae, I compared population genetic structure of two sympatric brachiopod species that differ in planktonic larval duration. Genetic analysis using the AFLP technique revealed population structuring corresponding to the contrasting modes of larval dispersal. AMOVA analysis indicated Liothyrella neozelanica, a brachiopod that broods its larvae, had more limited exchange among sites within a fiord than did T. sanguinea, a brachiopod that does not brood its larvae. In general, the fiord hydrographic conditions may be creating opportunities for local genetic differentiation (for example Long Sound) in organisms capable of longer distance dispersal, but organisms with lower potential for dispersal are more strongly influenced by ontogeny than by hydrography. Understanding the population structure of some of the marine fauna of Fiordland is an important cornerstone for the developing management plan for the area. Conservation of the underwater resources of this World Heritage Area can be successful if the structure of the system and the mechanisms driving this structure are taken into account.

APA, Harvard, Vancouver, ISO, and other styles

30

Harfield, Toby. "Competitive strategies and structures in three New Zealand industries through a postmodern lens." Thesis, University of Canterbury. Management, 1997. http://hdl.handle.net/10092/4499.

Full text

Abstract:

This thesis is a description of an emergent inquiry which extends the methodological, theoretical, and philosophical conventions which have become entrenched within the strategic management literature. The purpose of the research is to use a postmodern sensibility to describe historical events gleaned from first-person accounts in an attempt to present 'insider views' of managing in a de-regulating economy in a globalizing world. The research is located within the New Zealand experiment of economic, political, and social change during the 1980s and 90s. The postmodern sensibility has impacted most clearly in the production of this document. The thesis is an example of alternative forms and structures and contents not usually found within the strategic management literature. A processual, reflexive method is used to construct a sense-making narrative which connects the tales of three journeys; managerial, researcher and academic. Postmodern concerns of 'discourse', 'fragmented identities' and 'research as resistance' are used to link the three forms of knowledge production; managerial, researcher, strategic management. Managers from three New Zealand industries, footwear manufacturing, wine and printing, were interviewed to gain an 'insider view' of firm strategy and industry structure. Although a diversity of issues emerged during the research, I decided that each industry story would privilege one aspect of common threads which I perceived in all of the industries, but which had 'emerged' more strongly in a particular industry during this interpretative research project. The distinct conclusion that strategy is a journey not a destination as suggested in most of the strategic management literature was evident as the footwear manufacturers retreated from volume. Most managers in this study appear to be intent on continuing the journey rather than arriving at a destination. That cooperation and competition are necessary for industry survival in a de-regulating economy was most evident in the wine industry. It is obvious that a gap exists between the strategic management discourse and the practices and values of managers in this study. Cooperation\competition appears more significant than competition for industry survival in this small society. Rather than ONE designated strategy, firms are dedicated to a diversity of generic strategy combinations in order to survive in a globalizing economy. Keeping the strategic journey going by 'sustained adaptation' seemed the intention of most of the managers in this study, but especially those in the printing industries. The creation of flexibility within a competitive\cooperative environment is the imperative of firms and industries in this study.

APA, Harvard, Vancouver, ISO, and other styles

31

Willems, Nancy. "Forest structure and regeneration dynamics of podocarp/hardwood forest fragments, Banks Peninsula, New Zealand." Lincoln University, 1999. http://hdl.handle.net/10182/1301.

Full text

Abstract:

Although species maintenance in small forest fragments relies on successful regeneration and recruitment, few studies have examined the effects of fragmentation on regeneration processes. New Zealand's podocarp species rely on large disturbance openings operating across a vegetated landscape to stimulate regeneration. Clearance of vegetation that results in small fragments of forest removes regeneration opportunities for podocarps by destroying the intact vegetation mosaic, and as a result may exclude disturbances of the scale necessary for podocarp regeneration. Fragmentation alters the disturbance regime of the landscape, with important implications for the regeneration of podocarps on Banks Peninsula. The four remaining lowland podocarp-hardwood fragments on Banks Peninsula were sampled to determine the structure and regeneration patterns of podocarps and to assess their long term viability. Density, basal area, and size and age class distributions were used to examine current composition, and in conjunction with spatial analysis, to identify past regeneration patterns and infer likely future changes in composition and population structure. Podocarp size and age class structures for three of the four fragments were characteristically even-sized and relatively even-aged (eg; Prumnopitys taxifolia c. 350 to 600 years), with little or no regeneration for approximately the last 200 years (old-growth fragments). Regeneration of the current podocarp canopy in the old-growth fragments may have been stimulated by flooding. The fourth younger fragment showed much more recent regeneration with Prumnopitys taxifolia, Podocarpus totara and Dacrycarpus dacrydioides mostly 80-160 years old, and substantial populations of seedlings and saplings, probably as a result of anthropogenic fire. In the absence of major disturbance the podocarp component in forest fragments on Banks Peninsula is likely to decline with composition shifting towards dominance by hardwood species. There is some evidence to suggest that canopy collapse will stimulate some podocarp regeneration within the fragments, however it appears to be unlikely that podocarps will persist on Banks Peninsula indefinitely within the fragments studied. There is an urgent need for more quantitative research in New Zealand fragmentation literature, and a need for more emphasis on processes. Banks Peninsula offers potential for a more landscape scale approach in forest management, and the maintenance of regenerating scrub in pockets about the Peninsula may offer the regeneration opportunities for podocarps that are lacking within protected fragments. My study took a quantitative approach in examining the effects of forest fragmentation on the demographics of podocarps and compositional change in forest fragments on Banks Peninsula.

APA, Harvard, Vancouver, ISO, and other styles

32

Shepstone, Nigel Mark. "A critical examination of electrical engineering curricula across three institutions in New Zealand." Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/2076.

Full text

Abstract:

This thesis examines the effect of the curriculum structure on the pass rate of engineering students in three types of institutions in New Zealand; namely, a polytech, a university of technology, and a university.The pass rate of engineering students has historically been low in all three of these types of institutions. This resulted in the main research question for this study: ‘Is the present engineering curriculum structure in New Zealand the most effective structure in which to prepare engineering graduates for work in the 21st century?’. In order to investigate this question the current curriculum at the above three types of institutions was examined. This examination was undertaken from a number of perspectives. First, the philosophy of an engineering education was determined to establish what exactly an engineering education is. This philosophy was then used to determine which material is legitimate to include in an engineering curriculum and which material should be left out. Second, theories of teaching and learning were examined to determine whether the engineering curriculum is being taught in the most effective way. Third, the theories of curriculum structure and development were studied to determine whether the engineering curriculum is structured in accordance with the latest ideas in curriculum design. Finally, conclusions were drawn about current curriculum structure and whether it complies with modern pedagogical theory.The two main conclusions that were produced by this study are the following: • Engineering curricula are designed with almost no regard for the students that are required to undertake them. This is probably the major reason for the high failure rate. • Understanding in general and engineering understanding in particular are concepts that are not well understood. The result of this is that the teaching, assessing, and curriculum structure for engineering courses are set up using past experience and are not based on any solid foundation. Again, this is an added potential explanation for the high failure rate in engineering.

APA, Harvard, Vancouver, ISO, and other styles

33

Mathewson, Philip Ray. "The evaluation of shore protection structures used for erosion control at Lake Pukaki, New Zealand." Thesis, University of Canterbury. Geography, 2011. http://hdl.handle.net/10092/7152.

