Successive shifts of the India-Africa transform plate boundary during the Late Cretaceous-Paleogene interval: Implications for ophiolite emplacement along transforms
•The Late Cretaceous India-Africa Transform plate boundary is identified at Chain Ridge.•The Paleogene India-Africa transform plate boundary is identified at the Chain Fracture Zone and within the Owen Basin.•The Masirah ophiolites emplaced along a transform boundary.•The oceanic lithosphere subduct...
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Veröffentlicht in: | Journal of Asian earth sciences 2020-04, Vol.191, p.104225, Article 104225 |
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Sprache: | eng |
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Zusammenfassung: | •The Late Cretaceous India-Africa Transform plate boundary is identified at Chain Ridge.•The Paleogene India-Africa transform plate boundary is identified at the Chain Fracture Zone and within the Owen Basin.•The Masirah ophiolites emplaced along a transform boundary.•The oceanic lithosphere subducting nowadays beneath Makran derives from the East Somali Basin instead of Neotethys.
The Arabian Sea in the NW Indian Ocean is a place where two major transform boundaries are currently active: the Owen Fracture Zone between India and Arabia and the Owen Transform between India and Somalia. These transform systems result from the fragmentation of the India-Africa Transform boundary, which initiated about 90 Myrs ago, when the India-Seychelles block separated from Madagascar to move towards Eurasia. Therefore, the geological record of the Arabian Sea makes it possible to investigate the sensitivity of a transform system to several major geodynamic changes.
Here we focus on the evolution of the India-Africa transform system during the ~47–90 Ma interval. We identify the Late Cretaceous (~90–65 Ma) transform plate boundary along Chain Ridge, in the North Somali Basin. From 65 to ~42–47 Ma, the India-Africa transform is identified at the Chain Fracture Zone, which crossed both the Owen Basin and the North East Oman margin. Finally, the transform system jumped to its present-day location in the vicinity of the Owen Ridge. These shifts of the India-Africa boundary with time provide a consistent paleogeographic framework for the emplacement of the Masirah Ophiolitic Belt, which constitutes a case of ophiolite emplaced along a transform boundary. The successive locations of the India-Africa boundary further highlight the origin of the Owen Basin lithosphere incoming into the Makran subduction zone. |
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ISSN: | 1367-9120 1878-5786 |
DOI: | 10.1016/j.jseaes.2019.104225 |