Late Jurassic – Early Cretaceous continental extension in northeast Asia – Relationships to plate kinematics
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[1] Université Denis Diderot
Université Denis Diderot
París, Francia
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[2] Université de Rennes
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- Localización: Bulletin de la Société Géologique de France, ISSN 0037-9409, Vol. 188, Nº. 1-2 (Earth Sciences conference of the French-Siberian Centre for Research and Training (FSCRT) ), 2017 (Ejemplar dedicado a: Insights into the geology and paleontology of Siberia from French-Siberian collaboration in Earth Sciences), págs. 10-10
- Idioma: inglés
- Títulos paralelos:
- Cinématique des plaques et extension continentale du nord-est asiatique au Jurassique supérieur-Crétacé inférieur
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Resumen
Northeast Asia is the greatest area in the world where continental extension is documented, from Transbaikalia to the Pacific coast. The major extensional events occurred during Late Jurassic - Early Cretaceous times and are marked by rift basins filled with continental sediments and volcanic rocks, metamorphic core complexes, and extensive magmatism. Here, we review the different types of extensional structures in the region using our own examples from eastern Mongolia, including new data from the Gobi area, and those previously documented in the adjacent regions. We further provide a compilation of available ages, including new data from Transbaikalia, to constrain crustal stretching throughout northeastern Asia. Our analysis shows that extension is not correlated to orogenic collapse, but is coeval with two major changes in plate kinematics that occurred at ca. 140 Ma: the closure of the Mongol-Okhotsk Ocean and a major change in the subduction direction of the Izanagi oceanic plate towards northeast Asia, from high-angle to low-angle convergence. These major changes in plate kinematics combined with an abnormally hot pre-extension state of the continental lithosphere might have triggered spreading in northeast Asia.
