| The Ketinghaer copper polymetallic deposit in the Geermu city of Qinghai Province is located in the eastern part of the Qimantage metallogenic belt in the east Kunlun.It is a new discovered by the Third Geology and Mineral Exploration Institute in Qinghai Province.The author has the honor to participate in the exploration and evaluation work of the mining area.Depending on the exploration project,the paper studies,starting from the metallogenic geological background,summarizes the geological characteristics and conditions of the deposit,analyses the genesis and metallogenic regularity of the deposit,establishes prospecting criteria,and evaluates the further prospecting potential.The main strata exposed in the study area are the Paleoproterozoic Jinshuikou rock group,which is divided into gneiss group,marble group,and amphibolites group.The Jinshuikou rock group is the advantages stratum for the formation of the skarn.The tectonic activities in this area were intense,and the NWW-NW trending compression and compresso-shear faults are formed as the tectonic framework of this area,with the characteristic of multi-stages and multi-group in this area,which provide favorable channels for ore-forming.Variscan diorite and Indosinian intermediate-acid granitoids are well developed,Indosinian granodiorite serves as the main ore-bearing rock-body in the mining area.Three ore belts have been delineated in the area,of which porphyry copper-molybdenum ore is the main ore belt,accompanied by hydrothermal vein type lead-zinc ore,and skarn type iron-polymetallic ore is the second and third ore belts.Developments of areal silicification and potassic alteration zone in cataclastic rocks and fractured granodiorites in No.1 ore belt.Seven copper orebodies,seven zinc orebodies,two lead-zinc orebodies,two molybdenum orebodies and one copper-molybdenum polymetallic orebody have been circled out.Diopside skarnization,silicification,epidotetization and chloritization are developed along the inner contact zone between granodiorite and marble along the north-south direction in No.2 ore belt,and one skarn-type lead-zinc ore body has been found.Copper,zinc and magnetite mineralization is found in the skarn and breccia belts of the No.3 belt.It is believed that the marble of the Paleoproterozoic Jinshuikou Group,the NE-trending and nearly N-S-trending fault structures and the Indosinian granodiorite played an important role in controlling the formation of iron and copper polymetallic deposits in the area and constituted the metallogenic geological conditions.Silicification,potassium,sericitolitation,carbonation,and skarnization related to skarn and hydrothermal processes and regional 1:50,000 geochemical anomalies and 1:10,000 soil element anomalies are the main indicators of iron and copper polymetallic prospecting.Based on the ore-control factors and prospecting criteria,it is determined that the study area has good prospecting potential.The outer contact zone and bottom of breccia pipe structure are explored to find the central part of mineralization,and to strive for greater breakthroughs in prospecting.The NE-trending tectonic belt in the ore-bearing granodiorite porphyry body in the western region corresponds to the low negative anomaly,which can clearly reflect the structural distribution.A large number of low magnetic anomaly areas are favorable areas for forming polymetallic deposits.Finally,based on the geophysical and geochemical anomalies,it is determined that the Ketinghaer mining area has further prospecting potential. |
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