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https://doi.org/10.4154/gc.2019.25
Geochemistry and U-Pb ages of the diabases from the Luoji area, western Yunnan, China: implications for the timing of initial rifting of the Ganzi-Litang Ocean
Chan Wang
; College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan, 610059, China; School of Environment and Earth Science, the University of Queensland, Brisbane, QLD, 4072, Australia
Hao Liu
; School of Environment and Earth Science, the University of Queensland, Brisbane, QLD, 4072, Australia; State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, College of Energy, Chengdu University of technology, Chengdu Sichuan, 610059, Ch
Hanbin Feng
; 4. North China Petroleum Administration Co., Ltd. Sulige Exploration and Development Branch, Shijiazhuang, Hebei, 017300, China
Jianghong Deng
; 1. College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan, 610059, China
Xianfan Liu
; College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan, 610059, China
Fufeng Zhao
; College of Earth Sciences, Chengdu University of Technology, Chengdu, Sichuan, 610059, China
Abstract
Detailed geochemical and U-Pb studies of two diabases (Luoji and Cuiyi) from the Luoji area have been undertaken. The diabases are high-K calc-alkaline and belonging to the tholeiitic series, enriched in large ion lithophile elements, Ti, Zr and light rare earth elements, and depleted in high field strength elements. These characteristics are different from the oceanic island basalt but highly consistent with the continental rift basalt, indicating the Luoji and Cuiyi diabases are the products of the intracontinental rift related to the initial opening of the Ganzi-Litang Ocean. The Luoji and Cuiyi diabases originated from an enriched mantle source with a small degree of crustal contamination during their emplacement. Zircon U-Pb ages show that the Luoji and Cuiyi diabases were emplaced at 293.4±5.4Ma. Therefore, we propose that the time of initial rifting of the Ganzi-Litang Ocean occurred during the very Early Permian.
Keywords
Hrčak ID:
232020
URI
Publication date:
17.12.2019.
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