现代地质2025，Vol.39Issue(3)：598-611,14.DOI:10.19657/j.geoscience.1000-8527.2025.032
黑龙江争光金矿床角闪辉长岩锆石U-Pb定年、Hf同位素组成及找矿意义
Zircon U-Pb Dating,Hf Isotope Composition and Prospecting Significance of Diorite Porphyry in the Zhengguang Gold Deposit,Heilongjiang Province
摘要
Abstract
Mafic-ultramafic dykes often have a close genetic relation with Au deposit.Properly understanding this relationship can provide a centain degree of guidance for mineral-prospecting.The concealed hornblende gabbro of Zhengguang is located within the Zhengguang gold mining area,situated on the eastern slope of the Greater Khingan Mountains in the Duobaoshan ore concentration district.Through conducting zircon U-Pb dat-ing and Hf isotope composition analysis,the age of the hornblende gabbro zircon was determined to be(117.3±2.4)Ma.Additionally,two groups of captured magmatic zircon ages were identified,ranging from(468-484)Ma and(489-550)Ma,indicating that the dike was formed during the Early Cretaceous period.The zircon Hf isotopes exhibit εHf(t)values ranging from-2.33 to 12.78.The sample data points fall within the range of the Early Cretaceous volcanic rock belt of the Greater Khingan Mountains.The Hf isotope values show significant variation,predominantly positive,which is associated with contamination from mantle-derived magma mixed with crustal materials.The fLu/Hf ratios range from-0.96 to-0.90,and the two-stage model ages are concentrated between 533 and 1316 Ma.The light and heavy rare earth elements show significant fractionation,with the curve leaning to the right.There is depletion in Nb,Sr,and Zr,while Th,Ta,and Nd are enriched.The contents of Zr(26.6 × 10-6-35.8 × 10-6),Hf(1.39 × 10-6-2.08 × 10-6),and Cr(102 × 10-6-360 × 10-6)vary,and the ratios of La/Nb(142.5-214.8)and Zr/Ba(0.16-0.19)reflect characteristics of mantle-derived magma,indicating formation in an extensional tectonic setting.The hornblende gabbro and the gold mineralization in the Nenjiang-Heihe metallogenic belt,such as that in the Sandaowanzi area,as well as the dioritic dikes associated with mineralization,were formed during the same period(110-125 Ma)and under similar extensional tectonic settings.This suggests that these dikes may serve as indicators for the Early Cretaceous gold mineralization in the Zhengguang mining area.关键词
角闪辉长岩/锆石U-Pb定年/Hf同位素/金矿床/大兴安岭/黑龙江Key words
diorite porphyry/zircon U-Pb dating/Hf isotope/gold deposit/Greater Khingan Mountains/Hei-longjiang Province分类
天文与地球科学引用本文复制引用
刘宝山,寇林林,李成禄,王泽宇,罗建,张春鹏,杨元江,韩仁萍..黑龙江争光金矿床角闪辉长岩锆石U-Pb定年、Hf同位素组成及找矿意义[J].现代地质,2025,39(3):598-611,14.基金项目
中国地质调查局项目"大兴安岭成矿带战略性矿产调查"(DD20240061),"东北地区铜金稀有金属战略性矿产地质调查"(DD20230028). （DD20240061）
