Fluid Evolution and Metallogenic Dynamics during Tectonic Regime Transition: Example from the Jiapigou Gold Belt in Northeast China

Autor: Jianping Wang, Jun Deng, Chunying Guo, Qingfei Wang, Bangfei Gao, Zhongshi Sun, Liqiang Yang
Rok vydání: 2009
Předmět:
Zdroj: Resource Geology. 59:140-152
ISSN: 1751-3928
1344-1698
DOI: 10.1111/j.1751-3928.2009.00086.x
Popis: The Jiapigou gold belt, one of the most important gold-producing districts in China, is located in the northern marginoftheNorthChinaCraton(NCC).ThetectonicevolutionofthegoldbeltiscloselyrelatedtotheSiberian Plate (SP) in the north, Yangtze Craton (YC) in the south and Pacific Plate in the east. In order to investigate the nature of the tectono-fluid-metallogenic system, the authors investigated the relationships among the tectonic regimes,fluidevolutionandmetallogenesis.Thispaperexaminedthecorrespondingspatial‐temporalrelationship between the ore-controlling tectonic regime and hydrothermal fluid evolution in the Jiapigou gold belt. Therearetwotypesofgoldmineralization:disseminatedoresthataredistributedwithintheNW-trendingmain ductile shear zone and gold-bearing quartz veins and minor disseminated ores that are distant to the ductile shear zone. The fluid inclusions in quartz contain a large amount of CO2. Metamorphic fluids of middle to high temperatures and pressures and meteoric waters of low temperatures and pressures mixed together during mineralization. A proposed ore-forming model is as follows: in the pre-ore phase, the collision of SP and NCC resulted in the NS-trending compression of the ore belt. This formed the NE-trending and NW-trending shear faults and EW-trending folds. During the ore-forming phase, the collision of YC and NCC resulted in dextral shearing of the NW-trending Jiapigou fault and the NE-trending Green faults. High-pressure fluids caused by thecompressionflowedintothedilatantzone.ThismayhavecausedbothphaseseparationofCO2-bearingfluids and the mixing of meteoric waters, metamorphic waters and magmatic source fluids and finally resulted in the disequilibrium of the ore fluids and precipitation of ore minerals.
Databáze: OpenAIRE
Externí odkaz: