黔南独山石炭系层序地层及麦粒(竹蜓)带冰川型全球海平面变化

Carboniferous Sequence Stratigraphy and Glacio-Eustasy of Triticites Zone in Southern Guizhou, China

应用露头层序地层学原理和方法,对黔南独山地区碳酸盐岩为主的石炭系著名剖面进行了重新研究.识别出10个三级层序,其中岩关阶2个,大塘阶3个,威宁阶2个,马平组3个,大部分可以在台地和斜坡带追踪对比.在晚石炭世Triticites(Tr)带内识别出17个副层序和相应的海平面变化旋回,可以与北美中大陆同期17个四级层序和相应的海侵-海退旋回对比.黔南和北美中大陆之间存在相同的冰川型全球海平面变化和不同的构造背景,是出现上述现象的主要原因.

Based on the outcrop sequence-stratigraphic analysis of the typical Carboniferous carbonate sections exposed from southern Guizhou, 10 third-order sequences are examined in detail with particular attention to the key surface or the parasequence stocking pattern respectively. There are 2 sequences in Tournaisian (Datang), 3 in Visean -Early Namurian (Yanguan), 2 in Late Namurian-Westphalian (Weining )and 3 in Stephanian-Sakmarian (Maping). Most of these sequences can be correlated in various paleogeographic units and sedimentary fades. It should be pointed out that 17 fourth-order glacial-eustasy trans-gressive-regressive cycles of the Triticites zone are found both in the southern Guizhou and in the North American Midcontinent. In Midcontinent, these cydes are represented by fourth-order sedimentary sequences; but in the Southern Guizhou, only parasequences. Probably,the same eustasy and the different tectonic background are the main causes of above facts during the Stephanian.