Evolution of ore-forming fluids in the Sawayaerdun gold deposit in the Southwestern Chinese Tianshan metallogenic belt, Northwest China

Geology, fluid inclusion geochemistry, and 40Ar/39Ar geochronology of the Wulasigou Cu deposit, and their implications for ore genesis, Altay, Xinjiang, China

“…The salinities of FIs evolved from 0.9-6.5 wt.% NaCl equiv early, through to bimodal 2.7-11.2 and 34.7-38.1 wt.% NaCl equiv middle, and to 0.9-2.9 wt.% NaCl equiv late, strongly suggesting that fluid boiling and volatile escape occurred in the middle stage. Fluid immiscibility in middle stage resulted in crystallization of daughter mineral-bearing FIs that have been reported in studies of the orogenic lode deposits, such as the Wiluna gold deposit in western Australia (Hagemann and Luders, 2003); Sawayardun gold deposit in the southern Tianshan, China (Chen et al, 2012a); Zhifang Mo-bearing deposit in Qinling, China (Deng et al, 2008); Lengshuibeigou Pb-Zn deposit in Qinling, China (Qi et al, 2007); and the Tiemurt Pb-Zn-Cu deposit adjacent to the Wulasigou deposit. Fluid immiscibility during middle stage copper deposition is strongly supported by both the coexistence of different types of FIs with similar homogenization temperatures in a single FI assemblage cluster (as exemplified in Fig.…”

“…According to the metallogenic models applied elsewhere for both accretionary orogeny (Goldfarb et al, 1991 and collisional orogeny (Chen and Fu, 1992;Chen et al, 2005), the CAOB is prospective for orogenic deposits formed during the processes of oceanic plate subduction, terrane accretion, and continent-continent collision. However, in western CAOB, orogenic deposits have not yet been reported, except for orogenic gold deposits (Chen et al, 2000(Chen et al, , 2001(Chen et al, , 2012aGoldfarb et al, 2003). Therefore, the study of representative orogenic deposits in the CAOB is of significant interest.…”

Geology and fluid evolution of the Wangfeng orogenic-type gold deposit, Western Tian Shan, China

“…With continuous crustal uplift and erosion, the deeplyburied early quartz veins and structural zones were uplifted resulting in decompression. This change in tectonic conditions led to the fluids trapped in structural zones to experience extensive fluid immiscibility due to decreasing pressure (Cox et al, 1995;Chen et al, 2012b) and precipitated quartz and also Au and pyrite at medium temperatures (210-340°C; Fig. 9B).…”

Micro-textural and fluid inclusion data constraints on metallic remobilization of the Ashele VMS Cu-Zn deposit, Altay, NW China

“…1) (Chen, 2000;Xiao et al, 2008). The Chinese Altay Orogenic Belt has experienced an episodic geotectonic evolution, including consecutive episodes of accretion, subduction, (Chen et al, 2012a(Chen et al, , 2012b(Chen et al, , 2012c opening and closure of small basins and final orogenesis (Goldfarb et al, 2003). The area comprises of four major tectonic units from north to south (Fig.…”

“…The Chinese Altay Orogen forms the main part of the Central Asian Orogenic Belt (CAOB) which is considered as an accretionary orogen with episodic oceanic plate subduction and continental growth from the Neoproterozoic to the Permian, and continent-continent collision which occurred during the Late Carboniferous to Early Triassic (Sengor and Natal'in, 1996;Chen, 2000;Xiao et al, 2003Xiao et al, , 2008Xiao et al, , 2009Chen et al, 2012aChen et al, , 2012bChen et al, , 2012c. The geodynamic evolution of the Altay Orogenic Belt resulted in the formation of numerous sizeable ore deposits with substantial reserves, including abundant VMS deposits (Yang et al, 2013;Lobanov et al, 2014).…”