沉积与特提斯地质2025，Vol.45Issue(1)：120-133,14.DOI:10.19826/j.cnki.1009-3850.2024.11003
热液导致的白云石重结晶过程中的原位地球化学记录:以塔里木盆地巴楚地区上寒武统白云岩为例
Evolution of in-situ geochemical records in hydrothermal recrystallization of dolomite:A case study from Upper Cambrian dolostones in the Bachu area,Tarim Basin
摘要
Abstract
The Upper Cambrian dolostones in the Tarim Basin have undergone widely alteration by hydrothermal fluids.In this study,based on petrological and trace element analyses,three types of dolomites were identified in the Upper Cambrian dolostones of Well BT5 in the Bachu area:matrix dolomites(MD),dolomite cements with cathodoluminescence zonation(SD1),and blocky dolomite cements(SD2).SD1 occurs as euhedral crystals,consisting of a core(SD1-1)and a rim(SD1-2).SD1-1 is characterized by cloudy crystal surfaces and bright red luminescence under cathodoluminescence(CL),while SD1-2 displays bright crystal surfaces with irregular bright-dark zoning under CL.And SD2 exhibits wavy extinction and shows bright red under CL.From the host dolostone(MD)to the last generation of dolomite cements(SD1,and SD2's core SD2-1),the Sr concentrations decreased,and the total rare earth element concentrations(ƩREE)as well as light rare earth element enrichment increased.Consequently,SD2-1 is interpreted to be dolomite fillings precipitated from hydrothermal fluids,while SD1 results from hydrothermal recrystallization of MD.This study suggests that the dolomites formed from hydrothermal recrystallization show transitional REE characteristics,which can serve as a useful tool to identify recrystallization process in dolomites.关键词
塔里木盆地/上寒武统/白云岩/热液重结晶/微量和稀土元素Key words
Tarim Basin/Upper Cambrian/dolostone/hydrothermal recrystallization/trace and rare earth elements分类
地质学引用本文复制引用
刘明铭,鲁子野,李飞,陈曦,叶宁,黄柏文,李映涛,张歆妍,张哨楠..热液导致的白云石重结晶过程中的原位地球化学记录:以塔里木盆地巴楚地区上寒武统白云岩为例[J].沉积与特提斯地质,2025,45(1):120-133,14.基金项目
国家自然科学基金项目(42102191) （42102191）
