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Journal articles on the topic 'Southern margin'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Tuitt, Adrian, Simon Holford, Richard Hillis, John Underhill, Derek Ritchie, Howard Johnson, Ken Hitchen, Martyn Stoker, and David Tassone. "Continental margin compression: a comparison between compression in the Otway Basin of the southern Australian margin and the Rockall-Faroe area in the northeast Atlantic margin." APPEA Journal 51, no. 1 (2011): 241. http://dx.doi.org/10.1071/aj10017.

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There is growing recognition that many passive margins have undergone compressional deformation subsequent to continental breakup, including the southern Australian margin. This deformation commonly results in formation of domal anticlines with four-way dip closures that are attractive targets for hydrocarbon exploration, and many such structures host major hydrocarbon accumulations in the Otway and Gippsland basins; however, the driving mechanisms behind formation of these structures are not completely understood. We compare the history of post-breakup compression in the Otway Basin of the southern Australian margin, with that of the Rockall-Faroe area of the northeast Atlantic margin, which has been far more extensively studied with the aim of establishing a better understanding of the genesis and prospectivity of such structures. Both margins have experienced protracted Mesozoic rifting histories culminating in final continental separation in the Eocene, followed by distinct phases of compressional deformation and trap formation. Whilst the structural style of the anticlines in both margins is similar (mainly fault-propagation folds formed during tectonic inversion), the number, amplitude, and length of the structures in the northeast Atlantic margin are much higher than the southern Australian margin. We propose that compressional structures at both margins formed due to far-field stresses related to plate boundaries, but the magnitude of these stresses in the northeast Atlantic margin is likely to have been higher, and the strength of the lithosphere lower. In the northeast Atlantic margin, the presence of Early Cenozoic basalt lava flows may have also contributed to an increase in pore-fluid pressure in the underlying sediment making pre-existing faults more prone to reactivation.

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2

Parsiegla, N., J. Stankiewicz, K. Gohl, T. Ryberg, and G. Uenzelmann-Neben. "Southern African continental margin: Dynamic processes of a transform margin." Geochemistry, Geophysics, Geosystems 10, no. 3 (March 2009): n/a. http://dx.doi.org/10.1029/2008gc002196.

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3

Horozal, Senay, Jang-Jun Bahk, Sang Hoon Lee, Deniz Cukur, Roger Urgeles, Gil Young Kim, Seong-Pil Kim, Byong-Jae Ryu, and Jin-Ho Kim. "Mass-wasting processes along the margins of the Ulleung Basin, East Sea: insights from multichannel seismic reflection and multibeam echosounder data." Geological Society, London, Special Publications 477, no. 1 (April 30, 2018): 107–19. http://dx.doi.org/10.1144/sp477.18.

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AbstractSubmarine landslides represent a major, previously little recognized, geological hazard to the coastal communities. This study investigates the size, depth and degree of submarine landslides along the margins of the Ulleung Basin and examines how the shelf morphology and sediment supply affect the style and occurrence of slope failures. The slopes have experienced at least 38 episodes of submarine failures, which have left clear arcuate-shaped scarps that initiate at water depths of 150–1120 m. Individual landslides comprise volumes over the range 0.1–340 km3, cover 20–800 km2 on the seafloor and have runout distances of up to 50 km from the source. The headwall scarps are observed as being in excess of 500 m high. The height of scarps in the southern margin is significantly larger than in the western margin. Moreover, the volume of mass-transport deposits in the southern margin is also much higher compared to those from the western margin. The occurrence of the broad shelf (30–150 km wide) and high sedimentation rates in the southern margin might have led to large-scale slope failures. In contrast, the narrow shelf (<20 km) and low sedimentation rates in the western margin would only have promoted small-scale mass-wasting events.

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4

Peace, Alexander L., and J. Kim Welford. "Conjugate margins — An oversimplification of the complex southern North Atlantic rift and spreading system?" Interpretation 8, no. 2 (May 1, 2020): SH33—SH49. http://dx.doi.org/10.1190/int-2019-0087.1.

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The prevalence of conjugate margin terminology and studies in the scientific literature is testimony to the contribution that this concept and approach has made to the study of passive margins, and more broadly extensional tectonics. However, when applied to the complex rift, transform, and spreading system of the southern North Atlantic (i.e., the passive margins of Newfoundland, Labrador, Ireland, Iberia, and southern Greenland), it becomes obvious that at these passive continental margin settings, additional geologic phenomena complicate this convenient description. These aspects include (1) the preservation of relatively undeformed continental fragments, (2) formation of transform systems and oblique rifts, (3) triple junctions (with rift and spreading axes), (4) multiple failed rift axes, (5) postbreakup processes such as magmatism, (6) localized subduction, and (7) ambiguity in identification of oceanic isochrons. Comparison of two different published reconstructions of the region indicates the ambiguity in conducting conjugate margin studies. This demonstrates the need for a more pragmatic approach to the study of continental passive margin settings where a greater emphasis is placed on the inclusion of these possibly complicating features in palinspastic reconstructions, plate tectonics, and evolutionary models.

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5

Oldřich, Mauer, Houšková Kateřina, and Mikita Tomáš. "The root system of pedunculate oak (Quercus robur L.) at the margins of regenerated stands." Journal of Forest Science 63, No. 1 (January 30, 2017): 22–33. http://dx.doi.org/10.17221/85/2016-jfs.

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The paper aims to contribute to the determination of reasons causing the irregular growth of young pedunculate oaks occurring at the margins of naturally and artificially regenerated plots neighbouring with adult stands on alluvial sites. It presents analyses of aboveground biometric parameters, mortality, root system architecture of young trees, root density in the soil profile, global solar radiation and soil moisture content in dependence on the location of oaks at the northern, southern, eastern or western margins of the regenerated area and on the distance from the stand margin. The highest impact of the neighbouring adult stand is always recorded on the margin of the regenerated plot while its effect is weakening towards the plot centre, and fading away ca. 7 m behind the crown projection of adult trees. Regardless of the oak location (northern, southern, eastern or western margin), the cause is a high root density of marginal trees of the adult stand, which induces the critical lack of water under their crown projections.

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6

Holford, Simon, Nick Schofield, Justin MacDonald, Ian Duddy, and Paul Green. "Seismic analysis of igneous systems in sedimentary basins and their impacts on hydrocarbon prospectivity: examples from the southern Australian margin." APPEA Journal 52, no. 1 (2012): 229. http://dx.doi.org/10.1071/aj11017.

