中国岩溶2024，Vol.43Issue(6)：1430-1444,15.DOI:10.11932/karst20240619
云南麻栗坡老山地区岩溶地貌地质遗迹特征及成因分析
Features and genesis analysis of geological relics of karst landforms in the Laoshan area of Malipo,Yunnan Province
摘要
Abstract
The Laoshan area in Malipo,Yunnan Province is located in the transitional zone from the karst plateau in southeastern Yunnan to the Red River Delta Plain in Northern Vietnam,where the gorge-type karst landform is typically developed,forming a rich and diverse set of geological relics of karst landforms.These relics play an important connecting role and are typical representatives in the evolution process of karst landforms in Southwest China and Southeast Asia.Since 2013,the development of the scenic area named"Heroic Laoshan Sacred Land"has prominently featured nature sightseeing tours centered around geological relics of karst landforms.Surveys have found 47 typical geological relics in this area,characterized by cave groups,canyon groups,waterfall groups,peak-cluster depressions,and peak-cluster valleys.However,the existing data indicates that this area primarily focuses on the investigation and research of mineral resources,and structural and rock unit systems.In contrast,there is a significant gap in understanding the unique geological relic characteristics and composition of subtropical canyon-type karst landforms,as well as their spatial distribution,and evolutionary causes,which are critical issues.This lack of understanding has affected high-quality development and reasonable protection,and there is an urgent need for further research and discussion.Therefore,based on the investigation of karst landform geological relics,it is essential to enhance studies on the characteristics and genesis analysis of geological relics in the study area.These studies are of practical significance for revealing the formation and evolutionary mechanisms of the typical areas developed with karst landforms that transition from the karst plateau in southeastern Yunnan to the plains of the Northern Vietnamese Delta.Additionally,these studies will contribute to the economic development of border area tourism and the prosperity of the border area and its inhabitants. This article analyzes the distribution and developmental characteristics of geological relics of karst landforms in the study area,examines the causes of their formation,and,based on previous research findings,discusses the formation and evolutionary mechanisms of typical canyon karst landforms in Yunnan.The results show as follows.(1)The study area boasts a rich variety of geological relics of karst landform,including surface karst landforms,subsurfaces karst landforms,transitional karst landforms and hydrological landforms.Surface karst landforms include peak clusters,depressions,karst gorges,clints,grikes and karstic traces.Subsurface karst landforms consist of karst caves,underground rivers,and various depositional forms.The transitional karst landforms from surface to subsurface are represented by small-scale karst collapse doline groups that are locally exposed.Hydrological landforms include karst waterfalls and karst springs.(2)The study area is characterized by gorge-type karst landforms,with developed karst caves that exhibit stratification.The types of caves and depositional forms at different levels are similar,with low-altitude caves being a distinctive feature.They can be divided into five levels:>1,750 m,1,200-1,600 m,600-1,000 m,200-500 m,and<150 m.The main types of caves are dry caves,water-out caves,water-in caves,and their mixed types.In the karst dry caves,there is a significant amount of collapse debris of original rock or sandy silt blocking the cave passages,and secondary chemical sediments are generally underdeveloped.There are few large cave halls in the caves,and medium to large-scale caves represented by Qingliang cave and Mangun cave are characterized by different traces and different periods of structures overlapping and interacting with each other and by double-layered development.Several caves with convenient transportation show clear signs of human activities,but the most remain in their pristine states.(3)The Wenshan-Malipo NW-trending left-lateral strike-slip fault zone significantly influences the formation and evolution of geological relics of karst landforms.The geological relics of karst landforms are mainly distributed in a northwest to southeast strip along the karst gorge of the Nanwen river.The multi-stage uplift of neotectonic movements also has significantly impacted the formation of karst landforms.The continuous deposition,stable stratification,and extensive distribution of Cambrian,Devonian,and Permian carbonate formations,characterized by significant depositional thickness in the study area create optimal material conditions for the formation and development of geological relics.These factors also control the regional distribution of these relics.At the same time,the study area is located in the subtropical monsoon climate zone,south of the Tropic of Cancer,where the unique climate and hydrological conditions have a significant impact on the formation of karst landforms.The abundant atmospheric precipitation provides ample water sources for the karstification process in this area.(4)Based on previous research findings and comparison of regional elevations,landform morphologies,individual morphological characteristics of karst landforms in the study area,as well as the conditions for the formation of different landform combinations,the genesis and evolutionary process of geological relics of karst landforms in the study area since the Late Mesozoic can be preliminarily divided into two stages:the formation of the tectonic basin during the Yanshan Period and the crustal differential uplift during the Himalayan Period.关键词
岩溶地貌/地质遗迹/成因分析/麻栗坡/云南Key words
karst landform/geological relics/genesis analysis/Malipo county/Yunnan Province分类
天文与地球科学引用本文复制引用
潘天望,史文强,李成展,陈伟海,唐亮亮,武红梅..云南麻栗坡老山地区岩溶地貌地质遗迹特征及成因分析[J].中国岩溶,2024,43(6):1430-1444,15.基金项目
中国地质调查局项目"渝东南地区岩溶地貌地质遗迹立典调查评价"(DD20242325) （DD20242325）
中国地质科学院岩溶地质研究所基本科研业务费"重庆金佛洞望天宫冰洞成景机制研究"(2023005) （2023005）
