Stable Isotope Geochemistry Of Gansu Yangshan Gold Deposit

Noble gas isotopes and isotope tracer studies integrated into the stability of the minerals in the rock and mineral sources and constitute a source of great significance. Gansu Yangshan gold mine is one of the newly discovered large fine disseminated (Carlin-Carlin) type gold deposits. In this paper, the main gold-bearing minerals on the Yangshan gold pyrite sulfur, carbon, helium, argon isotopes studied, combined with previous data (hydrogen and oxygen), Plagioclase porphyry sulfur isotope distribution concentrated and close to zero,834S change at0.1‰～0.5‰, concentrated in the0.1‰～0.2‰, display deep sources; The sulfur isotope composition distribution phyllite wide range of3.768‰～9.496‰, the display section is also involved in the formation of sulfur mineralization; δ13C Yangshan gold deposit mineralization dam safety section is-32.53‰～9.867‰, Some carbon is also close to the source of organic carbon, More discrete, Show mineralization and sedimentary and igneous rocks have some genetic link. Sulfur, carbon isotope analysis showed that the Yangshan gold deposit as likely sources of minerals characteristic of mixed origin; Ore fluid inclusions in pyrite3He/4He between0.06-0.28Ra (average0.123Ra),40Ar/36Ar ratio of303.5-603.7(average448.3), Reflecting the ore-forming fluid mainly from atmospheric precipitation in the ore rock series deep cycle. Thus believe that the metallogenic fluid-based crust precipitation, while participating in a small part of the mantle fluid.Another gold-bearing quartz mineral ores in the study area of hydrogen and oxygen isotope values δD of-74‰～-86‰. Calculated on the basis of previous data show that818O水was10.25‰～15.24‰, On the mineralizing fluidδD-818O水diagram investment point of water falls magma-between metamorphic water and meteoric water line, and there is a trend towards the evolution of atmospheric precipitation. Composition and mineral pyrite helium and argon isotopes are basically the same, showing the main ore-forming fluids may meteoric infiltration of deep cycle through, and magmatic hydrothermal participation. Helium, argon and hydrogen and oxygen isotope analysis showed that the Yangshan gold deposit mineralization is mainly a mixture of magmatic fluids with meteoric water.