Provenance and Tectonic Evolution of Bauxite Deposits in the Tethys: Perspective From Random Forest and Logistic Regression Analyses

Abstract

AbstractDevelopments in Earth system research have led to widespread interest in multi‐sphere interactions that may have controlled bauxite formation. Although karst bauxite ores are abundant in the Tethyan Metallogenic Domain (TMD), their genesis and distribution are not yet fully understood. This study utilizes the Random Forest (RF) model to analyze geochemical data sets compiled from three bauxite provinces in the Tethys, including the Mediterranean, Central Asian, and Chinese provinces. Meaningful variables among the provenance, paleolatitude and tectonic setting that affected the formation of the bauxite deposits are identified. The Logistic Regression model is used to verify the importance of various factors. Our study shows that when RF model achieves the best classifier performance, TiO2 is the variable that has the greatest impact on the model. TiO2 content is the highest in the Central Asian Province. The high TiO2 content in bauxites indicates a provenance of magmatic origine associated with the Subduction Provenance Zone. Bauxites with TiO2 content similar to that of the continental basement are derived from siliciclastic and carbonate rocks, identified as the Orogenic Provenance Zone. This study illustrates a novel link between geochemical compositions (TiO2 content) of bauxites, provenance and regional tectonic setting.