贵州南部泥盆系层序地层划分和层序地层格架的建立

贵州南部的泥盆系为一个大型的楔状体。从深水背景的广西南丹罗富剖面到古陆边缘的贵阳乌当剖面,泥盆系由13个层序变薄尖灭成5个层序,这是泥盆纪早期海侵尖灭与晚期海退尖灭的结果。研究区泥盆系由海侵碎屑岩岩系到清水台地碳酸盐岩岩系地层序列构成2个二级层序,又可进一步划分为13个三级层序。二级层序和三级层序均由其特殊的沉积相序列组成。研究区泥盆系层序地层划分和层序地层格架的建立提供了一个在年代地层与海平面变化框架内研究“相迁移”的良好实例。

Devonian sequence stratigraphic classification and establishment of the sequence stratigraphic framework in southern Guizhou, China

The Devonian in southern Guizhou occurs as a large sedimentary wedge. From the deep-water facies of the Luofu section of Nandan, Guangxi, to the neritic facies of the Wudang section of Guiyang, the Devonian sequences change from 13 to 5 in number, which resulted from the earlier transgressive pinch-out event and later regressive pinch-out event during the Devonian. The Devonian displays a succession consisting of transgressive clastic sedimentary rocks in the lower part, mixture of clastic sedimentary rocks and carbonate rocks in the middle part and carbonate rocks in the upper part and may be divided into 2 second-order sequences and 13 third-order sequences. The second-order and third-order sequences are both composed of special sedimentary facies successions. The sequence stratigraphic division of the Devonian and establishment of the Devonian sequence stratigraphic framework provide a good example for the study of the "facies shift" in the chronostratigraphic and sea-level change framework.