高原型喀斯特主要丘陵类型、形成机制与贵州喀斯特地貌分区刍议

Major Types and Formation Mechanism of Karst Hillin Plateau and Discussion on Karst Landform

喀斯特地貌类型和分区受气候、构造、地质背景等多种因素影响,仅以峰林、峰丛等形态组合为基础的地貌分区,难以完全反映贵州复杂的喀斯特地貌。以往的分区工作忽略了除典型锥峰、塔峰外大量分布的“馒头山”丘陵(穹丘)的重要性,其形态特征、空间分布以及形成演化机制等尚不清楚。本文根据贵州喀斯特地貌野外考察结果,结合室内资料综合分析,探讨了贵州不同喀斯特丘陵类型的空间分布规律、形成机制以及与气候、地质(岩性和岩相)等环境背景的内在联系,并结合已有石漠化分区方案,初步提出贵州高原喀斯特地貌分区方案。主要认识如下:(1)锥峰、塔峰、穹丘喀斯特丘陵和常态山非喀斯特丘陵是贵州高原主要的四种丘陵类型。(2)锥峰、塔峰的形成受表层岩溶带溶蚀机制控制,穹丘坡地形态与土壤蠕移有关。(3)贵州除非喀斯特区外,喀斯特区分为锥峰、塔峰喀斯特地貌区,穹丘喀斯特地貌区和喀斯特峡谷地貌区三个大区。(4)锥峰、塔峰喀斯特地貌区包含黔中西部北亚热带浅碟型峰丛(锥峰)洼地区和黔南南亚热带漏斗型峰丛(锥峰、塔峰)洼地区两个亚区。(5)穹丘喀斯特地貌区包含黔东北中亚热带褶皱构造穹丘槽谷区,黔北中亚热带不纯碳酸盐岩穹丘洼地区,黔西北暖温带穹丘洼地、盆地区,黔西西南季风常态山、穹丘洼地、盆地区,黔中东部北亚热带不纯碳酸盐岩穹丘-常态山洼地区五个亚区。(6)喀斯特峡谷地貌区为北盘江深切峡谷多丘陵形态立体分布区。本研究可为喀斯特地区生态建设、区域经济社会高质量可持续发展等提供科学依据。

The definition of karst landforms and zoning were governed by various factors,such as climate,tectonics,geology;however,if a topographical division of karst landform in Guizhou,China was outlined merely based on a simple morphological combination of peak-forest and peak-cluster,it must be not fully interpret the complexity of local karst geomorphology.Previous attempts to karst landform zoning ignored the fact that there are widely dome karst landforms except typical cone and tower karst,which was not well aware of and short of knowledge of morphological features,spatial distribution and formation and evolution mechanism.In this study,it investigated the distribution,formation mechanism in connection with the geo-environmental circumstances(climate,geology(lithology,lithofacies))of different karst hill areas in Guizhou.It conducted field surveys,indoor testing and finally tentatively proposed a updated scheme of karst geomorphology zoning for Guizhou with full reference to past research achievements in karst landform zoning scheme.Conclusions are listed as follows:(1)There were four major hill types of karst plateau in Guizhou,which were cone,tower,dome karst hills and normal hills(non-karst hills),separately.(2)The formation of cone and tower karst was controlled by chemical erosion of runoff in the epikarst zone.The formation of dome karst was subjected to soil creep.(3)Except non-karst area,karst area in Guizhou was initially divided into three landform zones:cone and tower karst,dome karst,and karst valley.(4)The cone and tower karst zone was divided into two geomorphology subzones which are the north subtropical fengcong(cone karst)depression region of shallow dish type in the west of central Guizhou,and the southern subtropical fengcong(cone and tower karst)depression region of funnel type in the south of Guizhou.(5)The dome karst geomorphology zone was divided into five geomorphology subzones which were middle subtropical dome karst trough valley region of the fold structure in the Southeast Guizhou;middle subtropical dome karst depression region of impure carbonate rocks in northern Guizhou;warm temperate dome karst depression and valley region in the northwest of Guizhou;southwest monsoon normal hills,dome karst,depression and basin region in the western Guizhou;north subtropical dome karst-normal hills depression region of impure carbonate rocks in the east of the middle Guizhou.(6)The karst valley geomorphology zone was divided into vertical distribution region of multiple hills in the deep valley of the North Pan River.This research can provide a scientific basis for high-quality ecological construction and sustainable development of regional economy and society in karst areas of China.