摘要
皖南东至地区奥陶系在地层分区上可以分为下扬子地层分区、过渡地层分区和江南地层分区 ,在沉积相上可分为台地、斜坡与盆地沉积。通过对位于台地、斜坡和盆地露头层序地层的研究 ,分别将奥陶纪地层自下而上划分为 3个Ⅰ类沉积层序和 2个Ⅱ类沉积层序 ,并详细分析了每个沉积层序各体系域的特征。区内的奥陶系总体为一向上变深的沉积层序 ,经历了镶边陆棚—淹没台地—浅海盆地 3个演化阶段 ,其盆地呈北西浅。
The Ordovician in southern Anhui can be geographically divided into the Lower Yangtze, the transitional and the Jiangnan areas, and the depositions can be divided into the platform-type,slope-type and basin-type by the analyses of the sedimentary facies.Through the study of the outcrops in the platform ,slope and basin the disclosel sedimentary sequence of the Ordovicion strata can be divided into three first-order and two second-order sequences.The detailed analysis has been made for the features of the system domain of each sedimentary sequence and the stratigraphic sequence framework has been set up .Generally ,the Ordovician in this area is deposited in a basin that gradually become deeper with the changes of the strata from the bottom to the top of the sedimentary sequence, and the sea basin was of three evolutional stages: the rimmed shelf,the submerged platform and the shallow-sea basin.The basin appears to be deeper in the northwest and shallower in the southeast in depositional structural regime.
出处
《现代地质》
CAS
CSCD
2002年第1期45-52,共8页
Geoscience