Full text

Abstract:

This thesis investigates the shore processes of Lake Pukaki to assess the suitability and performance of existing and potential future options for management of shore hazards. Following two successive raisings of the water level in the past sixty years, Lake Pukaki’s shoreline has undergone extensive erosion. Since mid 1987 until early 1988, shoreline erosion control structures (i.e. rock revetments, gabion baskets and groynes) were constructed and maintained to protect sections of road and other assets from further encroachment of the lake shoreline. The use of the RBR XR-620 pressure sensor in this study marks the first occasion when wave statistics were measured via instrumentation at Lake Pukaki. The mean significant wave height (Hs) identified for this study was 0.53 m, while the maximum recorded wave height was 1.84 m. Similar to other alpine lakes, Lake Pukaki has characteristics of steep plunging waves. The LAKEWAVE wave hindcasting model is used to describe the wave environment about the Lake Pukaki shoreline in terms of its optimum energy potential. The maximum wave height and wave period values estimated by LAKEWAVE have been found to compare well with measured wave statistics. Under the current wave climate, experienced during this study period (July 2010 – February 2011), the majority of the assessed rock revetments seem to be performing well. The Hudson and Van der Meer formula seemed to predict respectable stability thresholds that agree with what was observed in the field. The revetment at Site 3 is the biggest concern in terms of performance based on field observations. The short-period high-magnitude storm events, eventuating from a strong north/northwest wind flow, that coincide with high lake levels tend to cause the most significant erosion along the shoreline at Lake Pukaki and have a major influence of riprap stability. Other environmental factors including the steep nearshore profile, the glacial till backshore, groundwater and precipitation were identified as controlling factors leading to the success or failure of the shore protection structures.

APA, Harvard, Vancouver, ISO, and other styles

34

Billot, Jennie Margaret. "Women's agency in the North Shore and Waitakere cities of Auckland (New Zealand)." Thesis, University of Auckland, 1998. http://wwwlib.umi.com/dissertations/fullcit/9908064.

Full text

Abstract:

This thesis examines the ways in which women assess and seek resources in their urban contexts. I argue that the struggles of daily life in local communities and institutional groups can produce ideological spaces into which new practices, arising from increased consciousness of issues, can be developed. My aim has been to uncover women's experiences in a way that not only interprets meanings from their practices, but also encourages such practices to be seen as valid renderings of women's understandings. I examine women's initiatives through the analysis of varying contexts. While I acknowledge the historical importance of the domestic situation as a threshold for much historic activism, women's proactivity requires a broader situational analysis. I therefore present cases of proactivity within the domestic, public and business spheres, within the two cities of Waitakere and North Shore of Auckland, New Zealand. Through the search for new progressive social identities, women's activities at the inter-personal level are a prime source of social change. It is through the recursive relationship between women as agents and the social structure, that changing interpretations of social expectations are produced, allowing for creative activism. While women's initiatives may aim to transform particular social environments, they become part of the incremental process of change that alters the experience and structure of women's lives. The thesis has four parts. The first outlines the scope, objectives and theoretical framework, while the second conceptualises women's agency and its positioning within social gendered structures. Part Three presents the investigative processes linking the theoretical framework and the empirical analysis. Part Four submits the thematic interpretations of the thesis, concluding that women can be agents of social change in a diversity of ways. I acknowledge my feminist stance, one with layerings of objectives and motivations. I view women's circumstances as resulting from the interweaving of structural forces and personal capacities. The resulting awareness of women's experiences can challenge the values and concepts of masculine discourses. This is viewed through the concept of multiplicity. On a political level this means creating a resistance to hierarchies and a commitment to a plurality of voice, style and structure.
Subscription resource available via Digital Dissertations only.

APA, Harvard, Vancouver, ISO, and other styles

35

Cowan, Hugh Allister. "Structure, seismicity and tectonics of the Porter's Pass-Amberley fault zone, North Canterbury, New Zealand." Thesis, University of Canterbury. Geology, 1992. http://hdl.handle.net/10092/4703.

Full text

Abstract:

The Porter's Pass-Amberley Fault Zone (PPAFZ) is a complex zone of anastomosing faults and folds bounding the south-eastern edge of the transition from subducting Pacific Plate to continental collision on the Australia Plate boundary. This study combines mapping of a 2000 km2 zone from the Southern Alps northeast to the coast near Amberley, 40 km north of metropolitan Christchurch, with an analysis of seismicity and a revision of regional seismic hazard. Three structural styles: 1) a western strike-slip, and 2) a more easterly thrust and reverse domain, pass into 3) a northwest verging fold belt on the northern Canterbury Plains, reflecting the structural levels exposed and the evolving west to east propagation. Basal remnants of a Late Cretaceous-Cenozoic, largely marine sedimentary cover sequence are preserved as outliers that unconformably overlie Mesozoic basement (greywacke and argillite of the Torlesse terrain) in the mountains of the PPAFZ and are underlain by a deeply leached zone which is widely preserved. Structure contouring of the unconformity surface indicates maximum, differential uplift of c.2600 m in the southwest, decreasing to c.1200 m in the coastal fold belt to the northeast. Much lower rates (or reversal) of uplift are evident a few kilometres southeast of the PPAFZ range-front escarpment. The youngest elements of the cover sequence are basement-derived conglomerates of Plio-Pleistocene age preserved on the SE margin. The source is more distant than the intervening mountains of the PPAFZ, probably from the Southern Alps, to the west and northwest. The absence of another regional unconformity on Mesozoic basement, older than Pleistocene, indicates that this uplift is post-Pliocene. Late Pleistocene(<100 kyr) differential uplift rates of c.0.5-2.7 m/kyr from uplifted marine terraces at the east coast, and rates of 2.5-3.3 m/kyr for tectonically-induced river-down cutting further west, suggest that uplift commenced locally during the last 1 Ma, and possibly within the last 0.5 Ma, if average rates are assumed to be uniform over time. Analysis of seismicity, recorded during a 10 week regional survey of micro earthquakes in 1990, identified two seismic zones beneath North Canterbury: 1) a sub-horizontal zone of activity restricted to the upper crust (≤12 km); and 2) a seismic zone in the lower crust (below a ceiling of ≤17 km), that broadens vertically to the north and northwest to a depth of c.40 km, with a bottom edge which dips 10°N and 15°NW, respectively. No events were recorded at depths between 12 km and 17 km, which is interpreted as a relatively aseismic, mid-crustal ductile layer. Marked differences (up to 60°) in the trend of strain axes for events above and below the inferred ductile layer are observed only north of the PPAFZ. A fundamental, north-to-south increase in the Wave-length of major geological structures occurs across the PPAFZ, and is interpreted as evidence that the upper crust beneath the Canterbury Plains is coupled to the lower crust, whereas the upper crust further north is not. Most of the recorded micro earthquakes <12 km deep beneath the PPAFZ have strike-slip mechanisms. It is probable that faults splay upward into the thrusts and folds at the surface as an evolving transpression zone in response to deep shear in basement. There have been no historic surface ruptures of the PPAFZ, but the zone has been characterised historically by frequent small earthquakes. Paleoseismic data (dated landslides and surface ruptures) compiled in this study, indicate a return period of 1500-1900 years between the last two M>7-7.5 earthquakes, and 500-700 years have elapsed since the last. The magnitudes of these events are estimated at c.M7.5, which represents a probable maximum magnitude for the PPAFZ. There are insufficient data to determine whether or not the frequency of large earthquakes conforms to a recognised model of behaviour, but comparison of the paleoseismic data with the historic record of smaller earthquakes, suggests that the magnitudes of the largest earthquakes in this zone are not exponentially distributed. A seismicity model for the PPAFZ (Elder et al., 1991) is reviewed, and a b-value of 1.0 is found to be consistent with the newly acquired paleoseismic data. This b-value reduces the predicted frequency of large earthquakes (M≥7.0) in this zone by a factor of 3.5, while retaining a conservative margin that allows for temporal variations in the frequency of large events and the possibility that the geological database is incomplete, suggesting grounds for revising the hazard model for Christchurch.

