Geochemical characteristics and metallogenesis of Carlin-type gold deposits in the Sandu-Danzhai metallogenic zone, Guizhou Province, China
文摘
Geochemical studies of the Paiting and Miaolong Carlin-type gold deposits in the Sandu-Danzhai metallogenic zone, Guizhou Province, have shown that the mineralized-altered rocks show LREE-enrichment patterns, generally displaying negative Eu anomalies (δEu=0.51-.97) and unobvious negative Ce anomalies (δCe=0.86-.99). Calcite and fluorite in relation with metallogenesis show MREE-enrichment patterns, generally displaying rather weak negative Eu anomalies (δEu=0.74-.93) and weak negative Ce (δCe=0.70-.98) anomalies. The δ13CPDB values of carbon in calcite are ?.61‰–?5.82- the δ18OSMOW values of oxygen are 13.97‰-9.24- and the δ34SCDT values of sulfur in stibnite are 17.72‰-1.68- In regard to δD and δ18O, ore-forming fluids possess the characteristics of metamorphic water. The process of metallogenesis of the Carlin-type gold deposits is controlled by the Yanshanian tectonic activities. The Yanshanian movement promoted the migration and mobilization of metamorphic fluids in the extensively developed medium-to high-grade metamorphic rocks in this region, carrying primarily enriched gold and associated elements such as Hg, As, and Sb in the Sinian metamorphosed black shales and Lower Cambrian black shales. The ore-forming fluids found their way into a suitable metallogenic environment along the fault zone, followed by gold precipitation to form gold deposits.