华北晚古生代含煤岩系以层序古地理为背景的聚煤特征

Coal Accumulation of Coal bearing Formation of Late Paleozoic in the Background of Sequence Stratigraphic Paleogeography in North China Platform

华北晚古生代含煤盆地是我国最大的含煤盆地。笔者通过对盆内４９个典型剖面，５０个辅助剖面的环境分析，以及层序地层学研究，将其划分为Ⅰ—Ⅲ级层序及Ⅳ级准层序，共４级地层单元。Ⅳ级准层序相当副层序。一个Ⅳ级准层序内所含的煤体称为煤层。全区自晚石炭世至晚二叠世早期所限定的７个成煤期内，共圈出煤组７个，煤层２０层以上，以Ｂ３，Ｄ２，Ｇ７１煤层最具工业价值。Ｂ３煤层分布于盆地北部，Ｇ７１煤层分布于盆地南部，Ｄ２煤层全盆地均有分布。煤层聚积受多种因素控制。

Late Paleozoic coal bearing basin of North China is the largest in China.The analysis of the environment of 49 typical profiles and 50 auxiliaryprofiles in the basin and the study of sequence stratigraphy suggest that the coal bearing formation of Late Paleozoic in North China can be devided into sequence Ⅰ Ⅲ and parasequence Ⅳ,totally four stratigraphic units.Coal bodies accurring in parasequence Ⅳ are called seams.Within the seven coal forming periods restricted to from Late Carboniferous to early Late Permian,there are seven coal groups and more than 20 seams defined in the whole area,of which seams B 3,D 2and G 7 1 are economically important.Seam B 3 distributed in the northern part of the basin,G 7 1 in the southern part of it and D 2 in the whole area.Structural activities and fluctuation of sea level are the most important ones among the multiple coal accumulation controlling factors.