APA, Harvard, Vancouver, ISO, and other styles

36

Styles, Kirsten Elisabeth. "Shear wave attenuation structure and anisotropy in the Hikurangi subduction zone, central North Island, New Zealand." Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507045.

Full text

Abstract:

The seismic attenuation structure of a subduction zone can constrain variations in temperature, composition and fluids. Amplitude spectra of 2206 local earthquakes, recorded by a dense network of 116 seismic stations in central North Island (NI), New Zealand, are modelled to image the three-dimensional (3D) shear attenuation structure of the Hikurangi subduction zone, down to 100km. Shear attenuation images are obtained by inverting 22260 t* observations for Qs (the quality factor of S waves) using a previously determined seismic velocity model. A frequency dependence of Q s is applied below 10 Hz, by parameterising t* as tol-ex where to is t* at 1 Hz, I is frequency and a = 0.3. Qs is frequency-independent above 10Hz. The 3D Qs images are interpreted alongside previously determined 3D Qp and Vp/Vs images, providing further constraints on features associated with subduction and magmatism in the Hikurangi subduction zone. The subducted slab is a prominent feature, exhibiting Qs = 1000, consistent with a 120Myr old slab. The upper surface of the slab is lined with hydrous fluids from 10km to > 100 km depth, derived from the dehydration of subducted sediments and hydrated oceanic crust. Between 50 and 75 km depth, the hydrous blanket lining the slab extends 20 km into the mantle wedge, and is imaged as having moderately low Qs ~ 300. The mantle wedge beneath the rhyolite-dominated, central segment of the Taupo Volcanic Zone (TVZ) is highly attenuating, with Qs < Qp and Qp < 100. This region is anomalously hot (> 1400øC) and is responsible for the large extent of melting and high rate of melt production observed in the TVZ. Along-strike to the southwest, the hydrous blanket lining the slab ceases abruptly at a trench-perpendicular plane coincident with the southernmost point of the TVZ, as does a very low Qs (~ 50) region in the forearc crust (0-25 km depth). The cessation correlates with geodetic data. These fluid-rich regions reduce friction at the interface of the two plates and permit low-resistance subduction. Southwest of the trench-perpendicular plane, hydrous fluids are absent and the plates are locked. The seismic anisotropic structure of a subduction zone is a consequence of strain and flow in the mantle, and stress and deformation in the crust. In order to refine interpretations of crustal and upper mantle structure in the Hikurangi subduction zone, anisotropy is mapped by analysing shear wave splitting (SWS) of 773 local earthquakes recorded at 29 seismic stations (3371 station-event pairs). SWS results are interpreted in the context of previous anisotropy studies that used local, regional and teleseismic events, alongside 3D Qs, Qp and Vp/Vs structures. In eastern NI, fast directions are trench-parallel, following the trends of major faults in the axial ranges. The observed 3.7% anisotropy is crustal and results from the alignment of cracks and rock fabric in NI crust, 'perpendicular to the direction of maximum horizontal stress. In southern TVZ, fast directions are NE-SW, NW-SE and N-S, consistent with the alignment of highly-fractured crustal structures associated with rifting in discrete rift segments and intruding dikes. Anisotropy beneath the TVZ is larger (>5%) and is entirely crustal. In western NI, fast directions are predominantly N-S, following the trend of major tectonic features west of the TVZ (e.g., the Hauraki Rift and Coromandel Peninsula). There, anisotropy is small ®2%), crustal and results from the alignment of crustal fabric with trends in regional deformation.

APA, Harvard, Vancouver, ISO, and other styles

37

Kinnison, M. T. "Life history divergence and population structure of New Zealand chinook salmon : a study of contemporary microevolution /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/5316.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Lee, Joo-Seok. "Why do Asian immigrants become entrepreneurs? The case of Korean self-employed immigrants in New Zealand." Click here to access this resource online, 2008. http://hdl.handle.net/10292/445.

Full text

Abstract:

With the number of Asian immigrants continually increasing in New Zealand society, Asian immigrant businesses have been appearing more rapidly in New Zealand, particularly in Auckland. The primary purpose of this study is to enquire into why a certain Asian immigrant group become business people after migrating to Auckland, New Zealand. In addition, it investigates the level of their business activity and the level of happiness with their new life in New Zealand. This study examines the growing phenomenon of Asian immigrants, and the entrepreneurship rate of ethnic groups through existing statistics. The study focuses on Korean immigrants. Twenty self-employed Koreans who are running a business in Auckland participated in the study. They were invited to talk about why they became self-employed business people and related matters about their business activity. The study found that Korean immigrants chose self-employment as a means of getting a job. They gave up seeking mainstream employment opportunities due to the language barrier and their inability to cope with a new society and new system. Other fundamental factors in their decision to become entrepreneurs were that firstly, they were willing to invest a considerable amount of their own money and secondly, they preferred to participate in the workforce rather than to depend on the New Zealand welfare system. Based on the information acquired through the research, the study reported that the recently increased numbers of Asian businesses are partly attributable to New Zealand business immigration policy which introduced a new business category – Long Term Business Visa (LTBV). The findings from this research pointed to commitment that immigrant businesses contribute to the New Zealand economy and New Zealand society as taxpayers and potential employers.

APA, Harvard, Vancouver, ISO, and other styles

39

Carpenter, Vicki Marie. "Beyond responsiveness to community: Democratic voice and the creation of an>education alternative (New Zealand)." Thesis, University of Auckland, 2000. http://wwwlib.umi.com/dissertations/fullcit/9979146.

Full text

Abstract:

This thesis examines how, in a rural New Zealand ‘area school’, successful democratic parental and community voice was able to bring about the creation of an education alternative. While the parental initiative was in line with the rhetoric of Tomorrow' s Schools (1988) the contention in this thesis is that initiatives such as this were not intended by the legislation. Despite the fact that the initiative was stimulated by and explicitly invoked the rhetoric, the spirit of the legislation was philosophically opposed to this particular kind of innovation. The ‘Kiwi’ initiative emerged in 1993, five years after the legislation. The initiative centred around a request for an alternative education programme to be set up within ‘Takiwa School’. This alternative was modelled on Playcentre, a New Zealand Early Childhood Education model, which encompasses aspects of progressivism. Kiwi parents and Takiwa School personnel achieved a ‘school within the school’ for a segment of Takiwa community. Parents became fully involved in all aspects of their children's curriculum, from planning, through to delivery and assessment. This thesis examines the politics of the change process within Takiwa School. Three questions are central to this case study examination of change. These are: What were the parents asking for? How were the parents able to achieve what they were asking for? and What were the effects of the process on what it was that the initiative ultimately became? These three questions are examined in a sociological manner, from a critical realist approach. A range of theoretical tools are utilised; the central theoretical windows are a combination of Exit, Voice and Loyalty-which is provided by Hirschman (1970)-and the theories which are encompassed in the New Institutionalist approach. The central argument of the thesis is that it was a particular combination of conditions and motivations which made the Kiwi innovation possible. The possible replicability of the initiative is discussed. A key concern of the thesis as a whole is whether the set of circumstances in which the innovation transpired was unique.
Subscription resource available via Digital Dissertations only.

APA, Harvard, Vancouver, ISO, and other styles

40

Javernick, Luke Anthony. "Modeling flood-induced processes causing Russell lupin mortality in the braided Ahuriri River, New Zealand." Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2013. http://hdl.handle.net/10092/8972.

