旋回频率曲线在幕式聚煤作用研究中的应用——以西南地区上二叠统为例  

THE APPLICATION OF DEPOSITIONAL CYCLE FREQUENCY CURVE TO EPISODIC COAL ACCUMULATION: WITH AN EXAMPLE FROM THE UPPER PERMIAN IN SOUTHWEST CHINA

作　　者：郝黎明[1] 邵龙义[1] 时宗波[1] 张鹏飞[1] 

机构地区：[1]中国矿业大学(北京校区)资源开发工程系,北京100083

出　　处：《古地理学报》2000年第4期12-19,共8页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金 (4 9772 12 9)资助项目

摘　　要：海平面的变化是旋回性沉积作用的重要控制因素。在克拉通盆地滨海平原沉积背景中 ,海岸线附近的沉积环境受海平面变化影响最为明显 ,旋回性沉积作用易留下证据。而在远离海岸线的内陆或滨外较深水地区 ,海平面的变化一般难以引起沉积环境的明显变化 ,因而其旋回性沉积作用不甚明显。反映在旋回的数量上 ,海岸线附近的旋回数目比远离海岸线地区的旋回数目要多得多。海岸线附近一般是最有利的聚煤场所 ,所以某一时期的旋回频率曲线中的峰值所在地区即是该时期聚煤中心所在位置。在三级海平面变化范围内 ,从低位、海侵到高位层序组 ,旋回峰值区会随着海平面的变化而变化 ,据此可以识别聚煤中心的迁移规律。本文在介绍了海平面变化与聚煤作用的关系及旋回频率曲线的方法原理基础上 ,利用旋回频率曲线法研究了西南地区晚二叠世的幕式聚煤作用 ,划分了不同级别的聚煤作用幕 ,识别出了不同时期聚煤作用幕的聚煤范围。此外 ,通过对比不同期次的聚煤作用幕 ,得出了不同期聚煤作用幕聚煤中心的迁移规律。依据高分辨率层序地层学原理 ,将贵州西部晚二叠世含煤岩系划分为 3个三级复合层序及 16个四级层序 ,每个三级复合层序中又分为低位、海侵和高位层序组 ,在此基础上 。Sea level changes are one of the important controlling factors for cyclic sedimentation. In cratonic coastal plain settings, depositional environments in the vicinity of the shoreline are very easily to be influenced by sea level changes, resulting in obvious cyclic sedimentation, while depositional environments far away from the shoreline, either landward or seaward, do not vary much with sea level changes. As a result, the cycles in the shoreline area show higher frequency than those in the area far away from the shoreline. Generally, the shoreline area is the favorable site for coal accumulation, so the area with the maximum number of depositional cycles is the coal accumulation center. Therefore, in a cycle frequency curve, the maximum frequency is corresponding to the coal accumulation center. However, location of this maximum frequency varies from lowstand, transgressive to highstand sequence sets in a third order sea level change. This variation allows us to identify migrating regularity of the coal accumulation center. According to the high resolution sequence stratigraphic analysis, the Late Permian in western Guizhou is subdivided into 3 third order composite sequences and 16 fourth order sequences, and each third order composite sequence is composed of lowstand, transgressive and highstand sequence sets. In this paper, cycle frequency curves corresponding to different sequence sets and different composite sequences are reconstructed and migrating regularity of the coal accumulation center are analyzed.

关 键 词：旋回频率曲线 幕式聚煤作用 层序地层学 晚二叠世 贵州 西南地区 

分 类 号：P512.2[天文地球—地质学] P618.11