中国岩溶2017，Vol.36Issue(3)：296-305,10.DOI:10.11932/karst20170302
雪玉洞母岩沉积地质特征及其对次生沉积物的影响
Characteristics of sedimentary geology of parent rock at the Xueyudong Cave and its impact on secondary sediments
摘要
Abstract
The purpose of this work is to explore the effect of parent rock at caves on the cave system and its secondary sediments.Taking the Xueyudong Cave in Fengdu,Chongqing City as an example,we have made a detailed investigation to characterize its sedimentary geology,and study the relationship between sedimentary characteristics of parent rock and development of the cave and its secondary deposits.The results indicate that the parent rock of Xueyudong Cave belongs to the second member of Triassic Feixianguan Formation with main sedimentary facies as grain shoal.The main types of the rock are calcarenite grainstone,oolitic grainstone,calcirudite grainstone with a little micrite sandwiched.The predominant mineral compositions of the parent rock and secondary sediments are low magnesium calcite (LMC).The low Mg/Ca ratio of the parent rock led to a low Mg/Ca ratio of drip water in the cave,resulting in fast sideward growth of calcite crystals in LMC which are pure,coarse and of highly idiomorphic,that constitute the secondary sediments.The interbank,a relatively quiet sedimentary environment when the roof strata of the Xueyudong Cave were deposited,provided a good condition for the formation of thick-bedded limestone with high strength,thus helpful for development of the cave system.It means that the features of sedimentary geology of the parent rock in the cave can produce obvious influence on the evolution of the cave system and its secondary sediments.关键词
碳酸盐岩/沉积地质特征/次生沉积物/低镁方解石/雪玉洞Key words
carbonate parent rock/sedimentary facies/speleothem properties/low magnesium calcite/Xueyudong Cave分类
天文与地球科学引用本文复制引用
雷佳琪,伍坤宇,由超,姜雪萌,王鹏,蒋勇军..雪玉洞母岩沉积地质特征及其对次生沉积物的影响[J].中国岩溶,2017,36(3):296-305,10.基金项目
喀斯特槽谷区土地石漠化过程及综合治理技术研发与示范(2016YFC0502300) （2016YFC0502300）