Full text

Abstract:

The braided rivers and floodplains in the Upper Waitaki Basin (UWB) of the South Island of New Zealand are critical habitats for endangered and threatened fauna such as the black stilt. However, this habitat has degraded due to introduced predators, hydropower operations, and invasive weeds including Russell lupins. While conservation efforts have been made to restore these habitats, flood events may provide a natural mechanism for removal of invasive vegetation and re-creation of natural floodplain habitats. However, little is understood about the hydraulic effects of floods on vegetation and potential mortality in these dynamic systems. Therefore, this thesis analyzed the flood-induced processes that cause lupin mortality in a reach of the Ahuriri River in the UWB, and simulated various sized flood events to assess how and where these processes occurred. To determine the processes that cause lupin mortality, post-flood observations were utilized to develop the hypothesis that flood-induced drag, erosion, sediment deposition, inundation, and trauma were responsible. Field and laboratory experiments were conducted to evaluate and quantify these individual processes, and results showed that drag, erosion, sediment deposition and inundation could cause lupin mortality. Utilizing these mortality processes, mortality thresholds of velocity, water depth, inundation duration, and morphologic changes were estimated through data analysis and evaluation of various empirical relationships. Delft3D was the numerical model used to simulate 2-dimensional flood hydraulics in the study-reach and was calibrated in three stages for hydraulics, vegetation, and morphology. Hydraulic calibration was achieved using the study-reach topography captured by Structure-from-Motion (SfM) and various hydraulic data (depth, velocity, and water extent from aerial photographs). Vegetation inclusion in Delft3D was possible utilizing a function called ‘trachytopes’, which represented vegetation roughness and flow resistance and was calibrated utilizing data from a lupin-altered flow conveyance experiment. Morphologic calibration was achieved by simulating an observed near-mean annual flood event (209 m3 s-1) and adjusting the model parameters until the simulated morphologic changes best represented the observed morphologic changes captured by pre- and post-flood SfM digital elevation models. Calibration results showed that hydraulics were well represented, vegetation inclusion often improved the simulated water inundation extent accuracy at high flows, but that local erosion and sediment deposition were difficult to replicate. Simulation of morphological change was expected to be limited due to simplistic bank erosion prediction methods. Nevertheless, the model was considered adequate since simulated total bank erosion was comparable to that observed and realistic river characteristics (riffles, pools, and channel width) were produced. Flood events ranging from the 2- to 500-year flood were simulated with the calibrated model, and lupin mortality was estimated using simulation results with the lupin mortality thresholds. Results showed that various degrees of lupin mortality occurred for the different flood events, but that the dominant mortality processes fluctuated between erosion, drag, and inundation. Sediment deposition-induced mortality was minimal, but was likely under-represented in the modeling due to poor model sediment deposition replication and possibly over-restrictive deposition mortality thresholds. The research presented in this thesis provided greater understanding of how natural flood events restore and preserve the floodplain habitats of the UWB and can be used to aid current and future braided river conservation and restoration efforts.

APA, Harvard, Vancouver, ISO, and other styles

41

Dempsey, Edward Damien. "The kinematics, rheology, structure and anisotropy of the Alpine schist derived Alpine fault zone mylonites, New Zealand." Thesis, University of Liverpool, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539562.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Jongens, Richard. "The Anatoki fault and structure of the adjacent Buller and Takaka terrane rocks, northwest Nelson, New Zealand." Thesis, University of Canterbury. Geology, 1997. http://hdl.handle.net/10092/4758.

Full text

Abstract:

The Early Paleozoic rocks exposed in the northwest of the South Island, New Zealand, can be grouped into two terranes. An Ordovician deep water passive margin assemblage makes up the Buller terrane. A Cambrian arc assemblage and an Ordovician to Silurian mainly shallow water passive margin assemblage make up the Takaka terrane. The two terranes are cut by Late Paleozoic and Early Cretaceous plutonic rocks. The terrane boundary is the Anatoki Fault, which is a north-south striking, east dipping structure that steepens southwards. This thesis is a study of the movement history of the Anatoki Fault and a study of structures and microstructures in the flanking lithologies of the Buller and Takaka terranes. The study area is divided into seven areal domains, each containing structural evidence that can be related on an inter-domainal scale. In the study area, three major deformation events can be recognised in both the Buller and Takaka terrane rocks. Each consecutive deformation event recognised in one of the terranes has structures that can be matched in style, orientation, and timing of development with that in the adjacent terrane. D, is represented by upright to overturned towards the west, N-S trending, large scale folds with an axial planar slaty cleavage. D, structures are observed in all domains and relate to other N-S trending structures seen in both terranes. Based principally on constraints outside the study area, D, is thought to be Early-Middle Devonian in age. A well-developed foliation, which obliterates D, structures in close to the Anatoki Fault, represents D2• The foliation expresses a zone of non-coaxial ductile deformation observed in the north of the study area. Rb-Sr geochronology, and the relationship between the foliation and the adjacent ~lllMa Mt Olympus Pluton, suggest D2 formed in the Early Cretaceous (soon after ~ IllMa). D3 is represented mainly by mesoscale folds with an axial planar crenulation cleavage. D3 structures crenulate and refold both D, and D2 structures and are mid-Cretaceous in age. Two deformations are recognised in the Balloon Melange of the Takaka terrane. The first deformation is responsible for the melanging when the protolith was in an unlithified state. This deformation occurred in the Late Cambrian. The second deformation is expressed by a slaty fabric when the melange was lithified and is thought to be related to D,. The contact between the Balloon Melange and other units in the Takaka terrane is thought to be tectonic but locally intrusive. Most structures in Northwest Nelson can be correlated with D" D2, and D3 of the study area. However, some N-S trending folds in the Cambrian arc assemblage are thought to be older than D, and are here thought to relate to pre-D, Late Cambrian deformation recognised in the Balloon Melange. The Anatoki Fault records a complex history of both ductile and brittle movement, a history which differs in various segments of the fault. Thus, tectonites from central segments of the study area record ductile east over west reverse-slip associated with D" and represent an early stage in its movement history; D2 tectonites from the northernmost studied segment record Early Cretaceous ductile dextral-slip reactivation; tectonites from the southernmost segment records ductilelbrittle dextral normal-slip reactivation that postdates the intrusion of the ~137Ma Crow Granite. The post-137Ma movement, and brittle/ductile movement of unknown age recorded in the remaining segments, may be related to D2• The Anatoki Fault has also undergone Late Cenozoic brittle reactivation. A plate tectonic model is developed to explain the earlier structures of the study area and the general structure of Northwest Nelson. It is proposed that an accretionary wedge/fore-arc setting related to a Cambrian island arc subduction zone provides the environment in which pre-D, structures formed, and that in the Early-Middle Devonian, the two terranes amalgamated as a result of a convergent strike-slip plate boundary. Much of the Takaka terrane was truncated by the strike-slip movement which dominated the early stages of Devonian deformation whereas convergence related thin-skinned tectonics dominated the latter stages of deformation, and resulted in formation of the D, structures. In this model, the Central Belt of the Takaka terrane, which consists primarily of the Cambrian arc assemblage, is interpreted as an uplifted tectonic wedge in which the Anatoki Fault is a back-thrust. D2 and D3 relate to an extremely active and changing tectonic period of New Zealand in the Early to mid-Cretaceous. Twinning in ankerite porphyroblasts in D2 tectonites was examined to investigate the twin laws and their usefulness as a paleostress indicator. Results show that the twin laws are the same as those in dolomite and that twinning occurs at temperatures above ~250°C. Paleostress axes derived from the analysis provide evidence of microscale strain partitioning in which the porphyroblasts have accommodated a pure shear component. The c-axes preferred orientations in dynamically recrystallised calcite tectonites, from the Anatoki Fault zone, most closely resemble those produced in the grain-boundary migration regime of experimental studies. As such, the preferred orientations cannot be used to indicate shear-sense.

APA, Harvard, Vancouver, ISO, and other styles

43

Toy, Virginia Gail, and n/a. "Rheology of the Alpine Fault Mylonite Zone : deformation processes at and below the base of the seismogenic zone in a major plate boundary structure." University of Otago. Department of Geology, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080305.110949.

