贵州喀斯特天坑的研究现状与展望

基于贵州特殊的地貌地形,采用野外实地勘察、文献数据统计分析法,并结合目前喀斯特天坑的研究报道,对贵州喀斯特天坑发育的地质背景、成因、类型及其分布规律现状进行总结,并对其发展趋势和研究方向提出了展望。结果表明:(1)贵州喀斯特天坑共有25个,按深度和形态规模分类,超级天坑有3个,大型天坑有2个,中型天坑有18个,小型天坑(直径和深度100 m以下)有2个;(2)贵州喀斯特天坑主要以早三叠统永宁镇组、夜郎组,三叠系下统罗楼组加紫云组和三叠系中统小米塘组加凉水井组的不等厚地层为主,包括三叠统厚层块状灰岩、中石炭统及下二叠统厚层块状灰岩地层;(3)贵州喀斯特天坑成因包括塌陷型和冲蚀型两类,以塌陷型天坑为主;(4)贵州喀斯特天坑主要分布于贵州中部、南部、西部以及西北部一带,呈现出从南向北、从西向东,天坑数量逐渐减少,规模由大到小,超级或特大型天坑主要分布于黔南一带。

Research status and prospect of karst Tiankengs in Guizhou Province

Guizhou Province is located in the southwest of China, east of the Yunnan-Guizhou Plateau, topographically high in the west and low in the east. It is near the southeast continental margin, part of the upstream ecotone of the Yangtze River and the Pearl River. It is an important ecological barrier for the upstream areas of the Yangtze River and the Pearl River. This region hosts typical karst landforms which are widely distributed and of various types, and geographically distinct. Karst carbonate rocks are dominant where karst Tiankeng developed well. Karst Tiankeng is a negative geomorphology, widely present in central, northwest and southern Guizhou Province, China. It is characterized by large number, wide distribution and strong stability of inner environments. Based on the special geomorphology and topography of Guizhou, combined with research reports of karst Tiankeng availlable, this work conducted field investigations and statistical analysis of literature data on this phenomenon. The purpose is to review the research status of the geological background, origin, types and distribution patterns of karst Tiankeng in Guizhou, and puts forward the prospect of its development trend and research direction. The results show that， (1) There are 25 karst sinkholes in total in Guizhou. According to the depth, shape and scale, they are categorized into 3 super sinkholes, 2 large sinkholes, 18 medium sinkholes and 2 small sinkholes (diameter and depth less than 100 m)； (2) In lithology, Guizhou karst Tiankeng is mainly composed of early Triassic Yongning town formation, Yelang formation, lower Triassic Luolou formation plus Ziyun formation and middle Triassic Xiaomitang formation plus Liangshuijing formation, including Triassic thick massive limestone, middle Carboniferous and lower Permian thick massive limestone； (3)The genesis of karst Tiankeng in Guizhou includes two types， collapse type and erosion type, and the former is primary； (4) This karst Tiankeng is mainly distributed in central, southern, western and northwestern Guizhou showing a trend of gradual decrease in number and scale from south to north and from west to east, and super or super-large Tiankeng concentrates in the south.