Correlation between South China and India and development of double rift
systems in the South China-India Duo during late Neoproterozoic time
Abstract
South China, India and their derivative terranes/blocks preserve a
larger amount of similar magmatic and sedimentary records related to the
tectonic transition from Rodinia to Gondwana. They provide crucial
insights into not only the paleogeographic correlation between them but
also the geodynamic mechanism for such a transition. Our new results
together with published big data from these terranes/blocks point out
that South China kept a linkage with India at least from the late Tonian
(ca. 830 Ma) to Early Cambrian and formed the South China-India Duo
located at the western margin of Rodinia. The identical magmatism and
sedimentation reflect that double late Neoproterozoic rift systems in
the South China-India Duo could have developed owing to the rollback of
subducting oceanic slab beneath them, including an intracontinental rift
(the Nanhua-Aravalli-Delhi rift) separating the Yangtze-Marwar from
Cathaysia-Bundelkhand terranes and a contemporaneous intra-arc rift
along the northern and western margins of the Yangtze Terrane, through
the Marwar Terrane of western India, and then into the Seychelles and
Madagascar terranes. Such an intra-arc rift is also the most feasible
explanation for the common development of coeval arc-like and
extension-related magmatic rocks and extensional sedimentary sequences
on the western margin of the South China-India Duo and in Seychelles and
Madagascar, and even other subduction zones.