Abstract
According to the temporal-spatial distribution of Neoproterozoic igneous rocks and relative rocks in South China, including ophiolites, arc volcanic and intrusive rocks and subsequent bimodal magmatism, we identified the presence of a Neoproterozoic intra-oceanic arc, continent-arc-continent collision and three tectono-magmatic zones between the Yangtze Block and Cathaysia Block. We have also unraveled the amalgamation and tectono-magmatic histories between the Yangtze and Cathaysia blocks: At ∼1000-860. Ma, northwestward ocean-ocean subduction and southeastward ocean-continent subduction resulted in the intra-oceanic arc magmatism and active continental margin magmatism in the Cathaysia Block respectively. At ∼860-825. Ma, the steepening subduction caused development of back-arc basin in the intra-oceanic arc zone and the slab rollback induced the arc and back-arc magmatism in the Cathaysia Block. Meanwhile, a shallow dip northwestward ocean-continent subduction formed active continental margin magmatism in the Yangtze Block. At ∼825-805. Ma, the continent-arc-continent collision and final amalgamation between the Yangtze and Cathaysia blocks yielded the Jiangnan Orogen. At ∼805-750. Ma, the Jiangnan Orogen collapsed, and the Nanhua rift basin formed. Our study also rules out any Grenvillian Orogenic event and mantle plume activity in South China and indicates a marginal position of South China in the Rodinia supercontinent.
Original language | English |
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Pages (from-to) | 56-87 |
Number of pages | 32 |
Journal | Precambrian Research |
Volume | 309 |
Early online date | 6 Mar 2017 |
DOIs | |
Publication status | Published - May 2018 |
Externally published | Yes |
Keywords
- Neoproterozoic igneous rocks
- Arc-trench-basin system
- Amalgamation of South China
- Jiangnan Orogeny
- Zircon U-Pb-Hf isotopes
- Nd isotopes