内蒙古固阳渣尔泰山群层序地层学及其控制因素

渣尔泰山群是华北地台北缘中元古代裂陷槽沉积,主要为一套遭受绿片岩相区域变质的碎屑岩-碳酸盐岩建造。根据岩性、岩相、相序和不整合界面的综合研究,对这套地层进行了详细的层序界面分析和层序划分,识别出Ⅰ型、Ⅱ型和暴露-淹没复合型(Ⅲ型)3种类型层序界面,共划分出1个超层序、2个大层序和7个层序。总结了渣尔泰山群在碎屑滨岸、台缘碳酸盐岩与碎屑岩混积、碳酸盐台地、台前斜坡和陆棚盆地等不同古地理背景下的层序发育模式及其内部构成特征,并探讨了复合海平面变化、构造活动、沉积物供给、古地形等因素对层序形成和演化的控制作用。

SEQUENCE STRATIGRAPHY AND ITS CONTROLLING FACTORS OF THE ZHAERTAISHAN GROUP IN THE GUYANG DISTRICT OF INNER MONGOLIA

The Zhaertaishan Group was the aulacogen sediments deposited on the north margin of North China Platform during the middle Proterozoic Subera,consisting of mixed or interbedded detrital rocks and carbonate rocks.Based on the research of lithology,lithofacies,facies sequence and especially on the analysis of sequence boundaries,this paper describes the first-type,2nd-type and 3rd-type sequence boundaries in the Zhaertaishan Group in the Guyang district of Inner Mongolia,including exposure-drowning composite bounding surface and transgressive ravining surface.With different scale sequence boundary as bounding surface,the Zhaertaishan Group constitutes one supersequence,two megasequences and seven sequences.The models of sequence development and their internal constitution on the different paleogeographic settings such as detrital littoral, mixed carbonate and siliciclastic,carbonate platform and pre-platform basin have been established and the sequence controlling factors such as composite sea level change,tectonic activity, sediment supply and paleotopography have also been discussed in the paper.