Applications of trace element and isotope geochemistry in revealing origin and evolution of thermal spring water and ore deposit

Abstract

Geochemistry is normally referred to as the study of Earth’s chemistry by exploring properties of materials and natural processes from deep beneath the Earth’s surface to the upper atmosphere, demonstrating the natural phenomena nowadays and discovering the history of nature. This study describes a subtopic of geochemistry: inorganic isotopes and trace elements, and discusses the application of the isotopes and trace elements in studies of geothermal spring water and ore deposit. The study of water samples in Hengjing, China was accomplished with the help of gas isotope analysis. The carbon isotope ratios and gas compositions indicate that the thermal waters are mostly sourced from meteoric and mantle sources in this area. The He isotope could evolute from mantle fluid, and CO2 is a product of the carbonate decomposition of rocks at high temperatures. The other study, conducted on the Zhaoxian ore deposit, revealed the origin and processes of formation of the different compositions of the ore. The magmatic-hydrothermal activity in this tectonically active area contributes much to the mineralization process of the ore, as shown by the analysis of trace elements of pyrite. The fluid inclusion He-Ar isotope shows that the ore was characterized by crust-mantle mixing with a little participation of meteoric water.