Full text

Abstract:

The Alpine Fault is the major structure of the Pacific-Australian plate boundary through New Zealand�s South Island. During dextral reverse fault slip, a <5 million year old, ~1 km thick mylonite zone has been exhumed in the hanging-wall, providing unique exposure of material deformed to very high strains at deep crustal levels under boundary conditions constrained by present-day plate motions. The purpose of this study was to investigate the fault zone rheology and mechanisms of strain localisation, to obtain further information about how the structural development of this shear zone relates to the kinematic and thermal boundary constraints, and to investigate the mechanisms by which the viscously deforming mylonite zone is linked to the brittle structure, that fails episodically causing large earthquakes. This study has focussed on the central section of the fault from Harihari to Fox Glacier. In this area, mylonites derived from a quartzofeldspathic Alpine Schist protolith are most common, but slivers of Western Province-derived footwall material, which can be differentiated using mineralogy and bulk rock geochemistry, were also incorporated into the fault zone. These footwall-derived mylonites are increasingly common towards the north. At amphibolite-facies conditions mylonitic deformation was localised to the mylonite and ultramylonite subzones of the schist-derived mylonites. Most deformation was accommodated by dislocation creep of quartz, which developed strong Y-maximum crystallographic preferred orientation (CPO) patterns by prism (a) dominant slip. Formation of this highly-oriented fabric would have led to significant geometric softening and enhanced strain localisation. During this high strain deformation, pre-existing Alpine Schist fabrics in polyphase rocks were reconstituted to relatively well-mixed, finer-grained aggregates. As a result of this fabric homogenisation, strong syn-mylonitic object lineations were not formed. Strain models show that weak lineations trending towards ~090� and kinematic directions indicated by asymmetric fabrics and CPO pattern symmetry could have formed during pure shear stretches up-dip of the fault of ~3.5, coupled with simple shear strains [greater than or equal to]30. The preferred estimate of simple:pure shear strain gives a kinematc vorticity number, W[k] [greater than or equal to]̲ 0.9997. Rapid exhumation due to fault slip resulted in advection of crustal isotherms. New thermobarometric and fluid inclusion analyses from fault zone materials allow the thermal gradient along an uplift path in the fault rocks to be more precisely defined than previously. Fluid inclusion data indicate temperatures of 325+̲15�C were experienced at depths of ~45 km, so that a high thermal gradient of ~75�C km⁻� is indicated in the near-surface. This gradient must fall off to [ less than approximately]l0�C km⁻� below the brittle-viscous transition since feldspar thermobarometry, Ti-inbiotite thermometry and the absence of prism(c)-slip quartz CPO fabrics indicate deformation temperatures did not exceed ~ 650�C at [greater than or equal to] 7.0-8.5�1.5 kbar, ie. 26-33 km depth. During exhumation, the strongly oriented quartzite fabrics were not favourably oriented for activation of the lower temperature basal(a) slip system, which should have dominated at depths [less than approximately]20 km. Quartz continued to deform by crystal-plastic mechanisms to shallow levels. However, pure dislocation creep of quartz was replaced by a frictional-viscous deformation mechanism of sliding on weak mica basal planes coupled with dislocation creep of quartz. Such frictional-viscous flow is particularly favoured during high-strain rate events as might be expected during rupture of the overlying brittle fault zone. Maximum flow stresses supported by this mechanism are ~65 Mpa, similar to those indicated by recrystallised grain size paleopiezometry of quartz (D>25[mu]m, indicating [Delta][sigma][max] ~55 MPa for most mylonites). It is likely that the preferentially oriented prism (a) slip system was activated during these events, so the Y-maximum CPO fabrics were preserved. Simple numerical models show that activation of this slip system is favoured over the basal (a) system, which has a lower critical resolved shear stress (CRSS) at low temperatures, for aggregates with strong Y-maximum orientations. Absence of pervasive crystal-plastic deformation of micas and feldspars during activation of this mechanism also resulted in preservation of mineral chemistries from the highest grades of mylonitic deformation (ie. amphibolite-facies). Retrograde, epidote-amphibolite to greenschist-facies mineral assemblages were pervasively developed in ultramylonites and cataclasites immediately adjacent to the fault core and in footwall-derived mylonites, perhaps during episodic transfer of this material into and subsequently out of the cooler footwall block. In the more distal protomylonites, retrograde assemblages were locally developed along shear bands that also accommodated most of the mylonitic deformation in these rocks. Ti-in-biotite thermometry suggests biotite in these shear bands equilibrated down to ~500+̲50�C, suggesting crystal-plastic deformation of this mineral continued to these temperatures. Crossed-girdle quartz CPO fabrics were formed in these protomylonites by basal (a) dominant slip, indicating a strongly oriented fabric had not previously formed at depth due to the relatively small strains, and that dislocation creep of quartz continued at depths [less than or equal to]20 km. Lineation orientations, CPO fabric symmetry and shear-band fabrics in these protomylonites are consistent with a smaller simple:pure shear strain ratio than that observed closer to the fault core (W[k] [greater than approximately] 0.98), but require a similar total pure shear component. Furthermore, they indicate an increase in the simple shear component with time, consistent with incorporation of new hanging-wall material into the fault zone. Pre-existing lineations were only slowly rotated into coincidence with the mylonitic simple shear direction in the shear bands since they lay close to the simple shear plane, and inherited orientations were not destroyed until large finite strains (<100) were achieved. As the fault rocks were exhumed through the brittle-viscous transition, they experienced localised brittle shear failures. These small-scale seismic events formed friction melts (ie. pseudotachylytes). The volume of pseudotachylyte produced is related to host rock mineralogy (more melt in host rocks containing hydrated minerals), and fabric (more melt in isotropic host rocks). Frictional melting also occurred within cataclastic hosts, indicating the cataclasites around the principal slip surface of the Alpine Fault were produced by multiple episodes of discrete shear rather than distributed cataclastic flow. Pseudotachylytes were also formed in the presence of fluids, suggesting relatively high fault gouge permeabilities were transiently attained, probably during large earthquakes. Frictional melting contributed to formation of phyllosilicate-rich fault gouges, weakening the brittle structure and promoting slip localisation. The location of faulting and pseudotachylyte formation, and the strength of the fault in the brittle regime were strongly influenced by cyclic hydrothermal cementation processes. A thermomechanical model of the central Alpine Fault zone has been defined using the results of this study. The mylonites represent a localised zone of high simple shear strain, embedded in a crustal block that underwent bulk pure shear. The boundaries of the simple shear zone moved into the surrounding material with time. This means that the exhumed sequence does not represent a simple 'time slice' illustrating progressive fault rock development during increasing simple shear strains. The deformation history of the mylonites at deep crustal P-T conditions had a profound influence on subsequent deformation mechanisms and fabric development during exhumation.

APA, Harvard, Vancouver, ISO, and other styles

44

Harrison, Ian Stewart. "The structure of the Buller terrane west of the Anatoki thrust, upper Cobb Valley, Northwest Nelson, New Zealand." Thesis, University of Canterbury. Department of Geology, 1993. http://hdl.handle.net/10092/3919.

Full text

Abstract:

The Buller terrane west of the Anatoki Thrust in the upper Cobb Valley area is composed of Ordovician marine sediments. Rocks in the field area are divided into two domains of different structural styles. In the west Domain 1 includes the Roaring Lion Formation which displays a series of mesoscopic gently plunging upright folds on the limb of a single megascopic fold. Folding is associated with low greenschist facies metamorphism. Domain 2 comprises rocks of the Aorangi Mine, Leslie, Douglas and Peel Formations; which contain three cleavage sets. The last cleavage is associated with a reclined fold in the east of Domain 2, which is correlated with folding at Gouland Downs to the north. Domain one was brought into contact with Domain two by thrusting and strike slip movement along the Fenella Fault Zone, a steeply dipping zone of bedding concordant faulting. Geochemistry shows the Roaring Lion Formation is very similar to the Greenland Group of Westland, the small differences shown by the Roaring Lion Formation are because it is slightly richer in quartz. Analysis of calcite fabrics from deformed Mount Patriarch Formation limestone which occurs as a fault sliver in the Anatoki Thrust Zone, indicates the last movement on the Anatoki "Thrust" was normal.

