A Novel Three-stage Tectonic Model for Mississippi Valleytype Zn-Pb Deposits in Orogenic Fold-and-Thrust Belts  

作　　者：SONG Yucai 

机构地区：[1]SinoProbe Laboratory,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China

出　　处：《Acta Geologica Sinica(English Edition)》2024年第4期843-849,共7页地质学报（英文版）

基　　金：funded by National Natural Science Foundation of China (Grant Nos. 42125204, 92155305, 42103068, 42372114, 42372115)。

摘　　要：Mississippi Valley-type(MVT) Zn-Pb deposits predominantly form within both orogenic forelands and fold-andthrust belts, yet the mineralization process within the latter tectonic setting remains inadequately understood. This study, through a comprehensive review of MVT deposits across global fold-and-thrust belts, introduces a novel model elucidating the mineralization process in the context of tectonic belt evolution. It is demonstrated that during the stage Ⅰ, regional compression is introduced by early stages of plate convergence, causing the folding and thrusting and creating structural or lithological traps such as evaporite diapirs and unconformity-related carbonate dissolution-collapse structures. Thereafter, in stage Ⅱ, hydrocarbons begin to migrate and accumulate within these traps, where reduced sulfur is generated through thermochemical or bacterial sulfate reduction concurrent with or preceding Zn-Pb mineralization. In the subsequent stage Ⅲ, as plate convergence persists, the regional stress transitions from compression to transpression or extension. Under these conditions, steeply-dipping extensional faults are generated, facilitating the ascent of metalliferous brines into early-formed structural or lithological traps. Precipitation of Zn and Pb sulfides occurs through the mixing of Zn-Pb-transporting fluids with pre-existing reduced sulfur or by interaction with hydrocarbons.

关 键 词：Mississippi Valley-type Zn-Pb deposits fold-and-thrust belts tectonic model structural or lithological traps extensional faults 

分 类 号：P618.4[天文地球—矿床学]