The Study Of The Ore Characters And Metallogenic Phases Of The Au-Cu-Fe Deposit In Yinan Of Shandong Province

The Au-Cu-Fe deposit of Yinan is located on the west area of Shangdong province which lies in the west of Yishu fault zone, which lies in southeast of North China Plate. The deposit includes the Tongjing and Jinchang ore districts. The deposits formed in the inside and outside the intermediate-acidic complexes of the Yanshan period. It is controlled by magma, strata lithology, structure and so on. These layers can be found in the area. These are Yanlinguan unit of Archeozoic Taishan group, Tongjiazhuang unit of Proterozoic Tumen group, Changqing group of Cambrian Period, Jiulong group of later Cambrian Period, and layer of Quaternary Period. The magmatic rocks of the mine and the entourage of the mine are mainly quartz porphyritic diorite, monzonitic-porphyritic diorite, monzonitic granite and porphyritic granite.On the basis of previous work, we made further analysis on the ore characteristics and metallogenic phases of the Yinan gold deposit by the combination of microcosmic and macroscopical means.(1)There are mainly four ore deposits: magnetite, magnetite containing gold and copper, skarn containing gold and copper, marble containing gold and copper.(2)Besides the useful components of Au, Cu and Fe, the components of small quantity such as Co and S can also be recycled synthetically.(3)We find out preliminarily that the main metallic mineral are gold, chalcopyrite, pyrite, magnetite, bornite etc and the main nonmetallic mineral are grossular, epidote, quartz, chlorite and calcite and so on.(4)The main ore structure are massive structure, dissemination structure, vein structure, stockwork structure, banding structure and brecciated structure. The main ore textures are divided into two categories, crystallization structures and metasomatic texture. The crystallization structures can be further devided into automorphic granular structure, semi-automorphic granular structure, xenomorphic granular structure and containing structure, and the metasomatic texture can be divided into metasomatic residual texture, pseudomorph texture and margin metasomatic texture.(5)Based on the geological features, ore texture and structure, mineral associations, wall rock alteration and intersected and symbiotic relationships between the minerals, the mineralization of the deposit can be divided into three phases, skarn phase, quartz-sulfide phase and surface phase.