Literatura académica sobre el tema "Landforms South Australia"
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Artículos de revistas sobre el tema "Landforms South Australia"
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Liu, Zhengyao, Zhibao Dong y Xujia Cui. "Morphometry of lunette dunes in the Tirari Desert, South Australia". Open Geosciences 10, n.º 1 (14 de septiembre de 2018): 452–60. http://dx.doi.org/10.1515/geo-2018-0035.
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Abstract Morphometry and formation processes are key research problems in the study of aeolian sandy landforms. Based on morphometric parameters inferred from satellite images and the calculation of the drift potential (DP), we examined general characteristics of lunette dunes in the Tirari Desert, South Australia, along with their morphometry and formation processes to determine how this landform type initially formed and its relationship to surrounding linear dune distribution. Results show that the morphometric parameters of lunette dunes and connective lake systems exhibit moderate correlations. It suggests that the morphology of these dunes is controlled by the lakes. Spatially, the lunette dunes present regular arrangement, and the strike of their alignment are approximately in accordance with the linear dunes. The calculated DP implies that the lunette dunes developed under a low-wind-energy environment, which is a wind regime similar to that required for the formation of the surrounding linear dunes. Even though, the resultant DP demonstrates that the summer wind should be responsible for the growth of the lunette dunes. However, accompanied with the repeated drying of lakes and even its disappearance during the dune development process, it not only contributes to the development of lunette dunes but also promotes their transformation to linear dunes.
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Peacock, David, Gresley A. Wakelin-King y Ben Shepherd. "Cane toads (Rhinella marina) in south-western Queensland: invasion front, spread and how Cooper Creek geomorphology could enable invasion into north-eastern South Australia". Australian Journal of Zoology 62, n.º 5 (2014): 366. http://dx.doi.org/10.1071/zo14025.
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The invasion of northern Australia by the poisonous cane toad is well recognised, as is its devastating impacts on numerous local native species. However, there is little recognition that the toads are spreading into south-western Queensland. Utilising local knowledge, a limited survey was undertaken within the Cooper Creek catchment to locate the invasion front. Dispersal during 2010–11 floods has established cane toads as far south as Jundah. Integrating this information with landform mapping indicates that cane toad invasion can continue south-west down the Cooper Creek. Though arid, Cooper Creek’s geomorphology renders it partially independent of local climate, and permanent and semipermanent waterholes (including RAMSAR-listed wetlands) are found downstream from Windorah and into the Strzelecki Desert. Natural landforms provide potential daytime shelter and breeding sites, and additional suitable habitat created by human activity is also widespread. Even unsuccessful attempts at breeding may be detrimental to regional ecology, especially fish populations, at critical stages of their boom/bust cycle. We conclude that there is no reason why cane toads cannot penetrate further down the Cooper Creek, threatening wetlands in north-eastern South Australia. Published models of cane toad expansion, which conclude that north-eastern South Australia is too dry for cane toad populations to establish, are based on climatic parameters that significantly under-represent true habitat availability.
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Pain, C. F. "Mapping of landforms from landsat imagery: an example from eastern new south wales, australia". Remote Sensing of Environment 17, n.º 1 (febrero de 1985): 55–65. http://dx.doi.org/10.1016/0034-4257(85)90112-9.
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Matchan, Erin L., David Phillips, Fred Jourdan y Korien Oostingh. "Early human occupation of southeastern Australia: New insights from 40Ar/39Ar dating of young volcanoes". Geology 48, n.º 4 (6 de febrero de 2020): 390–94. http://dx.doi.org/10.1130/g47166.1.
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Abstract In Australia, the onset of human occupation (≥65 ka?) and dispersion across the continent are the subjects of intense debate and are critical to understanding global human migration routes. New-generation multi-collector mass spectrometers capable of high-precision 40Ar/39Ar dating of young (<500 ka) samples provide unprecedented opportunities to improve temporal constraints of archaeological events. In southeastern Australia, a novel approach to improving understanding of occupation involves dating key volcanic eruptions in the region, referenced to stone artifacts and Aboriginal oral traditions. The current study focuses on two monogenetic volcanoes in the Newer Volcanic Province of southeastern Australia: Budj Bim (previously Mount Eccles) and Tower Hill. Budj Bim and its surrounding lava landforms are of great cultural significance and feature prominently in the oral traditions of the Gunditjmara people. Tower Hill is of archaeological significance due to the occurrence of a stone tool beneath tephra. 40Ar/39Ar eruption ages of 36.9 ± 3.1 ka (95% confidence interval) and 36.8 ± 3.8 ka (2σ) were determined for the Budj Bim and Tower Hill volcanic complexes, respectively. The Tower Hill eruption age is a minimum age constraint for human presence in Victoria, consistent with published optically stimulated luminescence and 14C age constraints for the earliest known occupation sites in Tasmania, New South Wales, and South Australia. If aspects of oral traditions pertaining to Budj Bim or its surrounding lava landforms reflect volcanic activity, this could be interpreted as evidence for these being some of the oldest oral traditions in existence.
