摘要
The Xiaokele Cu(–Mo)deposit is a recently discovered porphyry deposit in the northern Great Xing’an Range(GXR)of northeast China.The ore bodies in this deposit are mainly hosted within granodiorite porphyry intrusions.Potassic,phyllic,and propylitic alteration zones develop from center to edge.In this paper,we present zircon LA–ICP–MS U–Pb ages,zircon Hf isotopic compositions,and whole-rock geochemistry of the ore-bearing granodiorite porphyries from the Xiaokele Cu(–Mo)deposit.Zircon U–Pb dating suggests that the Xiaokele granodiorite porphyries were emplaced at 148.8±1.1 Ma(weighted-mean age;n=14).The Xiaokele granodiorite porphyries display high SiO2,Al2O3,Sr,and Sr/Y,low K2O/Na2O,MgO,Yb,and Y,belonging to high-SiO2 adakites produced by partial melting of the subducted oceanic slab.Marine sediments were involved in the magma source of the Xiaokele granodiorite porphyries,as indicated by enriched Sr–Nd isotopic compositions(eNd(-t)=-1.17–-0.27),low positive zircon eHf(t)values(0.4–2.2),and high Th contents(4.06–5.20).The adakitic magma subsequently interacted with the mantle peridotites during ascent through the mantle wedge.The Xiaokele granodiorite porphyries were derived from slab melting during the southward subduction of the Mongol–Okhotsk Ocean.
基金
the National Natural Science Foundation of China(No.41272093)
National Key R&D Program of China(No.2017YFC0601304)
Natural Science Foundation of Jilin Province(No.20180101089JC)
Key Projects of Science and Technology Development Plan of Jilin Province(No.20100445)
Self-determined Foundation of Key Laboratory of Mineral Resources Evaluation in Northeast Asia,Ministry of Natural Resources(No.DBY-ZZ-19-04)
Heilongjiang Research Project of Land and Resources(No.201605 and 201704)。