APA, Harvard, Vancouver, ISO, and other styles

45

Titulaer, William A. "Respiration physiology and the gill structure of the New Zealand freshwater crayfish Paranephrops zealandicus (White 1847) (Decapoda: Parastacidae)." Thesis, University of Canterbury. Zoology, 1995. http://hdl.handle.net/10092/5955.

Full text

Abstract:

The New Zealand freshwater crayfish P. zealandicus emerges from water and exposes it's respiratory surface to desiccation and collapse, it's haemolymph to acid-base disturbance and it's tissues to hypoxia. This study was to investigate the respiratory system during aerial respiration. P. zealandicus has 20 gills, a rudimentary gill and an epipodite (20 + r + ep). Two types of gill filament were identified; a respiratory filament with a cuticle 0.7µm thick, an afferent and efferent vessel and haemolymph lacunae adjacent to the cuticle, and an ion regulating filament with a cuticle 1.2µm thick in which the cells adjacent to the cuticle contain all the organelles and membranes which are associated with ion regulating tissues. It was found that P. zealandicus emerged from the water voluntarily. There was no significant difference in the frequency of emersion by solo crayfish at 18°C, crayfish pairs at 18°C, solo crayfish experiencing hypoxia at l8°C, and solo crayfish at 24°C. Solo crayfish and crayfish pairs recorded a significantly higher level of emersion activity at night than during the daytime. At 15°C the settled rate of oxygen consumption in air, 1.03± 0.03 µmol.g-1 .h-1 (± 1 sem), was not significantly different from the settled rate of oxygen consumption in water, 1.10± 0.03 µmol. g-1. h-1. Oxygen consumption in water was compromised by declining external oxygen tension below PCR1T (41 - 44 Torr). At PCR1T the oxygen consumption was 1.06 ± 0.05 /lffi01.g-1 .h-1 At only one time in 48 hours aerial respiration was haemo1ymph arterial oxygen tension below PCRIT .This was after 12 hours aerial respiration, and was associated with an increase in lactate concentration to 5 mmol.1-1 , which was, however, removed during the subsequent 12 hours aerial respiration. The crayfish were not considered to be experiencing internal hypoxia for the remainder of the 48 hours in air. The total oxygen consumed during 8 hours recovering from aerial respiration was similar to the total oxygen consumed during the 8 hours settling at the beginning of the experiment, indicating no measurable oxygen debt accumulated during 48 hours aerial respiration. After emersion into air the crayfish experienced a respiratory acidosis, and an elevated arterial carbon-dioxide tension. Total haemolymph carbonates, measured 12 hours after emerging from water indicated compensation by metabolic alkalosis. Upon returning to the water the crayfish experienced a respiratory alkalosis. Rapidly declining arterial carbon-dioxide tension, and total haemolymph carbonates indicated compensation by metabolic acidosis. The measured in vitro non-bicarbonate buffer capacity was -3.8 mmol.-1 . (pH unit)-1. During the 48 hours in air the pH was regulated between 7.55 and 7.68 with the pH significantly more alkaline at 8 pm than at 8 am, by 0.1 pH units. At 15°C, the solubility of oxygen in haemolymph, ±PLASMAO2, was 1.8 µmol.1-1.Torr-1, and at an oxygen tension of 150 Torr the total haemolymph oxygen content was 1 mmol.1-1. There was a Bohr effect, ΔlogP50/ΔpH, of - 0.48 to - ,0.96. Settled in water at 15°C, with a haemolymph carbon-dioxide tension of 2.6 Torr, the crayfish haemocyanin was 50 % saturated at an oxygen tension of 12 Torr. Crayfish kept at 15°C had an oxygen content when the haemocyanin was 50 % saturated, and a total oxygen content, which were 50 % higher than crayfish from water at 9.5°C. Estimates of limitation to diffusion/perfusion, Ldiff, in water of 0.76, and in air of 0.98, indicate that respiration in P. zealandicus is diffusion limited. The respiratory frequency, fR, and heart frequency, fH, of settled crayfish in air was not significantly different from settled crayfish in water. The fH during aerial respiration demonstrated less fluctuation than fH in control crayfish in water, and the fR of crayfish in air was more variable than the fR in control crayfish in water. The control crayfish settled in water exhibited a significant diel fluctuation in fR and fH, with high fR and fH recorded in the evening and low fR and fH in the morning. Several activities and changes measured in this study have a diel rhythm. A dusk pH recorded at 8 pm. was 0.1 pH units more alkaline than a dawn pH recorded at 8 am. Settled in water, P. zealandicus exhibits a diel fluctuation in fR and fH, with high fR and fH recorded in the evening and low fR and fH in the morning. At 18°C, solitary crayfish and crayfish pairs show higher levels of emersion activity at night than during the daytime. The results indicate that crayfish P. zealandicus has a respiratory system which can cope with aerial respiration, and some of the activities and changes reported in this study have a diel rhythm.

APA, Harvard, Vancouver, ISO, and other styles

46

Mauger, Stanley Philip. "The significance of knowledge of social contexts to concept development in graphic design practice in New Zealand." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1312.

Full text

Abstract:

This thesis investigates the question; what is the significance that a cross-section of New Zealand graphic designers placed on using knowledge of social contexts to inform their practice? It reveals whether graphic designers in the research, drew on knowledge of social contexts that arose from implicit knowledge, whether they relied on dedicated research to locate knowledge of social contexts and the extent to which that knowledge of social contexts was significant to their practice.The theoretical framework for the research was primarily based on Pierre Bourdieu’s concepts of habitus, social structure and practice, to find the degree to which knowledge of social contexts came out of either a conscious process of enhancing cultural capital in designers’ day-to-day practice, or from dispositions inculcated over designers’ lifetimes through habitus at various levels. Bourdieu’s sociological perspectives are particularly applicable to this research, because of the way in which he places great emphasis on cultural knowledge as the basis of cultural investigation.The ethnographic research modelled on Bourdieu’s methods, in which empirical studies are essential to theoretical research, used conversation analysis in which the reflexivity of the interviewer contributed strongly to the collection of data. The research method was based on a series of seven case studies conducted with New Zealand graphic designers of varying backgrounds and working situations, between 2002 and 2003. The research investigated how they had acquired knowledge of social contexts for practice and the importance that they placed on bringing this knowledge into their practice. The research group ranged from recent graduates to senior and accomplished graphic designers.Graphic designers showed the significance of knowing about social contexts, through the cultural capital that was important to their practice and to their positions in the graphic design field. This research has highlighted the difficulty that designers encountered, to varying degrees, in identifying how knowledge of social contexts came into their practice or even how they had acquired this knowledge.Knowledge of social contexts was shown to be derived from designers’ own social structures and the durable dispositions and practice relative to their background, from the habitus of the internal culture of a designer's firm, from within the wider field of graphic design practice and the changing dispositions arising from it and finally, from graphic designers’ external social worlds. This research suggests that contextual knowledge also needs to be brought into the teaching of graphic design, rather than being seen to arise implicitly in conceptualisation and studio practice.

APA, Harvard, Vancouver, ISO, and other styles

47

Scrivin, Nicholas. "'The Bobby Calf' - non linear and non classical narrative structures in the cinema of unease." Click here to access this resource online, 2008. http://hdl.handle.net/10292/688.

