| The Guanfang skarn scheelite deposit is located in the southwest side of the Banzhushan ore concentration area,and its tecton ic structure is located in the right River geosyncline fold zone of the South China quasi-platform,that is,the combination of the west coast Pacific Ocean and the Tethys tectonic domain.The large scale of mineralization,obvious contact with ore-controlling structure and clear surrounding rock alteration make it the most typical skarn type scheelite deposit on the southwest side of the thin Zhushan ore concentration area.Therefore,the study of geological-geochemical characteristics of this deposit is o f great significance to promote the prospecting work in this area.In this paper,the geological characteristics of ore deposits,the petrogeochemical characteristics of ore-forming granites and ore-bearing skarns are studied by means of detailed field geological survey and systematic rock and ore sampling tests.The vertical geochemical characteristics based on ZK107-3 have been systematically studied.The geological conditions of scheelite ore-forming in this area are shown by systematically summarizing and comparing the geotectonic position,strata ore-controlling property,structure-ore-controlling rule and ore-forming magmatic rocks in the area(Paozhushan ore-concentrated area),which shows that the scheelite ore-forming geological conditions in this area are superior.In the geological characteristics of the deposit,the concealed shape of the rock mass,the structure of the contact zone and the middle Cambrian strata are the important components of the scheelite formation in the area.The shape of orebody is divided into two categories and eight types.The distribution of layered orebody is continuous,the grade is uneven and low,while the convex lenticular orebody is scattered,but the ore body grade is rich.Scheelite is a kind of calc-tungsten ore in this area,which mainly exists in complex skarn,accompanied by galena,sphalerite and other metal minerals,such as galena,sphalerite and so on.The geological characteristics of ore-bearing skarn and ore-free skarn are significantly different: firstly,ore-bearing skarn is generally closer to the concealed granite body and has a darker color(dark green);Secondly,the ore-bearing skarn is mostly complex skarn,the mineral composition of which is mostly diopside + tremolite amphibole,while the volume fraction of garnet in ore-free skarn is the vast majority,and the other minerals are few.According to the geochemical characteristics of ZK109-2 ore-bearing skarn(45 points),the results show that garnet,hornblende and pyroxene belong to aluminite-ferrigarnet series,respectively,in Guofang mining area,the results show that garnet,hornblende and pyroxene belong to aluminite-ferrigarnet series,respectively.Diopside-calcium pyroxene series,tremolite-Yangqi series;The main quantity and trace test r esults of granites show that the ore-forming parent rocks in the area are continental crust remelted peraluminous monzonitic granites,and the Th/U,Zr/Hf,Nb/Ta,Rb/Sr of granites shows that the magma in the area has undergone highly evolutional differentiat ion.The main content of ore bearing skarn and trace test results show that the ore bearing skarn primordium is probably a high calcareous mudstone,and barium(Ba),strontium(Sr)is rich in lithophile elements,few depleted elements,and Rb/Sr,in ore bearing skarn.Zr/Hf and others reflect the shell-source characteristics of ore-forming materials.According to the typical section,the geochemical characteristics of the elements from carbonate rock,skarn to magmatic rock are generally a gradual process,which reflects the contact metasomatism of skarn scheelite.Based on the above-mentioned research,the ore-forming prediction basis is summarized,and the ore-forming prediction is carried out on the large area of the Putuo-Tong to the Guanfang,and the two target areas are successfully delineated: the target area of No.I: the office building,the large-waist store,the target area II: The rock and sheep slope is in the area of the cattail. |
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