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The increasing availability of 3D seismic data from sedimentary basins at volcanic and non-volcanic continental margins has provided fundamental new insights into both the storage and transport of magma in the continental crust. As global hydrocarbon exploration increasingly focuses on passive margin basins with evidence for past intrusive and extrusive igneous activity, constraining the distribution, timing and pathways of magmatism in these basins is essential to reduce exploration risk. Producing and prospective Australian passive margin basins where igneous systems have been identified include the Bight, Otway, Bass, Gippsland and Sorell basins of the southern margin. This paper reviews both the impacts of volcanic activity on sedimentary basin hydrocarbon prospectivity (e.g. advective heating, reservoir compartmentalisation and diagenesis), and the styles, distribution and timing of late Cretaceous–Recent extrusive and intrusive igneous activity along basins of the southern Australian margin, providing illustrative examples based on 2D and 3D seismic reflection data.

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7

Bardet, Nathalie. "Maastrichtian marine reptiles of the Mediterranean Tethys: a palaeobiogeographical approach." Bulletin de la Société Géologique de France 183, no. 6 (December 1, 2012): 573–96. http://dx.doi.org/10.2113/gssgfbull.183.6.573.

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AbstractA global comparison of coeval Maastrichtian marine reptiles (squamates, plesiosaurs, chelonians and crocodyliformes) of Europe, New Jersey, northwestern Africa and Middle-East has been performed. More than twenty outcrops and fifty species (half of them being mosasaurids) have been recorded. PEA and Cluster Analysis have been performed using part of this database and have revealed that marine reptile faunas (especially the mosasaurid ones) from the Mediterranean Tethys are clearly segregated into two different palaeobiogeographical provinces: 1) The northern Tethys margin province (New Jersey and Europe), located around palaeolatitudes 30-40°N and developping into warm-temperate environments, is dominated by mosasaurid squamates and chelonioid chelonians; it is characterized by the mosasaurid association of Mosasaurus hoffmanni and Prognathodon sectorius. 2) The southern Tethys margin province (Brazil and the Arabo-African domain), located between palaeolatitudes 20°N-20°S and developping into intertropical environments, is dominated by mosasaurid squamates and bothremydid chelonians; it is characterized by the mosasaurid association of Globidens phosphaticus as well as by Halisaurus arambourgi and Platecarpus (?) ptychodon (Arabo-African domain). These faunal differences are interpreted as revealing palaeoecological preferences probably linked to differences in palaeolatitudinal gradients and/or to palaeocurrents.On a palaeoecological point on view and concerning mosasaurids, the mosasaurines (Prognathodon, Mosasaurus, Globidens and Carinodens) prevail on both margins but with different species. The ichthyophageous plioplatecarpines Plioplatecarpus (Northern margin) and Platecarpus (?) ptychodon (Southern margin) characterise respectively each margin. The halisaurine Halisaurus is present on both margins but with different species. Of importance, the tylosaurines remain currently unknown on the southern Tethys margin and are restricted to higher palaeolatitudes. Chelonians (bothremydids and chelonioids) are respective of each margin, which probably indicates lower dispersal capabilities compared to mosasaurids. The relative scarcity of plesiosaurs and crocodyliformes could be linked to different ecological preferences. The noteworthy crocodyliforme diversity increase in the Palaeogene is probably linked to mosasaurid extinction during the biological crisis of the K/Pg boundary.

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8

Nomikou, Paraskevi, Dimitris Evangelidis, Dimitrios Papanikolaou, Danai Lampridou, Dimitris Litsas, Yannis Tsaparas, Ilias Koliopanos, and Maria Petroulia. "Morphotectonic Structures along the Southwestern Margin of Lesvos Island, and Their Interrelation with the Southern Strand of the North Anatolian Fault, Aegean Sea, Greece." GeoHazards 2, no. 4 (December 14, 2021): 415–29. http://dx.doi.org/10.3390/geohazards2040023.

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A hydrographic survey of the southwestern coastal margin of Lesvos Island (Greece) was conducted by the Naftilos vessel of the Hellenic Hydrographic Service. The results have been included in a bathymetric map and morphological slope map of the area. Based on the neotectonic and seismotectonic data of the broader area, a morphotectonic map of Lesvos Island has been compiled. The main feature is the basin sub-parallel to the coast elongated Lesvos Basin, 45 km long, 10–35 km wide, and 700 m deep. The northern margin of the basin is abrupt, with morphological slopes towards the south between 35° and 45° corresponding to a WNW-ESE normal fault, in contrast with the southern margin that shows a gradual slope increase from 1° to 5° towards the north. Thus, the main Lesvos Basin represents a half-graben structure. The geometry of the main basin is interrupted at its eastern segment by an oblique NW-SE narrow channel of 650 m depth and 8 km length. East of the channel, the main basin continues as a shallow Eastern Basin. At the western part of the Lesvos margin, the shallow Western Basin forms an asymmetric tectonic graben. Thus, the Lesvos southern margin is segmented in three basins with different morphotectonic characteristics. At the northwestern margin of Lesvos, three shallow basins of 300–400 m depth are observed with WNW-ESE trending high slope margins, probably controlled by normal faults. Shallow water marine terraces representing the last low stands of the glacial periods are observed at 140 m and 200 m depth at the two edges of the Lesvos margin. A secondary E-W fault disrupts the two terraces at the eastern part of the southern Lesvos margin. The NE-SW strike-slip fault zone of Kalloni-Aghia Paraskevi, activated in 1867, borders the west of the Lesvos Basin from the shallow Western Basin. The Lesvos bathymetric data were combined with those of the eastern Skyros Basin, representing the southern strand of the North Anatolian Fault in the North Aegean Sea, and the resulted tectonic map indicates that the three Lesvos western basins are pull-aparts of the strike-slip fault zone between the Skyros Fault and the Adramytion (Edremit) Fault. The seismic activity since 2017 has shown the co-existence of normal faulting and strike-slip faulting throughout the 90 km long Lesvos southern margin.

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9

Comelles, Josep M. "Writing at the margin of the margin: medical anthropology in Southern Europe." Anthropology & Medicine 9, no. 1 (April 2002): 7–23. http://dx.doi.org/10.1080/13648470220139983.

