Subsurface structures of the Xiaorequanzi deposit, NW China: new insights from gravity, magnetic and electromagnetic data

Abstract

ABSTRACTThe Xiaorequanzi copper–zinc deposit, located in the eastern Tianshan, is considered as a medium‐sized polymetallic deposit in Xinjiang, NW China. Understanding the structural framework and delineating the location of intrusions as well as the distribution of ore‐controlling strata in this mining area are vital for identifying new potential exploration areas. This paper aims to provide new information on the subsurface structures of the Xiaorequanzi copper–zinc deposit and to explore new target area for the ore prospecting based on comprehensive interpretation of multiple geophysical datasets. Several potential field filtering methods were used to study the spatial distribution of the geological structure. The structural lineament was delineated based on various source boundary detection results. Euler deconvolution method was used to estimate the field source depth, and the structure model was constructed from 2.5D forward gravity modelling, constrained by borehole and electromagnetic data. The results indicate that the local gravity highs may be the concentration of mineralized rocks with high density extending to depths of several hundred meters; the magnetic highs are related to mineralized rocks/intrusive rocks that are close to the surface. The tectonic framework of the whole ore bed is mainly controlled by NW‐SE, E‐W and NE‐SW structures, in which NE‐SW structures are related closely to mineralization and may provide optimum conditions for magma emplacement and fluid migration. Our research will help to study the tectonic evolution and guide further exploration of the deposit.