GEOCHEMICAL CHARACTERISTICS AND GEOLOGICAL IMPLICATION OF THE RHYOLITE IN BAIYINGAOLAO FORMATION FROM SERIBENG, INNER MONGOLIA
YANG Wen-jing1, CHENG Tian-she1,2, WANG Deng-hong3, XIAO Ying4, ZHANG Quan1
1. Tianjin Institute of Geological Survey, Tianjin 300191, China; 2. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China; 3. Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100083, China; 4. Puguang Gas Plant, Zhongyuan Oilfield, Dazhou 636156, Sichuan Province, China
Abstract：The rhyolite in Early Cretaceous Baiyingaolao Formation from Seribeng of Xiwuqi, Inner Mongolia is characterized by high SiO2(78.32% to 86.80%), total alkaline-rich(3.84% to 7.63% of K2O+Na2O), high Al2O3(8.59% to 13.70%), low MgO, CaO, TiO2 and MnO. The geochemical characteristics of REE and trace elements are similar to those of A-type granite. The characteristics of low Ti/Y, Nb/Y and Ti/Zr, high Rb/Nb and Rb/Y and strong depletion in Sr and Eu indicate that the rhyolitic magma was originated from partial melting of basaltic upper crustal materials. Combining with the regional researching results, it is suggested that the rhyolite was formed in an intra-plate anorogenic extensional setting.
2013, Vol. 22 
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