Geochemical Characteristics and Source of Ore-Forming Materials of Kaerqueka Copper Polymetallic Deposit in Qinghai Province,China
Lai Jianqing
Huang Min
Song Wenbin
Su Shengshun
Wang Shouliang
Abstract：Combined with field investigation and ore-forming geological conditions of the Kaerqueka copper polymetallic deposit, the geochemical characteristics of the deposit are summarized,the origin of the ore-forming materials is ascertained,and the rock-forming and ore-forming mechanisms are discussed according to the S,Pb isotopes as well as chemical analysis,including major element analysis,trace element analysis.Results of typical magmatic rocks,wall rocks and ores show that the magmatic rocks which were derived from deep and affected by crustal contamination during intrusion are intermediate acidity comagmatic rocks and belong to the high-K calc-alkaline series.All REE distribution patterns of different geologic bodies incline to the right and LREE-rich,indicating that the magmatic rock,skarn and ore belong to the same metallogenic system.The geochemistry of trace elements shows that the granites of the deposit occurred in volcanic arc environment.Theδ34 SCDT values of ore minerals lie between those of magmatic rock and country rock sulfur,with a range of 4.4‰ to 1 1.0‰,which indicates various metallogenic material sources.The Th/U values of lead isotope in ore minerals range from 3.46 to 3.69 and theμ values range from 9.46 to 9.52 (<9.58),which fall between the values of crust and primitive mantle and indicate that the ore lead is characterized by both deep-sourced and crust-sourced origins.The tracer analysis regarding the characteristic parameters,lead composition mod-el and Δβ-Δγ diagram show that the ore lead is mainly crust-derived and mixed with minor mantle-derived lead and affected by magmatism.The geochemical characteristics of Kaerqueka deposit suggest that the ore-forming materials mainly originated from magma with minor strata substance.The complicated evolution of magmatic rock is revealed by the porphyry-type copper-molybdenum mineralization in magmatic rock,the skarn-type lead-zinc mineralization following the contact of carbonate rock and the late low-medium hydrothermal vein-type gold mineralization,which indicates the Kaerqueka deposit is a polygenetic compound deposit.
Keywords：geochemistryisotopeore-forming material sourceKaerquekaQinghai Province
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：16( 1-16 )