贵州南部二叠系层序地层格架

通过对贵州南部典型的二叠系剖面(包括石炭系上部的地层)的层序地层研究,共识别出7个三级沉积层序,在对不同相带剖面三级层序对比的基础上建立了贵州南部二叠系的层序地层格架。该二叠系层序地层具有以下明显的特征:在连陆台地上发育煤系地层,连陆台地边缘则发育海绵生物礁和颗粒滩,相分异最明显的时期正好与生物礁发育的时期相对应;此外,在二叠系与三叠系之交发生了大规模的台地淹没事件,因此,二叠系最顶部的三级层序的顶界面为一个典型的淹没不整合面。在二叠系层序地层格架图中较明显地表现出复杂而有序的时间和空间相变。

THE PERMIAN SEQUENCE-STRATIGRAPHIC FRAMEWORK IN SOUTHERN GUIZHOU

Based on the sequence stratigraphic divisions of the typically several sections that are developed in different paleogeographical backgrounds, 7 third order sequences could be discerned in Permian strata including the top part of Carboniferous system. The sequence stratigraphic framework dearly reflects the sophisticates and regular facies changes in time and space, in which also shows lots of features: in the connective platform are coal measures developed, in the margin of the connective platform are sponge reefs and grain beaches developed , and developmental periods of reefs are corresponded to the formation period of sedimentary facies differentiation. The large scale drowned event of the carbonate platforms in the transitional period from Permian to Triassic leads to the formation of a drowned type of sequence boundary that is the top boundary of the top sequence of Permian.