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10

Petkovic, Peter. "Velocity Database for Australian Southern Margin Basins." ASEG Extended Abstracts 2003, no. 2 (August 2003): 1–5. http://dx.doi.org/10.1071/aseg2003ab132.

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11

Garzanti, Eduardo, Pieter Vermeesch, Marta Padoan, Alberto Resentini, Giovanni Vezzoli, and Sergio Andò. "Provenance of Passive-Margin Sand (Southern Africa)." Journal of Geology 122, no. 1 (January 2014): 17–42. http://dx.doi.org/10.1086/674803.

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12

Thomas, William A. "The Iapetan rifted margin of southern Laurentia." Geosphere 7, no. 1 (February 2011): 97–120. http://dx.doi.org/10.1130/ges00574.1.

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13

Stern, Robert, William R. Dickinson, and Timothy Lawton. "Introduction: Making the Southern Margin of Laurentia." Geosphere 6, no. 6 (December 2010): 737–38. http://dx.doi.org/10.1130/ges00642.1.

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14

Jennie, Totterdell. "New exploration opportunities along Australia's southern margin." APPEA Journal 52, no. 1 (2012): 29. http://dx.doi.org/10.1071/aj11003.

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The 2012 Australian offshore acreage release includes exploration areas in four southern margin basins. Three large Release Areas in the frontier Ceduna Sub-basin lie adjacent to four exploration permits granted in 2011. The petroleum prospectivity of the Ceduna Sub-basin is controlled by the distribution of Upper Cretaceous marine and deltaic facies and a structural framework established by Cenomanian growth faulting. These Release Areas offer a range of plays charged by Cretaceous marine and coaly source rocks and Jurassic lacustrine sediments. In the westernmost part of the gas-producing Otway Basin, a large Release Area offers numerous opportunities to test existing and new play concepts in underexplored areas beyond the continental shelf. Gas and oil shows in the eastern part of the Release Area confirm the presence of at least two working petroleum systems. In the eastern Otway Basin, several Release Areas are offered in shallow water on the eastern flank of the highly prospective Shipwreck Trough and provide untested targets along the eastern basin margin southward into Tasmanian waters. To the south, a large Release Area in the frontier Sorell Basin provides the opportunity to explore a range of untested targets in depocentres that formed along the western Tasmanian transform continental margin. Two Release Areas offer exploration potential in the under-explored eastern deepwater part of the Gippsland Basin. Geological control is provided by several successful wells indicating the presence of both gas and liquids in the northern area, while the southern area represents the remaining frontier of the basin

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15

JONES, K. A. "Palaeozoic continental margin tectonics in southern Armorica." Journal of the Geological Society 148, no. 1 (January 1991): 55–64. http://dx.doi.org/10.1144/gsjgs.148.1.0055.

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16

Martinez, Fernando, Robert J. Stern, Katherine A. Kelley, Yashuhiko Ohara, Jonathan D. Sleeper, Julia M. Ribeiro, and Maryjo Brounce. "Diffuse Extension of the Southern Mariana Margin." Journal of Geophysical Research: Solid Earth 123, no. 1 (January 2018): 892–916. http://dx.doi.org/10.1002/2017jb014684.

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17

ANGELETTI, L., M. TAVIANI, S. CANESE, F. FOGLINI, F. MASTROTOTARO, A. ARGNANI, F. TRINCARDI, et al. "New deep-water cnidarian sites in the southern Adriatic Sea." Mediterranean Marine Science 15, no. 2 (December 3, 2013): 263. http://dx.doi.org/10.12681/mms.558.

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Recent ROV (Remotely Operated Vehicle) exploration and bottom sampling in the southern Adriatic Sea (Apulian and Montenegrin margins) resulted in the discovery of cnidarian-rich deep-sea habitats in the depth range of ca. 400-700 m. In particular, ROV inspection of Montenegrin canyons reveals the existence of megabenthic communities dominated by a variety of cnidarians, including scleractinians (Madrepora oculata, Lophelia pertusa, Dendrophyllia cornigera), antipatharians (Leiopathes glaberrima) and gorgonians (Callogorgia verticillata) as major habitat forming taxa, often in association with sponges and, subordinately, serpulids. All such cnidarians are new records for the southeastern side of the Adriatic Sea. Our investigation indicates that an almost continuous belt of patchy cold water coral sites occurs along the entire southwestern margin (Apulian), basically connecting the Adriatic populations with those inhabiting the Ionian margin (Santa Maria di Leuca coral province).

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18

Zhou, Xin, Zhong-Hai Li, Taras V. Gerya, and Robert J. Stern. "Lateral propagation–induced subduction initiation at passive continental margins controlled by preexisting lithospheric weakness." Science Advances 6, no. 10 (March 2020): eaaz1048. http://dx.doi.org/10.1126/sciadv.aaz1048.

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Understanding the conditions for forming new subduction zones at passive continental margins is important for understanding plate tectonics and the Wilson cycle. Previous models of subduction initiation (SI) at passive margins generally ignore effects due to the lateral transition from oceanic to continental lithosphere. Here, we use three-dimensional numerical models to study the possibility of propagating convergent plate margins from preexisting intraoceanic subduction zones along passive margins [subduction propagation (SP)]. Three possible regimes are achieved: (i) subducting slab tearing along a STEP fault, (ii) lateral propagation–induced SI at passive margin, and (iii) aborted SI with slab break-off. Passive margin SP requires a significant preexisting lithospheric weakness and a strong slab pull from neighboring subduction zones. The Atlantic passive margin to the north of Lesser Antilles could experience SP if it has a notable lithospheric weakness. In contrast, the Scotia subduction zone in the Southern Atlantic will most likely not propagate laterally.

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19

Zhang, Jingkun, Jian Cao, Yan Wang, Jun Li, Guang Hu, Ni Zhou, and Tianming Shi. "Geochemistry and Genesis of Oil and Gas Seeps in the Junggar Basin, NW China: Implications for Hybrid Petroleum Systems." Geofluids 2019 (August 1, 2019): 1–26. http://dx.doi.org/10.1155/2019/9732674.

