Geochemical Indicators of Sedimentary Environments—A Summary

With the use of geochemical methods,by studying the characteristics of major and trace elements and element isotopic characteristics,the ancient sedimentary environments can be rebuilt,so as to define their sedimentary facies.Marine facies or continental facies and their paleosalinities can be determined and detected in terms of Sr/Ba ratios,borium contents-O isotopes and so on;the contents of specific elements(such as P,Sr) and element ratios(such as Sr/Cu,Mg/Ca) under particular climate conditions are the indicators of that climate;redox sensitive elements(such as Mo,U,V,Ni,Ce and Eu) are the best recorders of redox conditions;because of differences in element migration ability,the determination of water depths and the fluctuations of sea level can be made from element associations(such as Fe group,Mn group),element ratios(such as Sr/Ba,Sr/Ca) and isotopes(87Sr/86Sr).Thus,we can also identify their provenances,source rocks' lithologies and tectonic settings,as well as hydrothermal deposition or not.