塔里木盆地西南缘上石炭统米级旋回组构特征及层序地层研究

Upper Carboniferous Meter-Scale Cyclic Characteristics and Sequence Stratigraphy in the Southwestern Margin of Tarim Basin

在对塔里木盆地西南缘石炭系剖面研究的基础上,结合前人区域研究资料,用露头层序地层学方法对莎车县炮江沟上石炭统剖面进行了层序地层研究。结果表明:①塔里木盆地西南地区晚石炭世地层中发育大量碳酸盐岩米级旋回,以莎车县炮江沟剖面为代表,其主要类型有L-M型、深水非对称型、潮下型和环潮坪型;②塔里木盆地西南缘上石炭统中主要发育相对海平面快速上升所形成的淹没不整合型间断面,相对海平面快速下降所形成的暴露型间断面层序界面也有发现;③三级层序的不同体系域中发育不同类型的米级旋回序列,它们在垂向上有序叠加构成有规律的三级层序。

Based on previous results and detailed study on the profiles in the Southwestern Margin of Tarim Basin,the sequence stratigraphy in the Upper Carboniferous sections was addressed using the outcrop-based sequence stratigraphy.The results shows：（1） abundant carbonate meter-scale cyclic sequences occurs in carboniferous stratum of southwestern Tarin basin,and can be divided into four types：limestone-marl meter-scale cyclic sequence,deep-water asymmetric carbonate meter-scale cyclic sequence,subtidal carbonate meter-scale cyclic sequence and tidal flat carbonate meter-scale cyclic sequence.（2） the main sequence boundary found in carboniferous stratum of this area is drowned unconformity type,which was formed when relative sea level rise rapidly;while exposure type of sequence boundary can also be found,which was formed when relative sea level fall very fast.（3） different meter-scale cyclic sequences were developed within three different system domains and presents three-level cyclic sequences in the vertical dirction.