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Chen, Xiang Yang. "Quaternary sedimentation, parna, landforms, and soil landscapes of the Wagga Wagga 1 : 100 000 map sheet, south-eastern Australia". Soil Research 35, n.º 3 (1997): 643. http://dx.doi.org/10.1071/s96071.
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The Wagga Wagga 1 : 100 000 map sheet is on the Western Slopes of southern New South Wales. The regional topography changes from hills in the east and south-east to gently sloping rises and alluvial plains in the west. Aeolian clays (parna) form a consistent clay regolith regardless of the underlying geology in the gently sloping areas. In some alluvial plains and on some lower hill slopes, the surficial sediments contain a significant portion of reworked parna. In hilly areas, parna is poorly preserved except on some remnant ancient land surfaces, such as dissected plateaux and piedmont plains. The soil pattern in the area is well controlled by landform processes and history. On relatively steep hill slopes, locally derived materials from weathering of bedrock are usually the dominant components of the soils, and geology is the dominant factor controlling soil distribution. In contrast, the Murrumbidgee high floodplain is covered by uniform silty clay with deep clayey soils (brown/grey Dermosols). Before the mid-Holocene, the alluvium mainly comprised sands and gravels, which were reworked by wind forming sand sheets and sand mounds (source-bordering dunes) on which deep sandy soils (Rudosols) now occur. The sediments and soils on the alluvial plains of local streams vary according to their distance from the source area and the flooding frequency. Areas considered to be mantled by parna, uniform red clayey soils (haplic red Kandosols/Chromosols) occur. Although the distribution pattern of the soils is controlled by the landform evolution, the relationships between soil morphological properties and topography are not readily quantified. On the alluvial and gently sloping landforms, soil properties usually show little change even though slope gradient and slope length vary. Some soils, e.g. the Rudosols on the sand sheets, rarely show any topographic features which may indicate their presence. In limited areas, e.g. on steeper hills formed on metasedimentary rock, the soil properties vary with changes in topographic parameters (slope gradient and slope length).
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Summerell, G. K., N. K. Tuteja, R. B. Grayson, P. B. Hairsine y F. Leaney. "Contrasting mechanisms of salt delivery to the stream from three different landforms in South Eastern Australia". Journal of Hydrology 330, n.º 3-4 (noviembre de 2006): 681–97. http://dx.doi.org/10.1016/j.jhydrol.2006.05.002.
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Blake, David, Petter Nyman, Helen Nice, Frances M. L. D'Souza, Christopher R. J. Kavazos y Pierre Horwitz. "Assessment of post-wildfire erosion risk and effects on water quality in south-western Australia". International Journal of Wildland Fire 29, n.º 3 (2020): 240. http://dx.doi.org/10.1071/wf18123.
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Investigations of wildfire impact on water resources have escalated globally over the last decade owing to an awareness of climate-related vulnerabilities. Within Australia, research into post-wildfire erosion has focused on water supply catchments in the south-eastern region. Here, we examine post-wildfire erosion risk and its potential for water quality impacts in a catchment in south-western Australia. The catchment of the Harvey River, which drains from forested escarpments onto an agricultural coastal plain and into valuable coastal wetlands, was burnt by wildfire in 2016. The aims of this study were to determine erosion risk across contrasting landforms and variable fire severity, using the Revised Universal Soil Loss Equation (RUSLE), and to determine whether post-fire water quality impacts could be detected at permanent river monitoring stations located on the coastal plain. RUSLE outputs showed erosion hot-spots at intersections of steep terrain and high fire severity and that these areas were confined to forested headwaters and coastal dunes. Monthly water quality data showed conspicuous seasonal patterns, but that sampling frequency was temporally too coarse to pick up predicted event-related effects, particularly given that the pre-existing monitoring sites were distal to the predicted zone of contamination.
