Geochemical Characteristics and Geological Significance of the Husite Pluton in Kekesala, West Tianshan

The Husite pluton serves as the ore-forming rock body of Kekesala Fe-Cu deposit, which is composed of quartz diorite, granodiorite, monzogranite and orthoclase granite. All of their ages are Late Devonian. This pluton has SiO₂ content of 63.30%~69.16%, with high alkali content, rich potassium and low sodium (average K₂O+Na₂O content of 7.28%; average K₂O/Na₂O ratio of 1.08), belonging to quasi-aluminum and weakly peraluminous, high-K calc-alkaline series. This pluton has high LREE/HREE ratio (averaging in 8.32) and has negative Eu anomalies (δEu=0.45~0.79, with an average value of 0.71). It is rich in large ionic lithophile elements (LILEs:Rb, Th, K, Zr and Hf), but is depleted in high strength elements (HFSEs:Nb, Ta, Ti), showing the characteristics of volcanic arc granite. No post-orogenic or intracontinental granite with an age of 295 Ma (molybdenite Re-Os age) has been found in this area. Therefore, the geochemical characteristics of the Husite pluton can prove that the age of this pluton serves as the only basis for indirectly providing the ore-forming age of the Keshala iron-copper deposit. The Early Permian Mo mineralization and Keshala iron-copper mineralization in the area should be the products of two metallogenic events.