广东省二叠纪含煤岩系层序地层特征

Permian Coal-bearing Strata Sequence Stratigraphic Features in Guangdong Province

根据野外剖面实测、室内岩矿鉴定及综合作图等,对广东省二叠纪含煤岩系层序地层特征进行分析,识别出区域不整合面、下切谷冲刷面、古土壤层、事件界面、沉积相转换面5个类型、共6个三级层序界面,划分为5个三级层序。S1～S5各层序底界面的代表界面分别为广花地区K1砂岩底面、广花地区K2砂岩底面、连阳地区灰岩不整合面、连阳地区白灰岩段底面和广花地区圣堂组大套砂岩底面;S5的顶界面为二叠系与三叠系之间的构造事件面。对比不同地区后发现,广花和兴梅两个地区的层序发育特征较为类似,连阳地区5个层序的变化呈现了海侵(S1、S2)-快速海退-海侵(S3)-缓慢海退(S4、S5)的旋回过程,而曲仁地区的5个层序特征类似、变化较小。与20世纪90年代层序地层划分方案对比,有2个层序界面与本次划分的层序界面相同。

Based on field measured sections, indoor rock and mineral identification and comprehensive mapping, have analyzed Permian coal-bearing strata sequence stratigraphic features. 5 types of regional surface of unconformity, incised valley scour surface, fossil soil bed, event interface and sedimentary facies transformation base have been identified, totally 6 third-order sequence boundaries and divided into 5 third-order sequences. Representative interfaces of S1～S5 bottom have K1 and K2 sandstone bottoms in the Guanghua area, limestone unconformity surface and white limestone member bottom in the Lianyang area, as well as the Shengtang Formation Datao sandstone bottom in Guanghua area; top interface of $5 is the structural event interface between Permian and Triassic systems. The contrast of different areas has found that the sequence development features in Guanghua and Lianyang two areas are rather similar. The variation of 5 sequences in Lianyang area presents cyclic process of marine transgression （S1, S2）-fast regression-transgression （S3）-slow regression （S4, S5）, while 5 sequences features in the Quren area are similar but little varying. The contrast between 1990s＇ sequence stratigraphic division scheme and this study, 2 sequence interfaces are identical.