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The Junggar Basin of NW China is representative in containing oil and gas seeps worldwide as there are a wide variety of oil and gas seeps over a large area. However, the genesis of these seeps remains poorly known, limiting the understanding of their implications for petroluem geology and hydrocarbon exploration. Here, we investigate 26 samples of oil and gas seeps from nine outcrops within five areas along the margins of the Junggar Basin to determine the geochemical characteristics of the hydrocarbons, constrain their genesis, and discuss future exploration strategies. Results indicate one type of gas seeps and five types of oil seeps. The gas seeps are derived from low-maturity Jurassic source rocks and occur in the Wusu and Dushanzi areas in the western segment of the southern basin. Type 1 oil seeps, sourced from lower Permian rocks (P1f), occur on the northwestern margin. Type 2 oil seeps, derived from middle Permian source rocks (P2l/P2p), occur on the eastern segment of the southern margin and eastern margin of the Junggar Basin. Type 3 oil seeps, with Jurassic source rocks, occur in the Qigu area in the middle segment of the southern basin. Type 4 oil seeps, with Cretaceous source rocks, occur in the Anjihai and Huoerguosi areas within the middle segment of the southern basin. Type 5 oil seeps mainly have Paleogene source rocks with a minor contribution from Jurassic rocks and occur in the Wusu and Dushanzi areas in the western segment of the southern basin with the single-type gas seeps. These results indicate the presence of lacustrine hybrid petroleum systems within the Junggar Basin with complex oil and gas sources and migration-accumulation. Six potential areas along the basin margin were proposed for exploration in the future.

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20

IWATSUKI, YUKIO, and PHILLIP C. HEEMSTRA. "A review of the Acanthopagrus bifasciatus species complex (Pisces: Sparidae) from the Indian Ocean, with redescriptions of A. bifasciatus (Forsskål 1775) and A. catenula (Lacepède 1801) YUKIO IWATSUKI (Japan) & PHILLIP C. HEEMSTRA (South Africa)." Zootaxa 3025, no. 1 (September 14, 2011): 38. http://dx.doi.org/10.11646/zootaxa.3025.1.2.

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The Doublebar Seabream, Acanthopagrus bifasciatus (Forsskål 1775) with two conspicuous vertical black bars across the head has long been recognized as a distinctive species from the Red Sea and Western Indian Ocean. Two distinct colour patterns are associated with two allopatric populations except southern Oman and Somalia which appears to be a zone of overlap: a northern population (Red Sea, through Persian Gulf, to Pakistan) with dorsal and caudal fins immaculate yellow; and a southern population (east coast of Africa from the Horn of Africa to South Africa, Madagascar, and Mascarene Islands) having the dorsal fin with a wide black margin and caudal fin rear margin with a narrow black edge (and both black margins disappearing with growth in specimens over 30 cm SL). Both populations resulted in the two valid species: A. bifasciatus for the northern population and A. catenula (Lacepède 1801) for the southern population. Nominal species (junior synonyms) of the two species are discussed.

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21

Katzung, Gerhard. "The Caledonides at the southern margin of the East European Craton." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 222, no. 1-2 (September 26, 2001): 3–53. http://dx.doi.org/10.1127/njgpa/222/2001/3.

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22

MUTHUKATTURAJA, MARIMUTHU, CHELLIAH BALASUBRAMANIAN, and ALAGUMALAI MURUGAN. "Two new species of Clypeocaenis (Ephemeroptera: Caenidae) from Western Ghats, Southern India." Zootaxa 4722, no. 4 (January 15, 2020): 361–70. http://dx.doi.org/10.11646/zootaxa.4722.4.5.

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Two new species of Clypeocaenis (Ephemeroptera: Caenidae) are described from Gayathripuzha River, Kerala, and Tunga River, Karnataka, Southern India. The species are best distinguished from congeners based on leg and gill characteristics, as follows. Clypeocaenis gayathri sp. nov.: (1) fore tibia with two rows of ventral and lateral filtering setae, femur with bifid spines, middle tibia with trifurcated spines apically; (2) tracheated gill covers with spines and bifurcated ridges on margins, gills III–VI with more numerous fringed bifid fimbriae. Clypeocaenis sharadhae sp. nov.: (1) fore tibia with two rows of long filtering setae on lateral margin and one row on ventral margin arranged vertically, fore tarsus with transverse row of long setae, hind tibia with a row of lanceolate setae on lateral margin; (2) gills III–VI approximately triangular shaped, with fringed bifid fimbriae, gill III with 12 bifurcated and 2 trifurcated fimbriae.

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23

Shevenell, Amelia, and Steven Bohaty. "Southern Exposure: New Paleoclimate Insights From Southern Ocean and Antarctic Margin Sediments." Oceanography 25, no. 3 (September 1, 2012): 106–17. http://dx.doi.org/10.5670/oceanog.2012.82.

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24

Becker, Katharina, Dieter Franke, Michael Schnabel, Bernd Schreckenberger, Ingo Heyde, and Charlotte M. Krawczyk. "The crustal structure of the southern Argentine margin." Geophysical Journal International 189, no. 3 (April 18, 2012): 1483–504. http://dx.doi.org/10.1111/j.1365-246x.2012.05445.x.

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25

ROSS, CHARLES A. "Paleozoic evolution of southern margin of Permian basin." Geological Society of America Bulletin 97, no. 5 (1986): 536. http://dx.doi.org/10.1130/0016-7606(1986)97<536:peosmo>2.0.co;2.

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26

Willcox, J. B., and H. M. J. Stagg. "Australia's southern margin: a product of oblique extension." Tectonophysics 173, no. 1-4 (February 1990): 269–81. http://dx.doi.org/10.1016/0040-1951(90)90223-u.

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27

Hemer, M. A., and D. A. Griffin. "The wave energy resource along Australia’s Southern margin." Journal of Renewable and Sustainable Energy 2, no. 4 (July 2010): 043108. http://dx.doi.org/10.1063/1.3464753.

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28

Hill, Jenna C., Paul T. Gayes, Neal W. Driscoll, Elizabeth A. Johnstone, and George R. Sedberry. "Iceberg scours along the southern U.S. Atlantic margin." Geology 36, no. 6 (2008): 447. http://dx.doi.org/10.1130/g24651a.1.

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29

Plourde, Alexandre P., Michael G. Bostock, Pascal Audet, and Amanda M. Thomas. "Low-frequency earthquakes at the southern Cascadia margin." Geophysical Research Letters 42, no. 12 (June 28, 2015): 4849–55. http://dx.doi.org/10.1002/2015gl064363.

