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| Thompson, Joseph Offei; Moulin, Maryline; Aslanian, Daniel; De Clarens, P.; Guillocheau, F.. |
| The amalgamation of Gondwana and its subsequent fragmentation has been a subject of several studies over the past five decades, yet the very important question of the initial geometry of the supercontinent remains enigmatic. Current reconstruction models of the Indian Ocean are characterized by large gaps, overlaps and misfits of major structural and Cratonic bodies in their fit, and positions of tectonic blocks that are inconsistent with field observations, a phenomenon sustained by inadequate data, long standing debates and a lack of consensus on the nature of major structures and basins in the ocean. Past attempts to reconstruct the initial fit of the ocean has led to varied and complex models, with their own logic and different geographical limits,... |
| Tipo: Text |
Palavras-chave: Gondwana; Plate tectonics; Indian Ocean; PanAfrican structures; Amalgamation; Kinematic evolution. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00481/59298/61992.pdf |
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| Moulin, Maryline; Aslanian, Daniel; Evain, Mikael; Leprêtre, Angelique; Schnurle, Philippe; Verrier, Fanny; Thompson, Joseph Offei; De Clarens, P.; Leroy, S.; Dias, N.; The Pamela‐moz35 Team,. |
| The Natal Valley, offshore Mozambique, is a key area for understanding the evolution of East Gondwana. Within the scope of the integrated multidisciplinary PAMELA project, we present new wide‐angle seismic data and interpretations, which considerably alter Geoscience paradigms. These data reveal the presence of a 30 km‐thick crust that we argue to be of continental nature. This falsifies all the most recent paleo‐reconstructions of the Gondwana. This 30 km‐thick continental crust 1000 m below sea level implies a complex history with probable intrusions of mantle‐derived melts in the lower crust, connected to several occurrences of magmatism, which seems to evidence the crucial role of the lower continental crust in passive margin genesis. |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00598/71055/69368.pdf |
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| Evain, Mikael; Schnurle, Philippe; Lepretre, Angelique; Verrier, Fanny; Watremez, Louise; Thompson, Joseph Offei; De Clarens, Philippe; Aslanian, Daniel; Moulin, Maryline. |
| Deep seismic acquisitions and a new kinematic study recently highlighted the presence of continental crust in both the southern Mozambique's Coastal Plain (MCP) and further offshore in the North Natal Valley (NNV). Such findings falsify previous geodynamic scenarios based on the kinematic overlap between Antarctica and Africa plates, thus profoundly impacting our understanding East-Gondwana break-up. Using an updated position of Antarctica with respect to Africa this study reconsider the formation mechanism of East-African margins and most specifically of the Limpopo margin (LM). Coincident wide-angle and multi-channel seismic data acquired within the PAMELA project are processed to image the sedimentary and deep crustal structure along a profile that runs... |
| Tipo: Text |
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| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00678/79004/81397.pdf |
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| Thompson, Joseph Offei. |
| Gondwana, formed during the Pan-African Orogeny between 720 and 550Ma, composed of Archean and Paleoproterozoic Cratonic cores surrounded by accreted progressively younger terrains of Mesoproterozoic and Neoproterozoic age. The event saw the closure of a number of large ocean basins and the collision of several cratonic blocks to form the largest unit of continental crust (Pangea) on earth for more than 200Ma from the Late Neoproterozoic 550 Ma to the Carboniferous at about 320 Ma. Its subsequent fragmentation has been a subject of several studies over the past five decades, yet the very important question of the initial geometry of the super-continent remains enigma. Current reconstruction models of the Indian Ocean are characterized by large gaps,... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00415/52637/53483.pdf |
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