Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6440956 | Lithos | 2013 | 14 Pages |
Abstract
The characteristic spatial and temporal distributions of high-Mg adakitic rocks along the Tan-Lu fault with emplacement ages of 134-128Â Ma suggest a strong structural control for the emplacement of these intrusions, with magma generation possibly associated with the subduction of the Pacific plate in the early Cretaceous. The low-Mg adakitic rocks (127-120Â Ma) in the Su-Lu orogenic belt were formed later than the high-Mg adakitic rocks, whereas in the Dabie orogenic belt, most of the low-Mg adakitic rocks (143-129Â Ma) were generated earlier than the high-Mg adakitic rocks. Based on available data, we suggest that the large scale strike-slip tectonics of the Tan-Lu fault in the Mesozoic initiated cratonic destruction at the south-eastern margin of the North China Craton, significantly affecting the lower continental crust within areas near the fault. This process resulted in crustal fragments sinking into the asthenosphere and reacting with peridotites, which increased the Mg# of the adakitic melts, generating the high-Mg adakitic rocks. The gravitationally unstable lower continental crust below the Tan-Lu fault in the Su-Lu orogenic belt triggered larger volume delamination of the lower continental crust or foundering of the root.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geochemistry and Petrology
Authors
Hai-Ou Gu, Yilin Xiao, M. Santosh, Wang-Ye Li, Xiaoyong Yang, Andreas Pack, Zhenhui Hou,