岩石矿物学杂志2024，Vol.43Issue(4)：918-930,13.DOI:10.20086/j.cnki.yskw.2024.0409
勐野井钾盐矿床中自生黏土矿物特征及其意义
Characteristics and significance of authigenic clay minerals in the Mengyejing potash deposit
摘要
Abstract
The Mengyejing potash deposit,which is located in the Simao Basin,Yunnan,contains different clastic rocks,namely greyish-green breccias coexisting with potash veins("green potash"),brownish-red breccias coexis-ting with potash veins("red potash")and yellowish-brown mudstones.XRD,SEM and TEM analyses were per-formed on those fine-grained clays extracted from clastic components.SEM and TEM observation suggests that those clay minerals are mainly composed of hexagonal,euhedral illites.It is very likely those illites are authigenic origin.The XRD results show that the"red potash"are composed of chlorite and illite,whereas both"green potash"and yellowish-brown mudstone contain"pararectorite"type clays,in addition to chlorite and illite.The Kübler values(indication of illite crystallinity)of the"red potash"range from 0.327 to 0.452° Δ2θ,which are much higher than those of the"green potash"and yellowish-brown mudstone(0.221 to 0.283° Δ2θ),indicating illites from the"green potash"and yellowish-brown mudstones have higher crystallinities than those from the"red potash".The"green potash"and"red potash"derived from the same provenance,and have undergone similar geologic processes.Thus the discrepancies with respect to clay assemblages and crystallinities among different clastic sediments were not merely caused by temperature and pressure.Previous studies have shown that the"green potash"were more re-ductive,imposed by more bacterial activities and had lower pH values,which are favourable to facilitate the crys-tallization of illite.关键词
勐野井钾盐矿床/自生黏土矿物/pH值/氧化还原条件/细菌作用Key words
Mengyejing potash deposit/authigenic clay minerals/pH values/redox conditions/bacterial activities分类
天文与地球科学引用本文复制引用
沈立建,彭强..勐野井钾盐矿床中自生黏土矿物特征及其意义[J].岩石矿物学杂志,2024,43(4):918-930,13.基金项目
国家自然科学基金项目(41802111,42272108) （41802111,42272108）
国家重点基础研究发展计划"973"项目(2011C403007) National Natural Science Foundation of China(42272108,42172083) （2011C403007）
National Key Project for Basic Research of China"973"(2011CB403007) （2011CB403007）
