Research On The Genetic Mineralogy And Genesis Model Of Jinchiling Gold Deposit In Zhaoyuan County,Shandong

Jinchiling gold deposit is a medium-sized quartz vein type gold deposit locatedin the Zhaolai metallogenic belt northwest of Jiaodong area．It is controlled by theintensive subprime NE-NNE-trending structural fissure which is developed in thefootwall of Zhaoping fault zone．Its surrounding rock is the Linglong granite andGuojialing granodiorite．In this paper, we do main research on the deposit geology,mineralization, rock and ore geochemistry and fluid inclusions of Yuantuan miningdistrict in Jinchiling gold deposit.In this distric, The ore types are mainly quartz-pyrite ores and polymetallicsulfide ores, composed of metal sulfide minerals, quartz and carbonate minerals. Thetextures of ores are predominant by euhedral medium-coarse grained texture,cataclastic subhedral medium-coarse grained texture and xenomorphic fine grainedtexture, sometimes also turn up interstitic texture, poikilitic texture, graphic textureetc. The structures of ores are predominant by massive structure, dense disseminatedstructure and vein structure. The gold minerals mainly are electrum and kustelite inthe form of intergranular gold, issure gold and enclosed gold. The mineralizationstages contain pyrite-quartz, quartz-pyrite, polymetallic sulfides and quartz-carbonatestages. The types of wall rock alteration include potassic feldspathization,sericitization, silicification, pyritization and carbonatization, etc. Potassicfeldspathization and sericitization are the activation and migration process of gold andits associated ore-forming elements. Silicification and pyritization are theprecipitation and enrichment process of gold and its associated ore-forming elements.Through the alteration, ore-forming elements complete the enrichment process bycycles of activation�'migration�'enrichment and finally form a gold deposit.In the early and late mineralization, the morphological characteristic of pyrite ismainly cube. In the main mineralization, pyrite crystal is complex. Morphologicalcharacteristic is mainly combination of pentagonal dodecahedron and cube. Thethermoelectric conduction type of pyrite is mainly mixture of type P and type N.Good ore forming prospects are presumed in the deep part of Yuantuan distric, on basis of the accordance of gold grade and the occurrence of type P. The analysis ofquartz fluid inclusion shows that Jinchiling gold deposit is a hydrothermal golddeposit formed in mid-shallow，mid-low temperature，low salinity condition.The analysis of stable isotopes(C-H-O、He-Ar、S-Pb) of the ore minerals suggeststhat the ore-forming fluid is mainly crustal fluid and precipitation mixed with a littlemantle origin fluid. The metallogenic materials are originated from the lower crustand a little mantle. It also have some materials of surrounding rock. The depositgenesis model is speculated that the magma-fluids originated from the lower crustwith a little mantle materials differentiated and evolved continuously. It formeddifferent magmatic rock and ore-forming fluids. The ore-forming fluids rose throughthe NE-NNE-trending faults with mixture of the atmospheric precipitation andsurrounding rock. In the end, the gold deposit was formed in specific positions.