Zircon U-Pb Dating,Petrogenesis and Tectonic Significance of the Granodiorite in the Sankuanggou Skarn Fe-Cu Deposit, Heilongjiang Province
详细信息
- 责任者：Chu Shaoxiong (Key Laboratory of Mineral Resources ; Institute of Geology and Geophysics ; CAS ; Beijing 100029 ; China) ; Liu Jianming
- 刊名：Acta Petrologica Sinica
- 出版年：2012
- 卷期：28(2)
- 关键词：铁矿 ; iron ores ; 铜矿 ; copper ores ; 花岗闪长岩 ; granodiorites ; 黑龙江省 ; Heilongjiang Province
- 页码：p.433-450
- 图表：12 illus., 4 tables, 68 refs.
- 分类号：1001
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
The Sankuanggou Fe-Cu deposit,located in northern Heilongjiang Province,is a typical skarn deposit which occurs in the NW trending Luohe-Duobaoshan-Sankuanggou metallogenic belt of northern part of the Da Hinggan Range.The ore-related Sankuanggou granodiorite yields a concordia LA-ICP-MS zircon U-Pb age of 175.9±1.6Ma in good consistently with 238U/206Pb weighted average age within error.This age indicates that there was an important Jurassic magmatic-hydrothermal Fe-Cu mineralization event in the Duobaoshan metallogenic district.The Sankuanggou granodiorite has a geochemical affinity of arc magmas:Na-rich(Na2O/K2O=1.39～1.59) ,metaluminous(ACNK=0.87～0.91) ,enrichment in LREE((La/Yb) N=8.02～10.45) and LILEs(U,Th and Pb) with minor negative Eu anomalies(δEu=0.82～0.98) ,depletion in HFSE(Nb,Ta,Zr,Hf and Ti) .Sr-Nd-Pb isotope systematics display that the Sankuanggou granodiorite also has a low initial Isr((87Sr/86Sr) i=0.7041～0.7045) ,high initial 143Nd/144Nd value((143Nd/144Nd) i=0.512556～0.512576) ,positive εNd(t) (2.8～3.9) ,young depleted-mantle model ages(tDM2=647～733Ma) and mantle-derived Pb isotopic characteristics.These geochemical characteristics indicate that the magma source of the Sankuanggou granodiorite may be mainly derived from deleted mantle source.The geochronology,geochemistry and isotope characteristics of the Sankuanggou granodiorite,combined with tectonic evolution of northeastern China,suggest that this deposit was formed in the magmatic arc setting,implying that its formation is probably related to the subduction of the paleo-Pacific Ocean during the Jurassic Period.