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Daly, RL y KC Hodgkinson. "Relationships Between Grass, Shrub and Tree Cover on Four Landforms of Semi-Arid Eastern Australia, and Prospects for Change by Burning." Rangeland Journal 18, n.º 1 (1996): 104. http://dx.doi.org/10.1071/rj9960104.
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The range of grass, shrub and tree levels present in the Louth region of western New South Wales was determined in an area where woody weeds are considered to be rampant, and the prospects for change by burning were evaluated. Relationships between the three vegetation elements in each of four major landforms were determined by regression and reduction in the canopy cover of woody vegetation after one or two fires were simulated. Basal cover of grass was negatively related to canopy cover of woody vegetation, except in the Sandplains and Dunefields landform. The relationship here was curvilinear with maximum grass cover occurring at 10% canopy cover of the woody vegetation. Pastoralism was considered to become less efficient when the canopy cover of woody vegetation exceeded 5%; 44% of sites measured were below this threshold. The remaining sites could be divided into two groups; one which would fall below the threshold if burnt with a prescribed fire (21%) and the other which required two fires or an equivalent second treatment to reduce the cover below the threshold (35%). The survey confirmed the perception of pastoralists, administrators and scientists that shrub cover is unacceptably high for pastoralism throughout much of the region. Additionally the perennial grass cover was very low and this would increase the instability of forage supply to pastoral herbivores. The high spatial variability in the composition of vegetation indicates that graziers need to identify and treat areas where return on investment in rehabilitation will be highest and most certain.
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Sullivan, B. J., G. S. Baxter y A. T. Lisle. "Low-density koala (Phascolarctos cinereus) populations in the mulgalands of south-west Queensland. I. Faecal pellet sampling protocol". Wildlife Research 29, n.º 5 (2002): 455. http://dx.doi.org/10.1071/wr00110.
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Koala (Phascolarctos cinereus) populations in eastern Australia are threatened by land clearing for agricultural and urban development. At the same time, conservation efforts are hindered by a dearth of information about inland populations. Faecal deposits offer a source of information that is readily available and easily collected non-invasively. We detail a faecal pellet sampling protocol that was developed for use in a large rangeland biogeographic region. The method samples trees in belt transects, uses a thorough search at the tree base to quickly identify trees with koala pellets under them, then estimates the abundance of faecal pellets under those trees using 1-m2 quadrats. There was a strong linear relationship between these estimates and a complete enumeration of pellet abundance under the same trees. We evaluated the accuracy of our method in detecting trees where pellets were present by means of a misclassification index that was weighed more heavily for missed trees that had high numbers of pellets under them. This showed acceptable accuracy in all landforms except riverine, where some trees with large numbers of pellets were missed. Here, accuracy in detecting pellet presence was improved by sampling with quadrats, rather than basal searches. Finally, we developed a method to reliably age pellets and demonstrate how this protocol could be used with the faecal-standing-crop method to derive a regional estimate of absolute koala abundance.
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Cole, I. S., D. A. Paterson, W. D. Ganther, A. Neufeld, B. Hinton, G. McAdam, M. McGeachie et al. "Holistic model for atmospheric corrosion: Part 3 - Effect of natural and man made landforms on deposition of marine salts in Australia and south-east Asia". Corrosion Engineering, Science and Technology 38, n.º 4 (diciembre de 2003): 267–74. http://dx.doi.org/10.1179/147842203225008921.
Texto completoTesis sobre el tema "Landforms South Australia"
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Havel, Jaroslav J. "Ecology of the forests of south western Australia in relation to climate and landforms". Murdoch University, 2000. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060815.114944.
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This thesis sets out to test the hypothesis that the vegetational patterns in the forested region of south western Australia are primarily determined by the interaction of climate and landform.
The region is an area of 4.25 million hectares subject to recent agreement between the Commonwealth of '4ustralia and the state of Western Australia regarding long-term
protection and management of forest (Regional Forest Agreement).
The climate of the South Western forest region is warm temperate and summer dry, matching Koeppen's category Cs, usually described as mediterranean.
The dominant geological features of South Western Australia are crystalline and sedimentary plateaus and coastal plains. They are subject to a complex process of
weathering, denudation and re-deposition, which is the key determinant of landforms and soil patterns. Deep but infertile soils are prevalent.
