Geochemical characterization and application of apatite in magmatic rocks

Magmatic rocks may originate from different source regions and undergo complex magmatic evolutionary processes leading to changes in conditions such as magma composition, temperature and pressure. Apatite commonly occurs in magmatic rocks and can form in different magma environments. Apatite can contain a variety of geochemical indicator elements (e.g., rare earth element, strontium, manganese, and volatile elements, etc.) and is very sensitive to changes in host magmatic environments. Therefore, this mineral has been widely used in recent years in geological studies of magmatic rocks and associated mineral deposits. Understanding the mineralogical and geochemical characteristics of apatites in different rock types is the basis for in-depth related research. This article summarizes and categorizes the data on rare earth element in apatites from magmatic rocks reported in the GEOROC database and other literature and describes the mineralogical and rare earth element composition characteristics of apatites in different types of rocks. By combining multivariate statistical analysis methods, a thorough analysis is conducted on the variations in rare earth element in apatites from different types of magmatic rocks and granites. The calculated results show significant differences in the La content, Eu/Eu* ratio, and Yb content between apatites in different types of rocks. It is inferred that the combined use of the La content and (Eu/Eu*)/Yb ratio can effectively differentiate apatite that formed in different magmatic rocks. This study demonstrates the unique advantages of apatite in tracing magma source regions and rock genesis. The comprehensive analysis of apatite occurrence, associated mineral assemblages, trace elements, and isotopic compositions can provide comprehensive information for the study of magma rock genesis.