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30

COCKS, L. R. M., W. S. MCKERROW, and C. R. VAN STAAL. "The margins of Avalonia." Geological Magazine 134, no. 5 (September 1997): 627–36. http://dx.doi.org/10.1017/s0016756897007425.

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During Cambrian and earliest Ordovician times, Avalonia was an area forming an integral part of the huge Gondwanan continent, probably along the northern margin of Amazonia, until in early Ordovician (late Arenig or Llanvirn) time it split off from Gondwana, leaving a widening Rheic Ocean to its south. Today, its southern margin with Gondwana extends northeast from east of Cape Cod, Massachusetts, through Nova Scotia north of the Meguma terrane, and thence below sea level to the south of Newfoundland. On the eastern side of the present Atlantic, the southern margin may separate southwest Portugal from the rest of the Iberian Peninsula; it can be traced eastwards with more certainty from the south Cornwall nappes to a line separating the Northern Phyllite Belt (on the southern margin of the Rhenohercynian terrane) and the Mid-German Crystalline High. There is no certain evidence of Avalonian crust to the northeast of the Elbe Line. The northern margin of Avalonia extends westwards from south of Denmark to the British Isles, where it merges with the Iapetus Ocean suture between Scotland and England. Traced westwards, it crosses Ireland and reappears in northern Newfoundland to the east of New World Island, where it may follow the trace of the Dog Bay Line and the Cape Ray Fault. Recent work suggests that the northern margin of Avalonia may clip the northern tip of Cape Breton Island in Nova Scotia, and then enter the North American mainland at the Bay of Chaleur; it may then be traced from north and west of the Popelogan and Bronson Hill arcs to Long Island Sound near Newhaven, Connecticut. The Cambrian to Devonian faunas reflect the history of Avalonia: initially they were purely Gondwanan but, as Ordovician time proceeded, more genera crossed firstly the Tornquist Ocean as it narrowed between Avalonia and Baltica to close in latest Ordovician and early Silurian times, and secondly the Iapetus Ocean, so that by the early Silurian most of the benthic shelly faunas, apart from the ostracods, were the same round the adjacent margins of all three palaeocontinents.

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31

Hill, K. A., D. M. Finlayson, K. C. Hill, and G. T. Cooper. "MESOZOIC TECTONICS OF THE OTWAY BASIN REGION: THE LEGACY OF GONDWANA AND THE ACTVE PACIFIC MARGIN—A REVIEW AND ONGOING RESEARCH." APPEA Journal 35, no. 1 (1995): 467. http://dx.doi.org/10.1071/aj94030.

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Mesozoic extension along Australia's southern margin and the evolution and architecture of the Otway Basin were probably controlled by three factors: 1) changes in global plate movements driven by mantle processes; 2) the structural grain of Palaeozoic basement; and, 3) changes in subduction along Gondwana's Pacific margin. Major plate realignments controlled the Jurassic onset of rifting, the mid-Cretaceous break-up and the Eocene onset of rapid spreading in the Southern Ocean.The initial southern margin rift site was influenced by the northern limit of Pacific margin (extensional) Jurassic dolerites and the rifting may have terminated dolerite emplacement. Changed conditions of Pacific margin subduction (e.g. ridge subduction) in the Aptian may have placed the Australia-Antarctic plates into minor compression, abating Neocomian southern margin rifting. It also produced vast amounts of volcanolithic sediment from the Pacific margin arc that was funnelled down the rift graben, causing additional regional subsidence due to loading. Albian orogenic collapse of the Pacific margin, related to collision with the Phoenix Plate, influenced mid-Cretaceous breakup propagating south of Tasmania and into the Tasman Sea.Major offsets of the spreading axis during breakup, at the Tasman and Spencer Fracture zones, were most likely controlled by the location of Palaeozoic terrane boundaries. The Tasman Fracture System was reactivated during break-up, with considerable uplift and denudation of the Bass failed rift to the east, which controlled Otway Basin facies distribution. Palaeozoic structures also had a significant effect in determining the half graben orientations within a general N-S extensional regime during early Cretaceous rifting. The late Cretaceous second stage of rifting, seaward of the Tartwaup, Timboon and Sorell fault zones, left a stable failed rift margin to the north, but the attenuated lithosphere of the Otway-Sorell microplate to the south records repeated extension that led to continental separation and may be part of an Antarctic upper plate.

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Teasdale, J. P., L. L. Pryer, P. G. Stuart-Smith, K. K. Romine, M. A. Etheridge, T. S. Loutit, and D. M. Kyan. "STRUCTURAL FRAMEWORK AND BASIN EVOLUTION OF AUSTRALIA’S SOUTHERN MARGIN." APPEA Journal 43, no. 1 (2003): 13. http://dx.doi.org/10.1071/aj02001.

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The structural evolution of all of the Southern Margin Basins can be explained by episodic reactivation of basement structures in respect to a specific sequence of tectonic events. Three geological provinces dominate the basement geology of the Southern Margin basins. The Eyre, Ceduna, Duntroon and Polda Basins overlie basement of the Archean to Proterozoic Gawler-Antarctic Craton. The Otway and Sorell Basins overlie basement of the Neoproterozoic-early Palaeozoic Adelaide- Kanmantoo Fold Belt. The Bass and Gippsland Basins overlie basement of the Palaeozoic Lachlan Fold Belt. The contrasting basement terranes within the three basement provinces and the structures within and between them significantly influenced the evolution and architecture of the Southern Margin basins.The present-day geometry was established during three Mesozoic extensional basin phases:Late Jurassic–Early Cretaceous NW–SE transtension forming deep rift basins to the west and linked pullapart basins and oblique graben east of the Southwest Ceduna Accommodation Zone; Early–Mid Cretaceous NE–SW extension; and Late Cretaceous NNE–SSW extension leading to continental breakup. At least three, potentially trap forming, inversion events have variably influenced the Southern Margin basins; Mid Cretaceous, Eocene, and Miocene-Recent. Volcanism occurred along the margin during the Late Cretaceous and sporadically through the Tertiary.First-order structural control on Mesozoic rifting and breakup were east–west trending basement structures of the southern Australian fracture zone. Second-order controls include:Proterozoic basement shear zones and/or terrane boundaries in the western Gawler Craton, which controlled basin evolution in the Eyre and Ceduna Subbasins; Neoproterozoic structures, which significantly influenced basin evolution in the Ceduna sub-basin; Cambro-Ordovician basement shear zones and/or terrane boundaries, which were a primary control on basin evolution in the Otway and Sorell Basins; and Palaeozoic structures in the Lachlan Fold Belt, which controlled basin evolution in the Bass and Gippsland Basins.A SEEBASE™ (Structurally Enhanced view of Economic Basement) model for the Southern Margin basins has been constructed to show basement topography. When used in combination with a rigorous interpretation of the structural evolution of the margin, it provides a foundation for basin phase and source rock distribution, hydrocarbon fluid focal points and trap type/distribution.

