| The Womagou copper polymetallic ore deposit in Qinghai Province is located at the intersection of the East Kunlun orogenic belt and the West Qinling orogenic belt.The geotectonic location belongs to the western region plate,ZongWuLong Mountain-Qinghai South Mountain late Paleozoic-early Mesozoic taphrogenic trough,ZongWuLong Mountain-Xinghai Aulacogen.The Proterozoicjinshuikou group,carboniferous-middle Permianturgenite plate formation,the middle lower Triassic longwuhe formation and the quaternary strata are the main strata in this area.The magmatic activity is relatively intense.There is outcrop from intrusive rock to extrusive rock.The intrusive rocks are exposed to varying degrees from Proterozoic to indosinian.Especially,the indosinian intrusive rocks,mainly intermediate-acid rocks are more intense.At the same time,affected by multiple tectonic movements in Lvliang period,Hualixi period and indosinian period,the fold deformation of is strong.The indosinian tectonic movement causes the fold deformation of the indosinian layer and a series of folds and faults formed by the tectonic movement in the indosinian period play an important role in the formation of minerals in the area.According to the previous results of 1?200000 geochemical explorations and 1?50000 sediment measurements in Womagou area,the anomalies are separated and analyzed,and AS-2 anomaly is selected as the main working area.A 1?10000 soil geochemical survey is carried out in the 1?50000 water system anomaly AS-2 anomaly,and a total of 5 comprehensive anomalies are circled.Through the study of the original data and background data,it is considered that Au,Sb,As and Cu are the main metallogenic elements in the exploration area.Based on the analysis of geological IV background,it is considered that the middle and lower Triassic Longwuhe formation is the main ore-bearing strata in the exploration area.According to the characteristics of 1?10000 soil anomaly,1?10000 high-precision magnetic survey,IP anomaly and structure,a total of 6 mineralized alteration zones are delineated in the census area,including 3 copper mineralized zones and 3 copper and gold mineralized zoned.The ore bodies are mostly lenticular and layered.The occurrence status of elements was analyzed using the field and microscopic features of rocks and ores.The ore types are disseminated,fragmented and scattered.According to the study and analysis,explore the genesis of the deposits through studies of rock geochemistry,and fluid inclusions,The ore-forming process includes three stages.The fluid inclusions are composed of gas and liquid facies,the metallogenic pressure is about 13.54-32.03 MPa,the mineralization depth(the major metallogenic stage)is about 2.12-2.4 km,the ore-forming fluid of the major metallogenic stage is of the middle-low temperature,low salinity and low density.The main metallogenic types in the area are hydrothermal filling type and tectonic altered rock type,and the metallogenic period is late indosinian epoch.The wall rock alteration related to mineralization includes carbonation,silicification,pelification,kaolinization,sericitization and limonization.The metallogenic type is hydrothermal filling type and tectonic rock type.In this paper,the strata conditions,tectonic conditions and magmatite conditions in the mining area are summarized.Combined with the geophysical and geochemical characteristics,the prospecting indicators in the mining area are extracted.(1)In the geochemical characteristics of soil,the abnormal concentration centers of Cu,Au and As elements with large abnormal areas and high contents are important prospecting areas.Pb-Zn-Cu anomaly combination can be used as a direct indicator of ore-prospecting.Au and As can be used as indirect prospecting indicators.(2)The locations of the local positive and weak magnetic anomalies on the negative magnetic anomaly background in the IP profile with low resistance and high polarization and 1?10000 high precision magnetic surveys are consistent with the mineralized alteration and fracture zone,which are important geophysical markers.(3)Near east-west faults,there are often large scale alteration zones,which are important prospecting criteria for copper polymetallic ores.(4)Forming oxide bands on the surface,oxidized minerals are important outcrops of polymetallic minerals in this area.According to the geological characteristics,geochemical characteristics and geophysical characteristics of the area,it is considered that there are better metallogenic conditions in this area.Three ore-prospecting target areas are selected by synthesizing all kinds of various ore-prospecting indicators to provide the basis for the follow-up work. |
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