The dominant vegetation formation of the region is open forest, which reduces to woodland in the drier north and east and increases to tall open forest in the moister
south. Floristically the vegetation is very rich, comprising over 3000 vascular plant species. The richness resides in the forest and woodland understorey and in the
shrublands, heathlands and sedgelands of edaphically extreme sites. By comparison, the forest overstorey is very simple, only one or two species being often dominant
over extensive areas.
The validation of the hypothesis that climate and landforms determine the vegetation patterns in South Western Australia is carried out in the following stages:
1) review of past studies of vegetation patterns in relation to the underlying environmental factors, relating them to one another in terms of floristics,
2) conversion of landform and climate maps for the region into vegetation maps by means of toposequences, that is gradients of topography, soils and vegetation within individual landform/climate combinations,
3) production of two sets of vegetation maps, namely six maps of vegetation complexes (1:250,000) and one map of vegetation systems (1:500,000),
4) testing the predictive capability of the resulting maps by comparing the occurrences of individual species of trees, shrubs and herbs predicted by map
legends, with their records in FloraBase, the geographic information system of the Western Australian Herbarium, and
5) using the outcomes of the above studies to assess the validity of the hypothesis.
Because the above hypothesis is so broad, it will be considered under seven headings:
a) nature of the vegetation patterns (continuum or discrete categories),
b) regional effect of climate and local effect of landform,
c) effect of landforms on soil depth, texture and fertility,
d) joint effect of slope, soil depth and texture on water balance,
e) interactive effect of landform and climate on vegetation patterns,
f) response of individual species to climate and landform, and
g) effect of other factors of environment, such as fire, on vegetation patterns.
The subsidiary hypotheses are defined in Chapter 5.
It is concluded that the vegetation of the region forms a lumpy continuum from the wet south west to the dry north east. Within that broad continuum there are localised
continua from waterlogged sites in depressions to drought-prone sites on steep stony slopes. However, the dominant vegetation of the region is open forest on plateau
uplands with deep infertile soils.
Although climate and landforms have a strong effect on vegetation patterns, they do not determine all vegetation patterns directly. Some tree species have ranges of
occurrence that are too broad for that, and others have ranges that are too restricted.
A more probable explanation is that climate and landforms, together with fire, set the stage on which the interplay of species takes place and determines the structure and
composition of the vegetation. An attempt is made to predict the likely effect of climatic changes on vegetation patterns.
The applicability of the methodology developed to the mapping of other regions, especially the adjacent ones, is examined. A review is made of how the products of
the study, in particular the maps, are currently being used, and suggestions are made how they could be used in the future.
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Havel, J. J. "Ecology of the forests of south western Australia in relation to climate and landforms /". Access via Murdoch University Digital Theses Project, 2000. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060815.114944.
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Spry, Melissa J. y n/a. "The Regolith and landscape evolution of a low relief landscape: Cobar, Central New South Wales, Australia". University of Canberra. Resource, Environmental & Heritage Management, 2003. http://erl.canberra.edu.au./public/adt-AUC20050704.162445.
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Construction of a 1:250,000 scale regolith-landform map of the Cobar area of central New
South Wales (NSW) Australia, demonstrates the presence of a wide range of previously undescribed
regolith materials, landforms and landscape features in the region. The map covers the east-west extent
of the Cobar Basin, extends to the west onto the Darling River Floodplain, and east onto rocks of the
Girilambone Group. The mapping area is centred on the Cobar township and covers -14,730 krn2
between 303113 and 446113 E and 6483184 and 6586183 N (AGO 66, MGA Zone 55). 48 regolithlandform
units have been identified, including both transported (alluvial, colluvial, aeolian, lacustrine)
and in situ materials. A range of siliceous, ferruginous and calcareous indurated materials are also
present.
Four major drainage types have been identified based on lithological, sedimentological and
topographic differences in alluvial materials. The 4 drainage types include: 1) modern drainage; 2)
maghemite and quartzose gravels elevated 1-2 m relative to the modern drainage; 3) higher
topographically inverted, and at least partly silicified, gravels; and, 4) sediments of Cretaceous origin.
Multiple phases of drainage stability and instability from the Cretaceous to the present are indicated
within the sediments. Breaching of drainage divides and increased dissection of the modern drainage,
especially to the south of Cobar, indicate possible tectonic movement across a major regolith-landform
boundary in the southern map area. Colluvial materials are more widespread to the north of Cobar
reflecting the increased landscape dissection to the south. Colluvial fans are preserved adjacent to
major rangefronts. Aeolian and lacustrine materials include longitudinal dunefields of the Darling
River floodplain, source bordering dunes, and small lunettes associated with the Barnato Lakes system.
