Characteristics of sedimentary geology of parent rock at the Xueyudong Cave and its impact on secondary sediments
LEI Jiaqi
WU Kunyu
YOU Chao
JIANG Xuemeng
WANG Peng
JIANG Yongjun
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.
Keywords：carbonate parent rocksedimentary faciesspeleothem propertieslow magnesium calciteXueyudong Cave
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 296-305 )