The Limpopo magma‐rich transform margin, South Mozambique – part 2: Implications for the Gondwana breakup

Type Article
Date 2021-12
Language English
Author(s) Roche V.ORCID1, Leroy S.ORCID1, Guillocheau F.2, Revillon SidonieORCID3, 6, Ruffet G.ORCID2, Watremez L.ORCID4, D’acremont E.1, Nonn C.1, Vetel W.5, Despinois F.5
Affiliation(s) 1 : Sorbonne Université CNRS‐INSU Institut des Sciences de la Terre de Paris ISTeP Paris ,France
2 : Univ Rennes CNRS Géosciences Rennes UMR 611835000 Rennes, France
3 : SEDISOR/LGO UMR IUEM 6538 Plouzané, France
4 : Univ. Lille CNRS Univ. Littoral Côte d’Opale IRD LOG – Laboratoire d’Océanologie et de Géosciences UMR 8187 Lille , France
5 : Totalenergies Exploration et Production Pau, France
6 : SEDISOR/LGO UMR IUEM 6538 Plouzané, France
Source Tectonics (0278-7407) (American Geophysical Union (AGU)), 2021-12 , Vol. 40 , N. 12 , P. e2021TC006914 (23p.)
DOI 10.1029/2021TC006914
WOS© Times Cited 5
Keyword(s) Transform margin, magmatism, strike-slip system, pull-apart, Mozambique, Seismic reflection
Abstract

The rifted continental margins of Mozambique provide excellent examples of continental passive margins with a significant structural variability associated with magmatism and inheritance. Despite accumulated knowledge, the tectonic structure and nature of the crust beneath the South Mozambique Coastal Plain (SMCP) are still poorly known. This study interprets high-resolution seismic reflection data paired with data from industry-drilled wells and proposes a structural model of the Limpopo transform margin in a magma-rich context. Results indicate that the Limpopo transform margin is characterized by an ocean-continent transition that links the Beira-High and Natal valley margin segments and represents the western limit of the continental crust, separating continental volcano-sedimentary infilled grabens from the oceanic crust domain. These basins result from the emplacement of the Karoo Supergroup during a Permo-Triassic tectonic event, followed by an Early Jurassic tectonic and magmatic event. This latter led to the establishment of steady-state seafloor spreading at ca.156 Ma along the SMCP. A Late Jurassic to Early Cretaceous event corresponds to formation of the Limpopo transform fault zone. Which accommodated the SSE-ward displacement of Antarctica with respect to Africa. We define a new type of margin: the magma-rich transform margin, characterized by the presence of voluminous magmatic extrusion and intrusion coincident with the formation and evolution of the transform margin. The Limpopo transform fault zone consists of several syn-transfer and -transform faults rather than a single transform fault. The intense magmatic activity was associated primarily with mantle dynamics, which controlled the large-scale differential subsidence along the transform margin.

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How to cite 

Roche V., Leroy S., Guillocheau F., Revillon Sidonie, Ruffet G., Watremez L., D’acremont E., Nonn C., Vetel W., Despinois F. (2021). The Limpopo magma‐rich transform margin, South Mozambique – part 2: Implications for the Gondwana breakup. Tectonics, 40(12), e2021TC006914 (23p.). Publisher's official version : https://doi.org/10.1029/2021TC006914 , Open Access version : https://archimer.ifremer.fr/doc/00735/84740/