Regolith-landform mapping at Cobar has been used to assess the applicability of previously
developed landscape evolution models of the Cobar Block and surrounding region, and to develop a
new landscape evolution model for the region. The new landscape evolution model of Cobar indicates
minimal deposition of Cretaceous sediments, succeeded by high-energy early Tertiary fluvial regimes
across the Cobar landscape. Weathering and sediment deposition continued into the Miocene, coupled
with deep valley incision on the Cobar Block associated with early Oligocene regression. By the close
of the Miocene, the Cobar Block had eroded to predominantly bedrock terrain and widespread filling of
previously incised valleys occurred. A decrease in erosion and fluvial activity led to the formation of
the modern drainage during the Pliocene-early Quaternary, followed by the formation of alluvial,
aeolian and lacustrine deposits in the later Quaternary. Regionally, Eromanga Basin sediments were not
extensive over the Cobar Block, and low rates of erosion are recorded at Cobar from the Cretaceous to
the present. Former northerly drainage did exist in this area in the Cretaceous, but was limited in
distribution. By at least the Early Tertiary the Cobar area was a structural high and drainage systems of
the region had assumed their current configuration. These findings do not support interpretations of
AFTT data of significant cover and subsequent stripping over the Cobar Block in the Early Tertiary.
Evidence of landscape evolution from the Cretaceous to the present suggests that the Cobar
landscape has been responding to changes in the primary landscape forming factors of lithology,
climate and to a lesser degree, tectonics. Variations in the these three primary landscape forming
factors have contributed to ongoing weathering, relatively continuous deposition, and periods of
relative stability and instability, particularly in response to climatic and baselevel fluctuations, within a
dynamically evolving landscape throughout the entire Tertiary. Former landscape evolution models of
peneplanation and pediplanation, based on correlation of palaeosurfaces including duricrusts, a deep
weathering profile developed during extended planation in the Early Tertiary, and tectonism during the
late Tertiary in the Cobar area, are not supported by evidence preserved in regolith-landform features at
Cobar.
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Bourne, Jennifer A. "Landform development and stream behaviour in the western piedmont zone of the Flinders Ranges of South Australia". Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phb7753.pdf.
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Six folded maps in pocket inside back cover. Includes bibliographies. Pediments and alluvial fans coexist in the piedment of the Flinders Ranges in the arid to semi-arid interior of South Australia, which thus affords the opportunity to study them in identical geological, climatic and topographic contexts.
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Lau, Ian Christopher. "Regolith-landform and mineralogical mapping of the White Dam Prospect, eastern Olary Domain, South Australia, using integrated remote sensing and spectral techniques". Title page, abstract and table of contents only, 2004. http://hdl.handle.net/2440/37972.
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The research contained within this thesis was directed at examining the spectral properties of regolith-dominated terrains using airborne and proximal hyperspectral instruments. The focus of the investigation was to identify the mineralogy of the regolith and determine if surficial materials were indicative of the underlying bedrock in the regolithdominated terrain of the eastern Olary Domain, South Australia. The research area was constrained to a 250 km2 area around the Cu-Au mineralisation of the White Dam Prosect. Integrated remote sensing, using airborne hyperspectral datasets (HyMap), Landsat imagery and gamma-ray spectroscopy data, was performed to map regolith-landforms and extract information on surficial materials. Detailed calibration of the HyMap dataset, using a modified model-based/empirical line calibration technique, was required prior to information extraction. The White Dam area was able to be divided into: alluvial regolith-dominated; in situ regolith-dominated; and bedrock-dominated terrains, based on mineralogical interpretations of the regolith, using the remotely sensed hyperspectral data. Alluvial regions were characterised by large abundances of vegetation and soils with a hematite-rich mineralogy. Highly weathered areas of in situ material were discriminated by the presence of goethite and kaolinite of various crystallinities, whereas the bedrock-dominated regions displayed white mica-/muscovite-rich mineralogy. Areas flanking bedrock exposures commonly consisted of shallow muscovite-rich soils containing regolith carbonate accumulations. Traditional mineral mapping processes were performed on the HyMap data and were able to extract endmembers of regolith and other surficial materials. The Mixture Tuned Matched Filter un-mixing process was successful at classifying regolith materials and minerals. Spectral indices performed on masked data were effective at identifying the key regolith mineralogical features of the HyMap imagery and proved less time consuming than un-mixing processes. Processed HyMap imagery was able to identify weathering halos, highlighted in mineralogical changes, around bedrock exposures. Proximal spectral measurements and XRD analyses of samples collected from the White Dam Prospect were used to create detailed mineralogical dispersion maps of the surface and costean sections. Regolith materials of the logged sections were found to correlate with the spectrally-derived mineral dispersion profiles. The HyLogger drill core scanning instrument was used to examine the mineralogy of the fresh bedrock, which contrasted with the weathering-derived near-surface regolith materials. The overall outcomes of the thesis showed that hyperspectral techniques were useful for charactering the mineralogy of surficial materials and mapping regolith-landforms.Thesis (Ph.D.)--School of Earth & Environmental Sciences, 2004.
