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Showing 1 to 20 of 77 for “"Gondwana"”.
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Supercontinents and glaciation: a perspective from western Gondwana.
… the formation of the Palaeozoic supercontinent Gondwana has long eluded the geological community. Early hypotheses postulated that amalgamation occurred in the mid-late Neopro¬terozoic via a collision between East and West Gondwana. This idea developed with the identification of discrete …
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Terrestrialization and evolutionary radiation of basal embryophytes on the Gondwana
… abundant. On the contrary, the early floras from Gondwana are poorly known, even though this continent gathers the two thirds of the emerged lands in the Pridoli-Lochkovian ages. This work attempts to demonstrate the relevance of the study of Gondwanan early floras for understanding the …
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U-Pb geochronology and structural geology across major shear zones of the Southern granulite terrain of India and organic carbon isotope stratigraphy of the Gondwana coal basins of India : their implications for Gondwana studies
… Peninsular India occupied a central position in Gondwana, this work bears on reconstruction models of central Gondwana between circa 600 Ma and 200 :f1,a. The second part of the thesis (Chapter 6) tests the use of organic carbon isotopes as a chemostratigraphic tool to correlate between the lower …
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Análise filogenética dos Mesoeucrocodylia basais da América do Sul e a evolução do Gondwana (Archosauria: Crocodyliformes)
… of the continental blocks derived from Gondwana. Contrary to previous authors propositions, the results indicate an isolated Africa during the Upper Cretaceous, while South America was linked to Antarctica, lndia, and Madagascar.
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The tectonic evolution of the Southern Granulite Terrane of India and its role in the amalgamation of Gondwana.
… of the Ediacaran-Cambrian supercontinent Gondwana. Bound to the west by Madagascar and the East African continental fragments and to the east by Sri Lanka and Antarctica, this terrane offers a breadth of information regarding across terrane correlations and palaeotectonic settings, …
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Recalibrating the breakup history of SW Gondwana: the first U-Pb chronostratigraphy for the Uitenhage Group, South Africa
… that formed during the Mesozoic breakup of Gondwana are located within the southern Cape region of South Africa. These onshore basins contain the Suurberg and Uitenhage Groups, which are predominantly continental, taphrogenic, fossiliferous strata interbedded with volcaniclastics. Their …
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Aeromagnetics of selected continental areas flanking the Indian Ocean : with implications for geological correlation and reassembly of Central Gondwana
Reassembling continental fragments of Gondwana has been a subject of interest to many since almost the beginning of the last century. As a result, the broad relative position of the major continental fragments and their dispersal history is well understood using marine magnetic anomalies, coastline …
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Origin and Tectonic Evolution of Gondwana Sequence Units Accreted to the Banda Arc: A Structural Transect through Central East Timor
… were conducted to investigate the origin of the Gondwana Sequence in the Timor Region, and to better constrain the tectonic evolution of the active Banda Arc. Our field studies and U/Pb zircon age analysis helped assign most units to either Asian or Australian affinity. Detrital zircon from …
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Quantifying South African uplift : using apatite fission track thermochronology and offshore sediment volumes to test the balance between denudation (onshore) and deposition (offshore) since Gondwana break-up
Includes bibliographical references (leaves 201-217).
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The taxonomy, phylogeny and palaeobiogeography of the trilobite families pliomeridae and encrinuridae: reconstructing the Ordovician world using evolving lineages
… was juxtaposed to the eastern margin of Gondwana and close to areas of South America. Towards the end of the early Ordovician, Laurentia and Gondwana diverged, and did not subsequently re-approach each other during the Period although the Argentine Precordillera was situated in a position …
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Zircon U-PB and LU-HF isotopic data from some peri-gondwana variscan terranes (Sardinia-Corsica block and calabropeloritan arc): new insights on the cenozoic geodynamic evolution of the central mediterranean basin
… the peri-Tyrrhenian area evolution of the peri-Gondwana terranes, amalgamated during Variscan and widespread during Cainozoic opening (and closing) of Tethys, both Variscan and Tertiary rocks cropping out in the two Blocks have been investigated, either magmatic or sedimentary. The first part of …
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Evolution of tectonic and stratigraphic geometries in the Southern Outeniqua Basin
… tectonic context during the Mesozoic break-up of Gondwana. Early Jurassic (170-150Ma) rifting between West and East Gondwana is proposed to have created weaknesses in the crust along the Southern African margin in a NNE-SSW orientation leading to the development of small rift basins and the …
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Petrogenesis of the False Bay dyke swarm, Cape Peninsula, South Africa
… of southern Africa associated with rifting of Gondwana and opening of the South Atlantic Ocean. Previous work highlighted the evolution of a single magma type from olivine-tholeiite basalt to ferro-tholeiite andesite. This thesis presents detailed field observations of each dyke in the False …
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Palaeozoic Palaeomagnetism of South-Eastern Australia
The drift history of Gondwana following the break-up of Rodinia (or perhaps Pannotia) to the amalgamation into Pangaea has great implications in many disciplines in Earth sciences, but remains largely unknown. Among the apparent polar wander (APW) paths published for Gondwana in the last few …
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Taphonomy, palaeoecology and taxonomy of an ophiuroid-stylophoran obrution deposit from the Lower Devonian Bokkeveld Group, South Africa
… cold water Malvinokaffric Realm of southwestern Gondwana. The palaeontological and sedimentological investigations of the Voorstehoek Formation suggest that deposition took place in a shallow marine environment within the storm influenced, proximal part of an offshore transition zone. A …
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Palaeoenvironmental change from the Hettangian to Toarcian in Moyeni (Quthing District), southwestern Lesotho
… Jurassic geological evolution of southern Gondwana. The environment is known to have shifted from wet swamps to a semi-arid fluvio-lacustrine and then to an aeolian system, preceding the outpouring of the Karoo continental flood basalts. The study area at Moyeni in SW Lesotho, exposes the …
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Sedimentology of the lower Uitenhage Group in the Middle to Late Mesozoic Oudtshoorn Basin, South Africa
… have been linked to the break-up of southern Gondwana. Filled by the continental lower Uitenhage Group, which for the most part is sparsely fossiliferous, difficult to correlate on a regional scale and void of non-renewable natural resources, the Oudtshoorn Basin is relatively poorly studied. …
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Oroclines of the Iberian Variscan belt: Tectonic and paleogeographic implications
… along the northern limits of north African Gondwana, from the Arabian-Nubian Shield to the Saharan hinterland. Paleomagnetic data and the distribution of Variscan ophiolites support a model of mid-Paleozoic separation of the Variscan autochthon (Armorican continental ribbon) from north …
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Tectonic and sedimentary history of the Mid-Natal Valley (S.W. Indian Ocean)
… crust, attenuated and subsided in response to Gondwana rifting and drifting, underlies the Central Terrace, Tugela Cone and Mozambique Ridge. Southern margins of the Central Terrace and Tugela Cone are cored by a series of subsea floor ridge and pinnacle complexes (Naude, East Tugela and South …
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