Full text

Abstract:

This document outlines the research, development and production of a creative work and accompanying exegesis in partial fulfilment of the requirements for the Master of Communication Studies (MCS) programme. It includes the first draft of a feature film screenplay and an exegesis that explores the research conducted, the theoretical context of the work, and analyses the screenwriting process undertaken. The Bobby Calf (2008) is the first draft of a feature film screenplay that uses a non-classical and non-linear narrative structure to tell the story of its main characters and advance the plot. A psychological drama set in rural New Zealand, The Bobby Calf (2008) was originally inspired by the Janet Frame short story The Reservoir (1963), a story based on a group of youngsters who venture forth to discover the forbidden reservoir; a place their parents had forbid them from going. Set in the outskirts of a small farming settlement, the story is a dark and gothic depiction of rural life and the harshness of reality faced by those brought up in a lifestyle they did not choose. The story focuses on the journey of ADAM (21); both as a young boy in 1988 (called JOHNNY) and as a young adult in 1997, and his mother CATH; a woman whose dreams and aspirations for her son and indeed her own life are slowly slipping away. The story centres on Adam as he grows more uncomfortable with how his life has ended up, and his discovery that the life he has been destined to fulfil is not the one he has chosen. Accompanying the screenplay is an exegesis that explores the research conducted previously on the history of non-classical/non-linear narrative structures and the rationale behind the success and limitations of this now-popular form of storytelling. These types of narrative structures are not a new phenomenon, and as many authors have attested, the basis of this form of storytelling is rooted in the history of screenwriting and film making, and borrows many techniques from theatre and literature.

APA, Harvard, Vancouver, ISO, and other styles

48

Sanders, Jennifer Elizabeth. "Investigating Whether Teacher Provided Structure and Autonomy Support Predict Engagement for New Zealand Students with Attention-Deficit/Hyperactivity Disorder." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/581301.

Full text

Abstract:

Students' engagement tends to decline as they progress through school (Anderman, Maehr, & Midgley, 1999; Eccles et al., 1993; Harter, Whitesell, & Kowalski, 1992; National Research Council and the Institute of Medicine, 2004; Yazzie-Mintz, 2010) and disengagement is linked with negative school outcomes such as dropping out of school, retention, failing to earn a diploma, lower grades, and decreased learning (Christenson et al., 2012; DiPerna, Volpe, & Elliot, 2002; Skinner et al., 2009). Youth with ADHD are an at-risk group for lower levels of emotional and behavioral engagement (American Psychiatric Association, 2000). This study investigated whether teacher instructional style (i.e., autonomy support and structure) predicts student engagement and disengagement utilizing an existing dataset collected from 52 students, and their parents and teachers from Dunedin, New Zealand. Student participants met DSM-IV criteria for ADHD, and ranged from 5 to 11 years of age. Class-wide, teacher-provided structure was measured by the Classroom Environment Scale Rule Clarity, and Order and Organization subscales. Class-wide, teacher-provided autonomy support was measured by the Classroom Environment Scale Innovation, Teacher Support, and Teacher Control subscales. Students' emotional engagement in school was measured by Teacher Report Form Working Hard, Happy, Withdrawn, and Anxious/Depressed T-scores. Correlational and multiple regression analysis were used to answer the study's research questions. Results from this study include findings that increased teacher control and lower ADHD severity significantly predicted greater student work effort (engagement). Student age and ADHD severity, and teacher-provided order and organization (structure) were found to significantly predict increased happiness (engagement). Higher teacher-provided structure in the form of rule clarity, order, and organization were found to significantly predict decreased student withdrawn and depressed behaviors (disengagement). In addition, lower teacher-provided order and organization (structure) and higher ADHD severity together were found to significantly predict increased anxious and depressed student behavior (disengagement). If replicated, findings from the current study could inform future intervention research by indicating the components of teachers' instructional styles that may be most influential in engaging students with ADHD in school.

APA, Harvard, Vancouver, ISO, and other styles

49

Skilton, Jennifer Erin. "Invertebrate Responses to Large-Scale Change : Impacts of Eutrophication and Cataclysmic Earthquake Events in a Southern New Zealand Estuary." Thesis, University of Canterbury. Biological Sciences, 2013. http://hdl.handle.net/10092/8725.

Full text

Abstract:

Environmental stress and disturbance can affect the structure and functioning of marine ecosystems by altering their physical, chemical and biological features. In estuaries, benthic invertebrate communities play important roles in structuring sediments, influencing primary production and biogeochemical flux, and occupying key food web positions. Stress and disturbance can reduce species diversity, richness and abundance, with ecological theory predicting that biodiversity will be at its lowest soon after a disturbance with assemblages dominated by opportunistic species. The Avon-Heathcote Estuary in Christchurch New Zealand has provided a novel opportunity to examine the effects of stress, in the form of eutrophication, and disturbance, in the form of cataclysmic earthquake events, on the structure and functioning of an estuarine ecosystem. For more than 50 years, large quantities (up to 500,000m3/day) of treated wastewater were released into this estuary but in March 2010 this was diverted to an ocean outfall, thereby reducing the nutrient loading by around 90% to the estuary. This study was therefore initially focussed on the reversal of eutrophication and consequent effects on food web structure in the estuary as it responded to lower nutrients. In 2011, however, Christchurch was struck with a series of large earthquakes that greatly changed the estuary. Massive amounts of liquefied sediments, covering up to 65% of the estuary floor, were forced up from deep below the estuary, the estuary was tilted by up to a 50cm rise on one side and a corresponding drop on the other, and large quantities of raw sewage from broken wastewater infrastructure entered the estuary for up to nine months. This study was therefore a test of the potentially synergistic effects of nutrient reduction and earthquake disturbance on invertebrate communities, associated habitats and food web dynamics. Because there was considerable site-to-site heterogeneity in the estuary, the sites in this study were selected to represent a eutrophication gradient from relatively “clean” (where the influence of tidal flows was high) to highly impacted (near the historical discharge site). The study was structured around these sites, with components before the wastewater diversion, after the diversion but before the earthquakes, and after the earthquakes. The eutrophication gradient was reflected in the composition and isotopic chemistry of primary producer and invertebrate communities and the characteristics of sediments across the sample sites. Sites closest to the former wastewater discharge pipe were the most eutrophic and had cohesive organic -rich, fine sediments and relatively depauperate communities dominated by the opportunistic taxa Capitellidae. The less-impacted sites had coarser, sandier sediments with fewer pollutants and far less organic matter than at the eutrophic sites, relatively high diversity and lower abundances of micro- and macro-algae. Sewage-derived nitrogen had became incorporated into the estuarine food web at the eutrophic sites, starting at the base of the food chain with benthic microalgae (BMA), which were found to use mostly sediment-derived nitrogen. Stable isotopic analysis showed that δ13C and δ15N values of most food sources and consumers varied spatially, temporally and in relation to the diversion of wastewater, whereas the earthquakes did not appear to affect the overall estuarine food web structure. This was seen particularly at the most eutrophic site, where isotopic signatures became more similar to the cleaner sites over two-and-a-half years after the diversion. New sediments (liquefaction) produced by the earthquakes were found to be coarser, have lower concentrations of heavy metals and less organic matter than old (existing) sediments. They also had fewer macroinvertebrate inhabitants initially after the earthquakes but most areas recovered to pre-earthquake abundance and diversity within two years. Field experiments showed that there were higher amounts of primary production and lower amounts of nutrient efflux from new sediments at the eutrophic sites after the earthquakes. Primary production was highest in new sediments due to the increased photosynthetic efficiency of BMA resulting from the increased permeability of new sediments allowing increased light penetration, enhanced vertical migration of BMA and the enhanced transport of oxygen and nutrients. The reduced efflux of NH4-N in new sediments indicated that the capping of a large portion of eutrophic old sediments with new sediments had reduced the release of legacy nutrients (originating from the historical discharge) from the sediments to the overlying water. Laboratory experiments using an array of species and old and new sediments showed that invertebrates altered levels of primary production and nutrient flux but effects varied among species. The mud snail Amphibola crenata and mud crab Austrohelice crassa were found to reduce primary production and BMA biomass through the consumption of BMA (both species) and its burial from bioturbation and the construction of burrows (Austrohelice). In contrast, the cockle Austrovenus stutchburyi did not significantly affect primary production and BMA biomass. These results show that changes in the structure of invertebrate communities resulting from disturbances can also have consequences for the functioning of the system. The major conclusions of this study were that the wastewater diversion had a major effect on food web dynamics and that the large quantities of clean and unpolluted new sediments introduced to the estuary during the earthquakes altered the recovery trajectory of the estuary, accelerating it at least throughout the duration of this study. This was largely through the ‘capping’ effect of the new liquefied, coarser-grained sediments as they dissipated across the estuary and covered much of the old organic-rich eutrophic sediments. For all aspects of this study, the largest changes occurred at the most eutrophic sites; however, the surrounding habitats were important as they provided the context for recovery of the estuary, particularly because of the very strong influence of sediments, their biogeochemistry, microalgal and macroalgal dynamics. There have been few studies documenting system level responses to eutrophication amelioration and to the best on my knowledge there are no other published studies examining the impacts of large earthquakes on benthic communities in an estuarine ecosystem. This research gives valuable insight and advancements in the scientific understanding of the effects that eutrophication recovery and large-scale disturbances can have on the ecology of a soft-sediment ecosystem.