Libros sobre el tema "Landforms South Australia"
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Gibbard, P. L. y J. Ehlers. Quaternary Glaciations - Extent and Chronology, Volume 2: Part III: South America, Asia, Africa, Australia, Antarctica (Developments in Quaternary Sciences). Elsevier Science, 2004.
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Douglas, Kirsty. Pictures of Time Beneath. CSIRO Publishing, 2010. http://dx.doi.org/10.1071/9780643100251.
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Pictures of Time Beneath examines three celebrated heritage landscapes: Adelaide’s Hallett Cove, Lake Callabonna in the far north of South Australia, and the World Heritage listed Willandra Lakes Region of New South Wales. It offers philosophical insights into significant issues of heritage management, our relationship with Australian landscapes, and an original perspective on our understanding of place, time, nation and science.
Glaciers in Adelaide, cow-sized wombats, monster kangaroos, desert dunes littered with freshwater mussels, ancient oases and inland seas: a diverse group of deep-time imaginings is the subject of this ground-breaking book. Ideas about a deep past in Australia are central to broader issues of identity, belonging, uniqueness, legitimacy and intellectual community. This journey through Australia’s natural histories examines the way landscapes and landforms are interpreted to realise certain visions of the land, the nation and the past in the context of contemporary notions of geological heritage, cultural property, cultural identity and antiquity.
Capítulos de libros sobre el tema "Landforms South Australia"
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Twidale, C. R. y J. A. Bourne. "South Australia". En Encyclopedia of the World's Coastal Landforms, 1293–304. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-1-4020-8639-7_231.
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Verstappen, Herman Th. "Volcanic Islands". En The Physical Geography of Southeast Asia. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780199248025.003.0020.
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Volcanism is of widespread occurrence in the tectonically active zones of Southeast Asia. It is a dominant feature in many (particularly smaller) islands where other landform types are absent or scarce. The geographic distribution, major landform types, exogenous and endogenous processes, resources, and hazards of southeast Asian volcanic environments are discussed, first in general terms, and thereafter by using the examples of two typical volcanic islands, Bali and Lombok (Indonesia), which also illustrate the interaction between tectonism and volcanism in this part of the world. The distribution pattern of volcanism in Southeast Asia is related to plate tectonics, as discussed in Chapter 1. Three major plates dominate the region: the Eurasian, Indo-Australian, and Pacific, each of which is composed of several sub-plates. They meet at a triple point situated south of the Bird’s Head of Papua. Volcanism develops where, at some distance from the deep sea trenches that mark subduction zones, the subducting material melts and the magma rises to the surface. Volcanic geanticlinal belts, known as volcanic arcs and stretching parallel to the subduction zones, are thus formed. The arcs are often affected by transcurrent or compartmental faulting, and their roofs may collapse in places. The activity of individual volcanoes comes to an end when the magma chambers concerned are emptied or become inactive otherwise. Volcanism becomes extinct in (part of ) a volcanic arc when subduction abates. It may shift in position with changes in the configurations of the related subduction zone and plates. The plates, subduction zones, and the location of the volcanoes in Southeast Asia are shown in Figure 1.1. All volcanoes discussed in this chapter are Quaternary volcanoes in the sense that the oldest and most eroded ones ended their activity in the Lower Quaternary. The volcanism is of the intermediate andesite–basaltic Circum-Pacific suite, but locally more acidic rocks (rhyolites, dacites, etc.) occur. Neogene volcanic materials, intercalated with marine strata, are common, particularly in the flanks of the volcanic arcs of the region. Volcanic rocks, dating from Cretaceous and older geological periods and related to Pre-Tertiary subduction patterns, occur in Peninsular Malaysia, Borneo, and other areas outside the present arcs.