贵州六盘水地区早二叠世岩石地层之再认识

Re-understanding of the Early Permian Lithostratigraphy in Liupanshui Area,Guizhou Province

贵州六盘水地区早二叠世发育一套层序完整、相区分异明显的沉积记录。通过普立幅等1∶5万区域地质调查和前人对该区地层划分对比研究,认为其岩石地层划分仍有商榷之处。为了更好的反映研究区早二叠世岩石地层的时空展布关系,建立区域地层格架,本文将区内早二叠世地层拟定为三个岩石地层单位及三个非正式岩石地层单位:即龙吟组、包磨山组、平川组和薄板灰岩、鱼塘灰岩、肖坪灰岩。该成果对研究NW向裂陷槽早二叠时期在六盘水地区的充填序列、岩相古地理特征等提供了新的基础资料。

A set of sedimentary records with complete sequences and distinct facies were developed in Liupanshui area,Guizhou Province during the Early Permian.Based on the 1:50000 Puli regiongal geological survey and the previous studies in this area,it is considered that the division of lithostratigraphy is still open to discussion.In order to reflect the distribution of the lithostratigraphy and establish a regional framework,the Early Permian strata are divided into three rock stratigraphic units and three informal rock stratigraphic units in the study area:the Longyin formation,the Baomoshan formation,the Pingchuan formation and the thin plate limestone,the Yutang limestone,the Xiaoping limestone.The result provides new basic data for studying the fillingsequence and lithofacies palaeogeographic characteristics of the rifting trough in Shuicheng area during the early Permian period.