河南木厂河区银、金、铜矿床的构造控矿特征

CONTROLS ON THE MUCHANGHE Ag-Au-Cu DEPOSIT,HENAN,BY DETACHMENT FAULTS

河南木厂河地区,位于秦岭—大别山中央造山带的东部,桐柏—大别构造亚带东段。区内以长期活动的NWW—近EW向深大断裂及派生的NWW向,SN向断裂以及平行于东部郯庐断裂带的NE向断裂为主要特征,褶皱表现为形态复杂的宽缓线形。通过调查研究,确认了木厂河矿区存在三个构造岩石单元:核杂岩单元(CC)、超高压单元(UHP)、高压单元(HP)。各单元之间发育有大型的拆离断层,有利于成矿元素富集。本区矿床的形成与大别山超高压变质带折返后的伸展拆离作用密切相关。矿体形成部位主要在核杂岩单元之上,超高压单元之下的拆离断层带。拆离断层对本区的矿化起了重要的控制作用。

The Muchanghe area, Shangcheng County, Henan Province, is tectonically located in the east of the Qinling-Dabie orogenic belt, in the eastern segment of the Tongbai-Dabie tectonic subbelt. The structure in the area is mainly characterized by long-active WNW-nearly E-W-trending deep faults and their derivative WNW- and N-S-trending faults, as well as NE-trending faults parallel to the Tanlu fault zone to the east. Faults are marked by complex, open linear folds. Geological survey has confirmed that there are three tecto-lithostratigraphic units in the Muchanghe ore district： the core complex unit （CC）, ultrahigh-pressure unit （UHP）, high-pressure unit （HP）, which are separated by large detachment faults. The activities of the detachment faults favored enrichment of ore-forming elements. The formation of the deposit in the area is closely related to extension and detachment following the exhumation of the Dabie UHP metamorphic belt. Most orebodies occur in a detachment fault zone above the CC unit and below the UHP unit. The detachment fault zones played an important role in controlling the mineralization in the area.