Lithofacies palaeogeography characteristics of|the Late Permian in Northeast China
Qu Xiyu1, Zhang Manli1, Liu Li2, Wang Dehai2, Qiu Longwei1
1 School of Geosciences, China University of Petroleum(East China), Qingdao 266580, Shandong 2 College of Earth Sciences, Jilin University, Changchun 130061, Jilin
Abstract：Based on 6 measured sections and 38 collected sections, the sedimentary environment and palaeogeographic features of the Late Permian in Northeast China were studied by means of rock association characteristics and element geochemical analysis of the samples. The results showed that the Upper Permian samples exhibited the features with high constant elements including Si, Al and low constant elements including P, Mn, Ca; trace elements with high content of V, Rb, Zr, Ba, Be, Mo, and low content of Cd, Ta, U. Rare earth elements performance showed|significant differentiation|and light rare earth elements were relative enrichment, but Eu was negative anomaly. The main sedimentary environment was reducing continental freshwater environment. And there were three provenances, including northern, eastern and western, the former two of which were the main provenances where developed sediments of delta facies, fan delta facies and lacustrine facies. In addition, abnormality in constant, trace and rare earth elements of the samples at the bottom of Linxi Formation and a large number of carbonate gravels at the bottom of Yangjiagou Formation both demonstrate and appearance of transgression in local area of the beginning of|Late Permian. In summary in Northeast China was marked by the alternation of continental and marine facies and the main sedimentary environment was continental lacustrine in the early Late Permian.