APA, Harvard, Vancouver, ISO, and other styles

50

Pedley, Katherine Louise. "Modelling Submarine Landscape Evolution in Response to Subduction Processes, Northern Hikurangi Margin, New Zealand." Thesis, University of Canterbury. Geological Sciences, 2010. http://hdl.handle.net/10092/4648.

Full text

Abstract:

The steep forearc slope along the northern sector of the obliquely convergent Hikurangi subduction zone is characteristic of non-accretionary and tectonically eroding continental margins, with reduced sediment supply in the trench relative to further south, and the presence of seamount relief on the Hikurangi Plateau. These seamounts influence the subduction process and the structurally-driven geomorphic development of the over-riding margin of the Australian Plate frontal wedge. The Poverty Indentation represents an unusual, especially challenging and therefore exciting location to investigate the tectonic and eustatic effects on this sedimentary system because of: (i) the geometry and obliquity of the subducting seamounts; (ii) the influence of multiple repeated seamount impacts; (iii) the effects of structurally-driven over-steeping and associated widespread occurrence of gravitational collapse and mass movements; and (iv) the development of a large canyon system down the axis of the indentation. High quality bathymetric and backscatter images of the Poverty Indentation submarine re-entrant across the northern part of the Hikurangi margin were obtained by scientists from the National Institute of Water and Atmospheric Research (NIWA) (Lewis, 2001) using a SIMRAD EM300 multibeam swath-mapping system, hull-mounted on NIWA’s research vessel Tangaroa. The entire accretionary slope of the re-entrant was mapped, at depths ranging from 100 to 3500 metres. The level of seafloor morphologic resolution is comparable with some of the most detailed Digital Elevation Maps (DEM) onshore. The detailed digital swath images are complemented by the availability of excellent high-quality processed multi-channel seismic reflection data, single channel high-resolution 3.5 kHz seismic reflection data, as well as core samples. Combined, these data support this study of the complex interactions of tectonic deformation with slope sedimentary processes and slope submarine geomorphic evolution at a convergent margin. The origin of the Poverty Indentation, on the inboard trench-slope at the transition from the northern to central sectors of the Hikurangi margin, is attributed to multiple seamount impacts over the last c. 2 Myr period. This has been accompanied by canyon incision, thrust fault propagation into the trench fill, and numerous large-scale gravitational collapse structures with multiple debris flow and avalanche deposits ranging in down-slope length from a few hundred metres to more than 40 km. The indentation is directly offshore of the Waipaoa River which is currently estimated to have a high sediment yield into the marine system. The indentation is recognised as the “Sink” for sediments derived from the Waipaoa River catchment, one of two target river systems chosen for the US National Science Foundation (NSF)-funded MARGINS “Source-to-Sink” initiative. The Poverty Canyon stretches 70 km from the continental shelf edge directly offshore from the Waipaoa to the trench floor, incising into the axis of the indentation. The sediment delivered to the margin from the Waipaoa catchment and elsewhere during sea-level high-stands, including the Holocene, has remained largely trapped in a large depocentre on the Poverty shelf, while during low-stand cycles, sediment bypassed the shelf to develop a prograding clinoform sequence out onto the upper slope. The formation of the indentation and the development of the upper branches of the Poverty Canyon system have led to the progressive removal of a substantial part of this prograding wedge by mass movements and gully incision. Sediment has also accumulated in the head of the Poverty Canyon and episodic mass flows contribute significantly to continued modification of the indentation by driving canyon incision and triggering instability in the adjacent slopes. Prograding clinoforms lying seaward of active faults beneath the shelf, and overlying a buried inactive thrust system beneath the upper slope, reveal a history of deformation accompanied by the creation of accommodation space. There is some more recent activity on shelf faults (i.e. Lachlan Fault) and at the transition into the lower margin, but reduced (~2 %) or no evidence of recent deformation for the majority of the upper to mid-slope. This is in contrast to current activity (approximately 24 to 47% shortening) across the lower slope and frontal wedge regions of the indentation. The middle to lower Poverty Canyon represents a structural transition zone within the indentation coincident with the indentation axis. The lower to mid-slope south of the canyon conforms more closely to a classic accretionary slope deformation style with a series of east-facing thrust-propagated asymmetric anticlines separated by early-stage slope basins. North of the canyon system, sediment starvation and seamount impact has resulted in frontal tectonic erosion associated with the development of an over-steepened lower to mid-slope margin, fault reactivation and structural inversion and over-printing. Evidence points to at least three main seamount subduction events within the Poverty Indentation, each with different margin responses: i) older substantial seamount impact that drove the first-order perturbation in the margin, since approximately ~1-2 Ma ii) subducted seamount(s) now beneath Pantin and Paritu Ridge complexes, initially impacting on the margin approximately ~0.5 Ma, and iii) incipient seamount subduction of the Puke Seamount at the current deformation front. The overall geometry and geomorphology of the wider indentation appears to conform to the geometry accompanying the structure observed in sandbox models after the seamount has passed completely through the deformation front. The main morphological features correlating with sandbox models include: i) the axial re-entrant down which the Poverty Canyon now incises; ii) the re-establishment of an accretionary wedge to the south of the indentation axis, accompanied by out-stepping, deformation front propagation into the trench fill sequence, particularly towards the mouth of the canyon; iii) the linear north margin of the indentation with respect to the more arcuate shape of the southern accretionary wedge; and, iv) the set of faults cutting obliquely across the deformation front near the mouth of the canyon. Many of the observed structural and geomorphic features of the Poverty Indentation also correlate well both with other sediment-rich convergent margins where seamount subduction is prevalent particularly the Nankai and Sumatra margins, and the sediment-starved Costa Rican margin. While submarine canyon systems are certainly present on other convergent margins undergoing seamount subduction there appears to be no other documented shelf to trench extending canyon system developing in the axis of such a re-entrant, as is dominating the Poverty Indentation. Ongoing modification of the Indentation appears to be driven by: i) continued smaller seamount impacts at the deformation front, and currently subducting beneath the mid-lower slope, ii) low and high sea-level stands accompanied by variations on sediment flux from the continental shelf, iii) over-steepening of the deformation front and mass movement, particularly from the shelf edge and upper slope.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Structural New Zealand'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles