| Shihu gold deposit is a large-scale gold mine, a intense silicification- fault altered rock type deposit in the west of the Taihang mountain in Hebei and locates in the east of the Yanshan Mapeng granitic intrusion, the axial section of the middle-northern Fuping Mantle branch of Taihang Mountain's uplift. In the long history of geological evolution process,there were a series of multi-phase, multi-stage system of folds and faults in ore-forming district and this plays a very important controlling role in the formation and evolution of the gold mining area.Based on taking full advantage of predecessor's information and adopting the new perspective of mantle branch structure theory, this paper analyzes the mineralization of Shihu gold deposit by researching on the geological features of the deposit, the source of ore-forming minerals, ore-control structure, metallogenic regularities. the genesis of deposit and other aspects. All these features show that:1. By testing the ore sample,this thesis finds that the mineralization-age is 120.74±0.78Ma, yonger than the age of the Mapeng granitic intrusion, 135.1±8.8Ma.The ore-forming materials are from the deep section and the mineralization-solutions are mainly from the magmatic water and partly from the atmosphere water.2. The structure of the deposit district is very complicated and the ore veins are strictly constrained by the ore-control structures, but their significance are not the same. By the analysis of the tectonics evolution, this district has experienced four structural stages: the Fuping period, the Wutai and Lvliang period, the Yanshan period, the Himalaya period. Among all these periods, the Fuping period may be the initial enrichment, and the Yanshan period could be the main stage of mineralization.3.Mapeng granitic intrusion is a product of the partial melting of the upper mantle-material, originating between the lower crust and upper mantle. It has five pulsating units and the cause of the formation can be attributed to the same type of granite-type melting.And it is also closely related with the formation of deposit in time and space, and can partially provide some ore-forming materials.4.As the uplift of the regional metamorphic core complex rock and the frequent tectonic structural activity in the Mesozoic (Yanshan period), it form Fuping Mantle branch and a corresponding series of the NE sub-detachment zone and the NW cross-fault. With the main detachment zone' removing to a large extent and a certain temperature and pressure in the deep, the magma activated along the main detachment zone. This process opens the access for the deep mineral solution, provides storage space for ore and also forms nearly SN fault system by activating previous structure. The later ore-forming solutions playing the alteration role with wallrock along new fissures in the process of alteration , together with the part Au activated and transferred, which formed in early period form gold mine mineralization along the relevant structural weaknesses zone by injecting and gathering.5. Through statistical analysis of various level-bands' Au grade and width of the 101 ore-vein, which has been currently explored, this thesis finds that the 101 ore-vein turns wide and enriched towards the deep section. Coupled with a deep source of ore-forming minerals, 101 ore belt denuated very low and shearing the deep crust, and some information showing that: mineralization fluid's direction of the migration is from the southern deep to the northern shallow in the mining area, it can be concluded that there is a great potential in the deep prostecting.
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