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Spooner, Cameron, Randell Stephenson, and Robert W. H. Butler. "Pooled subsidence records from numerous wells reveal variations in pre-break-up rifting along the proximal domains of the Iberia–Newfoundland continental margins." Geological Magazine 156, no. 08 (November 22, 2018): 1323–33. http://dx.doi.org/10.1017/s0016756818000651.

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AbstractThe Iberia–Newfoundland continental margin is one of the most-studied conjugate margins in the world. However, many unknowns remain regarding the nature of rifting preceding its break-up. We analyse a large dataset of tectonic subsidence curves, created from publicly available well data, to show spatial and temporal trends of rifting in the proximal domains of the margin. We develop a novel methodology of bulk averaging tectonic subsidence curves that can be applied on any conjugate margin with a similar spread of well data. The method does not rely on the existence of conjugate, deep seismic profiles and, specifically, attempts to forego the risk of quantitative bias derived from localized anomalies and uncertain stratigraphic dating and correlation. Results for the Iberia–Newfoundland margin show that active rift-driven tectonic subsidence occurred in the Central segment of the conjugate margin from c. 227 Ma (early Norian) to c. 152.1 Ma (early Tithonian), in the southern segment from c. 208.5 Ma (early Rhaetian) to c. 152.1 Ma (early Tithonian) and in the northern segment from c. 201.3 Ma (early Hettangian) to c. 132.9 Ma (early Hauterivian). This indicates that rifting in the stretching phase of the proximal domain of the Iberia–Newfoundland margin does not mirror hyperextended domain rifting trends (south to north) that ultimately led to break-up. The insights into broad-scale three-dimensional spatial and temporal trends, produced using the novel methodology presented in this paper, provide added value for interpretation of the development of passive margins, and new constraints for modelling of the formation of conjugate margins.

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Bromwich, David H., E. Richard Toracinta, Robert J. Oglesby, James L. Fastook, and Terence J. Hughes. "LGM Summer Climate on the Southern Margin of the Laurentide Ice Sheet: Wet or Dry?*." Journal of Climate 18, no. 16 (August 15, 2005): 3317–38. http://dx.doi.org/10.1175/jcli3480.1.

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Abstract Regional climate simulations are conducted using the Polar fifth-generation Pennsylvania State University (PSU)–NCAR Mesoscale Model (MM5) with a 60-km horizontal resolution domain over North America to explore the summer climate of the Last Glacial Maximum (LGM: 21 000 calendar years ago), when much of the continent was covered by the Laurentide Ice Sheet (LIS). Output from a tailored NCAR Community Climate Model version 3 (CCM3) simulation of the LGM climate is used to provide the initial and lateral boundary conditions for Polar MM5. LGM boundary conditions include continental ice sheets, appropriate orbital forcing, reduced CO2 concentration, paleovegetation, modified sea surface temperatures, and lowered sea level. The simulated LGM summer climate is characterized by a pronounced low-level thermal gradient along the southern margin of the LIS resulting from the juxtaposition of the cold ice sheet and adjacent warm ice-free land surface. This sharp thermal gradient anchors the midtropospheric jet stream and facilitates the development of synoptic cyclones that track over the ice sheet, some of which produce copious liquid precipitation along and south of the LIS terminus. Precipitation on the southern margin is orographically enhanced as moist southerly low-level flow (resembling a contemporary Great Plains low-level jet configuration) in advance of the cyclone is drawn up the ice sheet slope. Composites of wet and dry periods on the LIS southern margin illustrate two distinctly different atmospheric flow regimes. Given the episodic nature of the summer rain events, it may be possible to reconcile the model depiction of wet conditions on the LIS southern margin during the LGM summer with the widely accepted interpretation of aridity across the Great Plains based on geological proxy evidence.

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Cawthra, H. C., E. W. Bergh, E. A. Wiles, and J. S. Compton. "Late Quaternary deep marine sediment records off southern Africa." South African Journal of Geology 124, no. 4 (December 1, 2021): 1007–32. http://dx.doi.org/10.25131/sajg.124.0059.

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Abstract High-resolution mapping, sampling and analysis of upper Quaternary southern African continental margin sediments recovered from beyond the Last Glacial Maximum shoreline (>130 m water depth) have expanded our understanding of how marine and terrestrial records are linked over glacial-interglacial climatic cycles. This paper synthesises data currently available from the deep seafloor around southern Africa and, specifically, core sites that demonstrate terrestrial sedimentological connectivity. Several proxies and case studies reveal the evolution of depositional systems, palaeoceanography and palaeoclimate over the last 191 kyr. Hydroacoustic mapping and investigations of submarine canyons have been carried out primarily on the eastern and southwestern margins, while palaeoceanographic productivity and microfossil assemblages have been applied most extensively on the western marine and southern Agulhas Bank. Studies on the western margin indicate that enhanced productivity, less oxygenated bottom waters and reduced marine faunal diversity in the transition to glacial periods, while glacial terminations are associated with reduced productivity and more oxygenated bottom waters. These changes, linked to palaeoceanography and late Quaternary sea-level fluctuations, influence the sedimentary record and sedimentation rates. On the eastern margin, sediment fluxes applied as proxies for rainfall offshore of the Great Kei, Umzimvubu, Limpopo and Zambezi rivers indicate that the southern African climate responds to changes in orbitally-modulated insolation and in particular, to the ~23 kyr precessional cycle, where the proxy records keep pace with this and then diverge at ~80 to 70 kyr. Since the penultimate glacial (Marine Isotope Stage/MIS 6), more humid conditions observed in southern Africa, as the Northern Hemisphere entered phases of rapid cooling, were potentially driven by a combination of warming in the Agulhas Current and shifts of the subtropical anticyclones. Broadly, the sedimentary records reviewed suggest fluctuations in climate and oceanographic circulation that are strongly correlated with the global benthic δ18O record, suggesting sensitivity to high-latitude forcing, and a strong influence of late Quaternary glacial-interglacial cycles despite these marine sites being far-removed from terrestrial environments.

