摘要
作者对贵州丹寨—三都中上寒武统两个碳酸盐岩露头剖面进行了层序地层学研究 ,识别出 5个 (三级 )层序。其中 ,寒武系顶界和都柳江组中部有Ⅰ型层序边界 ,其余为Ⅱ型层序边界。论述了该区构造演化史 ,指出由于构造升降运动 ,两露头剖面的沉积环境发生变化。受海洋物理化学条件的控制 ,碳酸盐岩生产率以及生物种群显著变化 ,在一定程度上影响了碳酸盐岩台地的堆积。诸多因素都对碳酸盐岩地层层序或沉积相在横向上和纵向上的展布和排列形式有重要的控制作用。在寒武纪时 ,区内有两个沉积模式 :一为广阔的坡缓底平的广海陆棚模式 ,形成于早寒武纪 ;二为台地 (斜坡 ) -广海 (盆地 )沉积模式 ,形成于中晚寒武纪。
The essay studies the sequence stratigraphy of two Upper-Middle Cambrian outcrops in Danzhai-Sandu, Guizhou, and definitely identified five sequences of three-grade. Among them, there existⅠ-type sequence boundaries either at the top of the Cambrian or in the middle of the Duliujiang formation, the others are Ⅱ-type sequence boundaries. It expounds the tectonic evolution in the area and points out that the depositional environments of two outcrops are changed because of the activities of tectonic fluctuation. Under the control of marine physicochemical condition, the productivity of carbonate rocks and the biological population alter remarkably so as to influence the accumulation process of carbonate platform to a certain extent. Many terms behave as the important control action for the carbonate succession of strata or the distribution and the rank forms of the sedimentary facies in horizontal and vertical. During the Cambrian period, two sediment models in this zones are: 1) broadly open sea shelf type with ramp platform and flat floor, which shaped in early Cambrian; 2) platform (or ramp)-open marine (or basin) sediment model, which formed in upper-middle Cambrian.
出处
《贵州地质》
2002年第4期242-248,共7页
Guizhou Geology
