Middle triassic post-orogenic extension on Hainan Island: Chronology and geochemistry constraints of bimodal intrusive rocks

Autor: LuLu Fu, Zhongyue Shen, Limei Tang, Chuan-Wan Dong, Shufeng Yang, Hanlin Chen, Xiaogan Cheng
Rok vydání: 2013
Předmět:
Zdroj: Science China Earth Sciences. 56:783-793
ISSN: 1869-1897
1674-7313
DOI: 10.1007/s11430-012-4562-5
Popis: This work studies new petrological and geochemical data and zircon U-Pb ages for bimodal intrusive rocks from Xinglong region, Hainan Island. Zircon U-Pb dating yields mean 238U/206Pb ages of 238 ± 2 Ma and 234 ± 2 Ma for diabasic and granitic phases, respectively, representing the Middle Triassic emplacement. The diabase and granite bodies were formed from discrete mafic and acidic magma sources that experienced local mechanical mixing at their mutual contacts. Although SiO2 content of intrusions is bimodal, trace element ratios indicate that both were formed in a post-orogenic extensional setting. Sr-Nd isotopic composition reflects a shared EMII type enriched mantle source component, possibly influenced by subduction-fluid metasomatism.
Databáze: OpenAIRE
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