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36

Gallagher, Kerry, and Roderick Brown. "Denudation and uplift at passive margins: the record on the Atlantic Margin of southern Africa." Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences 357, no. 1753 (April 15, 1999): 835–59. http://dx.doi.org/10.1098/rsta.1999.0354.

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37

Finlayson, D. M., I. Lukaszyk, C. D. N. Collins, and E. C. Chudyk. "Otway Continental Margin Transect: Crustal architecture from wide‐angle seismic profiling across Australia's southern margin." Australian Journal of Earth Sciences 45, no. 5 (October 1998): 717–32. http://dx.doi.org/10.1080/08120099808728428.

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38

Arsdale, Roy Van, Jodi Purser, William Stephenson, and Jack Odum. "Faulting along the southern margin of Reelfoot Lake, Tennessee." Bulletin of the Seismological Society of America 88, no. 1 (February 1, 1998): 131–39. http://dx.doi.org/10.1785/bssa0880010131.

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Abstract The Reelfoot Lake basin, Tennessee, is structurally complex and of great interest seismologically because it is located at the junction of two seismicity trends of the New Madrid seismic zone. To better understand the structure at this location, a 7.5-km-long seismic reflection profile was acquired on roads along the southern margin of Reelfoot Lake. The seismic line reveals a westerly dipping basin bounded on the west by the Reelfoot reverse fault zone, the Ridgely right-lateral transpressive fault zone on the east, and the Cottonwood Grove right-lateral strike-slip fault in the middle of the basin. The displacement history of the Reelfoot fault zone appears to be the same as the Ridgely fault zone, thus suggesting that movement on these fault zones has been synchronous, perhaps since the Cretaceous. Since the Reelfoot and Ridgely fault systems are believed responsible for two of the main-shocks of 1811-1812, the fault history revealed in the Reelfoot Lake profile suggests that multiple mainshocks may be typical of the New Madrid seismic zone. The Ridgely fault zone consists of two northeast-striking faults that lie at the base of and within the Mississippi Valley bluff line. This fault zone has 15 m of post-Eocene, up-to-the-east displacement and appears to locally control the eastern limit of Mississippi River migration. The Cottonwood Grove fault zone passes through the center of the seismic line and has approximately 5 m of up-to-the-east displacement. Correlation of the Cottonwood Grove fault with a possible fault scarp on the floor of Reelfoot Lake and the New Markham fault north of the lake suggests the Cottonwood Grove fault may change to a northerly strike at Reelfoot Lake, thereby linking the northeast-trending zones of seismicity in the New Madrid seismic zone.

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39

Gallart, Francesc, and Nuria Clotet-Perarnau. "Geomorphic Systems on the Southern Margin of the Pyrenees." Mountain Research and Development 10, no. 3 (August 1990): 215. http://dx.doi.org/10.2307/3673601.

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40

Ridgway, Kenneth D., and Lucy M. Flesch. "Cenozoic tectonic processes along the southern Alaska convergent margin." Geology 35, no. 11 (2007): 1055. http://dx.doi.org/10.1130/focus112007.1.

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41

Goldfinger, C. "Super-scale Failure of the Southern Oregon Cascadia Margin." Pure and Applied Geophysics 157, no. 6-8 (August 1, 2000): 1189–226. http://dx.doi.org/10.1007/s000240050023.

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42

Marinho, Martha, Jean Mascle, and Jacques Wannesson. "Structural framework of the southern Guinean margin (Central Atlantic)." Journal of African Earth Sciences (and the Middle East) 7, no. 2 (January 1988): 401–8. http://dx.doi.org/10.1016/0899-5362(88)90085-1.

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43

Hardy, Clément, Catherine Homberg, Yehuda Eyal, Éric Barrier, and Carla Müller. "Tectonic evolution of the southern Levant margin since Mesozoic." Tectonophysics 494, no. 3-4 (November 2010): 211–25. http://dx.doi.org/10.1016/j.tecto.2010.09.007.

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44

Gopalakrishna, D., E. C. Hansen, A. S. Janardhan, and R. C. Newton. "The Southern High-Grade Margin of the Dharwar Craton." Journal of Geology 94, no. 2 (March 1986): 247–60. http://dx.doi.org/10.1086/629026.

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45

KNELLER, B. C. "A foreland basin on the southern margin of Iapetus." Journal of the Geological Society 148, no. 2 (March 1991): 207–10. http://dx.doi.org/10.1144/gsjgs.148.2.0207.

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46

Pallavicini, Yesica, Fernando Bastida, Eva Hernández-Plaza, Sandrine Petit, Jordi Izquierdo, and Jose L. Gonzalez-Andujar. "Local Factors Rather than the Landscape Context Explain Species Richness and Functional Trait Diversity and Responses of Plant Assemblages of Mediterranean Cereal Field Margins." Plants 9, no. 6 (June 22, 2020): 778. http://dx.doi.org/10.3390/plants9060778.

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Arable field margins are valuable habitats providing a wide range of ecosystem services in rural landscapes. Agricultural intensification in recent decades has been a major cause of decline in plant diversity in these habitats. However, the concomitant effects on plant functional diversity are less documented, particularly in Mediterranean areas. In this paper, we analyzed the effect of margin width and surrounding landscape (cover and diversity of land use and field size), used as proxies for management intensity at local and landscape scales, on plant species richness, functional diversity and functional trait values in margins of winter cereal fields in southern Spain. Five functional traits were selected: life form, growth form, seed mass, seed dispersal mode and pollination type. RLQ and fourth-corner analyses were used to link functional traits and landscape variables. A total of 306 plant species were recorded. Species richness and functional diversity were positively related to margin width but showed no response to landscape variables. Functional trait values were affected neither by the local nor landscape variables. Our results suggest that increasing the margin width of conventionally managed cereal fields would enhance both taxonomic and functional diversity of margin plant assemblages, and thus the services they provide to the agro-ecosystem.

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47

Holford, Simon, Richard Hillis, Ian Duddy, Paul Green, Martyn Stoker, Adrian Tuitt, Guillaume Backé, David Tassone, and Justin MacDonald. "Cenozoic post-breakup compressional deformation and exhumation of the southern Australian margin." APPEA Journal 51, no. 1 (2011): 613. http://dx.doi.org/10.1071/aj10044.

