Proterozoic to Phanerozoic case studies of laser ablation microanalysis for microbial carbonate U–Pb geochronology  

作　　者：Yuxiang Jiang Simon V.Hohl Xiangtong Huang Shouye Yang 

机构地区：[1]State Key Laboratory of Marine Geology,School of Ocean and Earth Sciences,Tongji University,Shanghai 200092,China

出　　处：《Geoscience Frontiers》2024年第2期30-40,共11页地学前缘（英文版）

基　　金：We thank the National Science Foundation of China for funding S.V.Hohl with a Research Fund for International Excellent Young Scientists(RFIS-II),the stromatolite geochemical archive(funding no.42150610481)。

摘　　要：Some of the earliest bio-sedimentary records of life on Earth are represented by microbial carbonates,which are also critical geochemical archives of ancient seawater chemistry and the environmental circumstances in which they precipitated.Reconstructing paleo-microbial environments on Earth and potentially other planets requires precise determination of the depositional ages of these materials.The(abiogenic)carbonate geochemistry communities can now use developments in in-situ laser ablation U-Pb dating using inductively coupled plasma mass spectrometry(LA-ICP-MS).Due to the effects of impurity mixing and diagenesis,microbial carbonates have received little geochronological study despite their broad relevance for understanding ancient seawater’s environmental conditions and geochemical compositions.This study demonstrates using time-of-flight mass spectrometry(TOF-MS)to perform quick,quantitative elemental mapping before U-Pb spot dating to improve experiment success rates and data reliability and offers four practical application examples.

关 键 词：STROMATOLITE Microbial carbonate Carbonate geochronology In-situ LA-ICP-MS ICP-Time Of Flight-MS Trace element mapping 

分 类 号：P534[天文地球—古生物学与地层学] P581[天文地球—地质学] P597.3