贵州中坪地区上三叠统二桥组砂岩粒度分析及其沉积环境意义  

SANDSTONE GRAIN SIZE ANALYSIS OF UPPER TRIASSIC ERQIAO FORMATION IN ZHONGPING AREA,GUIZHOU PROVINCE:Implication of Sedimentary Environment

作　　者：王宁祖 张文斌 何碧 陶刚 赵飞 孙平原 张志玺 赵振琯 WANG Ning-zu;ZHANG Wen-bin;HE Bi;TAO Gang;ZHAO Fei;SUN Ping-yuan;ZHANG Zhi-xi;ZHAO Zhen-guan(School of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China;No.2 Geology and Minerals Exploration Institute,Gansu Bureau of Geology and Mineral Exploration&Development,Lanzhou 730000,China;School of Environment and Resources,Southwest University of Science and Technology,Mianyang 621010,Sichuan Province,China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]甘肃省地质矿产开发局第二地质矿产勘查院,甘肃兰州730000 [3]西南科技大学环境与资源学院,四川绵阳621010

出　　处：《地质与资源》2023年第4期406-417,共12页Geology and Resources

基　　金：中国地质调查局项目“乌蒙山区地质矿产综合调查”(DD20160019);“贵州乌蒙山区1∶5万店子场(G48E006018)、大关(G48E007017)、六厂(G48E007018)3幅区域地质调查”(DD20160019-04).

摘　　要：通过对贵州中坪地区上三叠统二桥组16件砂岩样品进行粒度分析,结合二桥组砂岩地层所在的区域地质背景,研究砂岩形成时的沉积环境及水动力情况.对砂岩的粒度概率累计曲线、C-M图、粒度特征参数、结构参数散点图解等的分析显示,二桥组砂岩粒度概率累积曲线图具有较好的正态分布特征,频率直方图多呈单峰式;正态概率累计曲线主要为多跳一悬式、一跳一悬式、一跳一悬夹过渡式,主要由悬浮组分和跳跃组分组成,缺少滚动组分.中坪地区上三叠统二桥组从下部到上部处于一个由三角洲平原及前缘相向浅湖相过渡的沉积环境.Through the grain size analysis of 16 sandstone samples from the Upper Triassic Erqiao Formation in Zhongping area of Guizhou Province,combined with the regional geological setting,the paper studies the sedimentary environment and hydrodynamic conditions during the formation of the sandstone.The analysis on the probability cumulative grain size curves,C-M diagram,grain size characteristic parameters and scatter diagram of structure parameters of the sandstone indicates that the probability cumulative grain size curves of the sandstone from Erqiao Formation show good normal distribution,and the frequency histograms mostly show single-peak curves.The normal probability cumulative curves are mainly multi-bouncing population-one suspension population,one bouncing population-one suspension population,and one bouncing population-one suspension population-transitional zone patterns,mainly composed of suspended and jumping components,but lack of rolling components.The Upper Triassic Erqiao Formation in Zhongping area from the lower to the upper part is in a sedimentary environment transitioning from delta plain and delta front facies to shallow lake facies.

关 键 词：上三叠统 二桥组 粒度分析 沉积环境 贵州省 

分 类 号：P585.2[天文地球—岩石学]