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We present results from a margin-wide analysis of the history of post-breakup Cenozoic compressional deformation and related exhumation along the passive southern margin of Australia, based on a regional synthesis of seismic, stratigraphic and thermochronological data. The Cenozoic sedimentary record of the southern margin contains regional unconformities of intra-Lutetian and late Miocene–Pliocene age, which coincide with reconfigurations of the boundaries of the Indo-Australian Plate. Seismic data show that post-breakup compressional deformation and sedimentary basin inversion—characterised by reactivation of syn-rift faults and folding of post-rift sediments—is pervasive from the Gulf St Vincent to Gippsland basins, and occurred almost continually since the early- to mid-Eocene. Inversion structures are absent from the Bight Basin, which we interpret to be the result of both the unsuitable orientation of faults for reactivation with respect to post-breakup stress fields, and the colder, stronger lithosphere that underlies that part of the margin. Compressional deformation along the southeastern margin has mainly been accommodated by reactivation of syn-rift faults, resulting in folds with varying ages and amplitudes in the post-rift Cenozoic succession. Many hydrocarbon fields in the Otway and Gippsland basins are located in these folds, the largest of which are often associated with substantial localised exhumation. Our results emphasise the importance of constraining the timing of Cenozoic compression and exhumation in defining hydrocarbon prospectivity of the southern margin.

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48

Scambos, Ted A., Keith A. Echelmeyer, Mark A. Fahnestock, and Robert A. Bindschadler. "Development of enhanced ice flow at the southern margin of Ice Stream D, Antarctica." Annals of Glaciology 20 (1994): 313–18. http://dx.doi.org/10.3189/1994aog20-1-313-318.

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A combination of image-based velocity mapping techniques and finite-element modeling has been used to study a part of the southern shear margin of Ice Stream D, Antarctica. The study area is a region over which the margin shows considerable development morphologically, where a new southern margin is forming in response to an abrupt increase in ice-stream width just upstream of the study area. A series of ice-speed profiles perpendicular to the margin was determined by semiautomated displacement measurements of small ice features in sequential Landsat TM images. Transverse speed gradients ∂u/∂y of these profiles were determined by calculating the slope of a high-order polynomial fit to the speed profiles. Maximum ice speed and ∂u/∂y increase dramatically as the margin develops in the downstream direction, from 420 to 670 mal,and from 0.02 to 0.16 a, respectively. Finite-element modeling of the upstream and downstream profiles suggests that a considerable change occurs in the stiffness of the ice in the marginal zone between the two profiles, and in the stiHness or amount of sliding in the basal layer underlying the margin. Ice in the downstream profile appears to have marginal zones of softer ice in which shear strain is concentrated and uniformly low resistance to deformation in the bed. For the upstream profile, modeling suggests that the ice is not softened near the margin and that the bed is stiffer near the margin. Model-based calculations suggest that the bed shear is responsible for 69% of the resistance to flow in the upstream margin area;this value is 51 % in the downstream area.

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49

Scambos, Ted A., Keith A. Echelmeyer, Mark A. Fahnestock, and Robert A. Bindschadler. "Development of enhanced ice flow at the southern margin of Ice Stream D, Antarctica." Annals of Glaciology 20 (1994): 313–18. http://dx.doi.org/10.1017/s0260305500016621.

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A combination of image-based velocity mapping techniques and finite-element modeling has been used to study a part of the southern shear margin of Ice Stream D, Antarctica. The study area is a region over which the margin shows considerable development morphologically, where a new southern margin is forming in response to an abrupt increase in ice-stream width just upstream of the study area. A series of ice-speed profiles perpendicular to the margin was determined by semiautomated displacement measurements of small ice features in sequential Landsat TM images. Transverse speed gradients ∂u/∂y of these profiles were determined by calculating the slope of a high-order polynomial fit to the speed profiles. Maximum ice speed and ∂u/∂y increase dramatically as the margin develops in the downstream direction, from 420 to 670 mal,and from 0.02 to 0.16 a, respectively. Finite-element modeling of the upstream and downstream profiles suggests that a considerable change occurs in the stiffness of the ice in the marginal zone between the two profiles, and in the stiHness or amount of sliding in the basal layer underlying the margin. Ice in the downstream profile appears to have marginal zones of softer ice in which shear strain is concentrated and uniformly low resistance to deformation in the bed. For the upstream profile, modeling suggests that the ice is not softened near the margin and that the bed is stiffer near the margin. Model-based calculations suggest that the bed shear is responsible for 69% of the resistance to flow in the upstream margin area;this value is 51 % in the downstream area.

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50

Wang, Yanpeng, Wentao Yang, Shenyuan Peng, Shuaishuai Qi, and Deshun Zheng. "Early Triassic Conversion from Source to Sink on the Southern Margin of the North China Craton: Constraints by Detrital Zircon U-Pb Ages." Minerals 10, no. 1 (December 19, 2019): 7. http://dx.doi.org/10.3390/min10010007.

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Provenance analysis of sediments provides important constraints on basin formation and orogenic processes. With the aim to define the sedimentary provenance and tectonic evolution of the southern margin of the North China Craton, this paper presents new detrital zircon U-Pb data from Early Triassic sediments in the Yiyang area. The results showed major peaks at 1848, 458, 425, and 268 Ma and subordinate peaks at ca. 2500, 872, and 957 Ma on age spectra from the Liujiagou Formation. The Heshanggou Formation exhibited a major age peak at 445 Ma and subordinate peaks at 755 and 947 Ma. Integrated with the analysis of sandstone detrital compositions, we suggest that the sources of the Liujiagou Formation were mainly a mixture of the southern margin of the North China Craton and the North Qinling Orogenic Belt, whereas the Heshanggou Formation was derived primarily from the North Qinling Orogenic Belt. Age comparisons of detrital zircon geochronology collected from different basins in the North China Craton indicated that the paleogeography of the North China Craton during the Early Triassic was strongly asymmetric, wherein the uplifted highland along the southern margin of the North China Craton was relatively lower than the northern margin. Meanwhile, the marked shift in source region from the Liujiagou to the Heshanggou formations provides a constraint regarding the conversion from denuded zone to deposited zone along the southern margin of the North China Craton in the Early Triassic, which controlled the evolution of the provenance and sedimentary system.

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