印支运动的沉积学响应——以湖北秭归盆地中、上三叠统为例  

Sedimentary response to the Indosinian movement-a case study of the Mid-Upper Triassic in the Zigui basin, Hubei

作　　者：李旭兵[1] 王传尚[1] 刘安[1] 

机构地区：[1]宜昌地质矿产研究所,湖北宜昌443005

出　　处：《中国地质》2008年第5期984-991,共8页Geology in China

基　　金：中上扬子海相含油气盆地分析与油气成藏条件综合调查评价项目(121010733505)资助

摘　　要：通过对秭归盆地南缘中、上三叠统巴东组和沙镇溪组地层剖面的实测及1∶10万秭归幅地质填图发现,中三叠统巴东组在秭归盆地东南缘存在不同程度的缺失,秭归郭家坝一带,只沉积巴东组一段、二段地层。秭归楠家湾一带,整个巴东组全部缺失,上三叠统沙镇溪组直接覆盖于早三叠世嘉陵江组之上。而秭归盆地西缘沙镇溪、巴东麂子岩一带,巴东组发育齐全。上述现象表明,在早三叠世末期,由于印支运动的影响,巴东组地层出现了较大差异。沙镇溪组在沉积上继承了巴东组高低不平的古地貌特征,沉积厚度变化较大。上三叠统沙镇溪组与中统巴东组之间,在盆地不同的部位可呈现出整合或平行不整合的接触关系,而不存在断层接触关系。The authors made measurements of sections of the Middle-Upper Triassic Badong and Shazhenxi Formations on the south margin of the Zigui basin and 1：100,000 geological mapping of the Zigui Sheet and found that the Middle Triassic Badong Formation is missing to different degrees on the southeastern margin of the basin and that only the first and second members of the formation were deposited in the vicinity of Guojiaba, Zigui. The whole Badong Formation is absent in Nanjiawan; as a result, the Upper Triassic Shazhenxi Formation directly rests on the Lower Jialin^iang Formation. However, the Badong Formation is complete in Shazhenxi and Jiziyan on the western margin of the basin. The aforesaid phenomena indicate that there occurred appreciable difference in the Badong Formation because of the influence of the Indosinian movement at the end of the Early Triassic. The Shazhenxi Formation, varying greatly in thickness, inherited the characteristics of rugged ancient landforms of the Badong Formation when it was deposited. The authors suggest that the Middle Triassic Badong Formation and Late Triassic Shazhenxi Formations in different areas of the basin are not in fault contact but in conformable or disconformable contact.

关 键 词：三叠系 巴东组 沙镇溪组 秭归盆地 

分 类 号：P512.2[天文地球—地质学]