Reconsideration of the sediment characteristics of the second member of the Triassic Xujiahe Formation in Sanhuiba,Huaying Mountain

作     者：LIAO Taiping HU Jingjing ZHANG Furong LIU Lijing 

作者机构：Chongqing University of Science and Technology Chongqing 401331 China Research Institute of Petroleum Exploration and Development PetroChina Beijing 100083 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China 

出 版 物：《Mining Science and Technology》 (矿业科学技术（英文版）)

年 卷 期：2010年第20卷第4期

页      面：591-599页

核心收录：

学科分类：0710[理学-生物学] 081803[工学-地质工程] 07[理学] 08[工学] 0818[工学-地质资源与地质工程] 071004[理学-水生生物学] 

基　　金：provided by the National Natural Science Foundation of China (Nos. 50678182 and 40802001) the Natural Science Foundation of Chongqing City (No.2008 BA0015) the Research Fund for Teaching Reform in Institutes of Higher Learning, Chongqing, China (No.09-3-094) 

主　　题：Huaying Mountain Sanhuiba Xujiahe Formation member 2 sandbodies sedimentary characteristics reconsideration 

摘      要：The second member of the Triassic Xujiahe Formation in the Sanhuiba area in Huaying Mountain is an important section of sedimentary delta facies in the Chongqing Tianfu Geological Survey and Training Base. In spite of some initial efforts on its lithology and lithofacies, the existing research is yet to be completed and suffers from contradictory conclusions and inadequate evidence. Starting from the sedimentary microfaeies types and cyclic features, we analyzed the vertical sequence of a sedimentary delta model and discovered that this section is a constructional delta deposit. Eight incomplete and asymmetric regressive cycles are marked off, given that frequent erosion surfaces appeared in the section. Based on the analysis of structural characteristics of every monocycle, we summarized the system of cycles, tracts and sequence characteristics of the overall section. In view of this systematic series of cycles, we discussed the features of the syndepositional tectonic movements in the area and conclude that, due to frequent erosion, migration and diversion of a sub-channel branch was brought about by oscillating movements of the crust. In a comparison with neighboring sections, we explored the cause of erosion and the relations between erosion and cycles. This study greatly strengthens existing research and theories, makes an important and comprehensive contribution to geological surveys and training in the area and provides essential suggestions for coal exploration, oil and gas evaluation and in general to exploration and development in the target stratum.