Modeling-based mineral system approach to prospectivity mapping of stratabound hydrothermal deposits: A case study of MVT Pb-Zn deposits in the Huayuan area, northwestern Hunan Province, China

Abstract

An in-depth analysis of the modelled mineral system is prerequisite for producing mineral prospectivity maps. Critical to this is the accurate analysis of key ore-controlling processes and their translation into mappable targeting criteria and their spatial proxies. A case study illustrating and implementing the mineral prospectivity based on the theory of mineral system for stratabound hydrothermal deposits in the Huayuan area, northwestern (NW) Hunan Province, China helps analyze and summary the important mineral system components and promote the subsequent mineral prospectivity mapping. In the light of a local Pb-Zn metallogenic model and regional metallogeny, the ore-bearing strata were deposited in a platform edge shoal-reef facies, which not only facilitated the formation of a fluid reservoir, but also provided organic matter for the thermochemical sulfate reduction and the space for the ore accumulation. The left-lateral strike-slip movement of the Huayuan-Zhangjiajie fault forming the NE-trending secondary tensional fractures provides channels for ore-fluid migration. Based on the aforementioned, the NE-trending syn-ore fractures and thick ore-bearing strata, are crucial mappable targeting criteria for the delineation of prospective area. By detail analysis of the Huayuan-Zhangjiajie fault movement mode and the ore-bearing stratoisohypse mapping, three prospective areas were delineated. Our study from the perspective of mineral system emphasizes the importance of syn-ore fault analyzing, lithofacies paleogeographic and stratoisohypse mapping in the prospecting of MVT deposits in this case study. The method procedure for mineral prospectivity adopted in this contribution is also suitable for the prediction of other stratabound hydrothermal deposits.