中国地质2024，Vol.51Issue(2)：371-384,14.DOI:10.12029/gc20200829001
东昆仑造山带岩浆镍钴硫化物矿床形成构造背景探讨
Tectonic settings discussion of magmatic nickel-cobalt sulfide deposits in the eastern Kunlun orogenic belt
摘要
Abstract
This paper is the result of mineral exploration engineering. [Objective]The Xiarihamu giant magmatic nickel-cobalt sulfide ore deposit in the eastern Kunlun orogenic belt,the largest magmatic nickel-cobalt sulfide deposit discovered in orogenic belt in the world,is the world's largest prospecting breakthrough in the magmatic sulfide deposits area in the past twenty years after the discovery of the Voisey's Bay deposit in Canada.In addition,several large-scale magmatic nickel-cobalt sulfide deposits,such as Shitoukengde,were discovered,indicating enormous prospecting potential in the eastern Kunlun orogenic belt.[Methods]Accurate zircon U-Pb dating found that the ore-bearing mafic-ultramafic rocks in the eastern Kunlun orogenic belt formed at 425-330 Ma.The ore-bearing mafic-ultramafic rocks are distributed along the north Kunlun fault and the central Kunlun fault.The ore-bearing mafic-ultramafic rocks reflected a large-scale magmatism event.[Results]The lithofacies of these ore-forming rocks are mainly dunite,pyroxene peridotite,and pyroxenite.The SiO2,MgO,Al2O3,and CaO content ranges from 31.52%to 53.31%,from 7.5%to 39.03%,from 0.1%to 16.01%,and from 0.23%to 13.85%,respectively.On the Harker diagram,the MgO content is negatively correlated with SiO2,Al2O3,Na2O,and K2O,respectively.The total amount of rare earth elements is between 6.36×10-6 and 81.5×10-6,with an average of 29.92×10-6.The average LREE/HREE,(La/Sm)N,(La/Yb)N,(Sm/Nd)N,(Gd/Yb)N value is 5.34,2.58,5.99,0.76,and 1.78,respectively,indicating the degree of differentiation between light and heavy rare earths is high.On the primitive mantle-normalized trace element spider diagram,the ore-bearing mafic and ultramafic rocks have a relatively uniform distribution curve,which are characterized by depletion of high field strength element(Ta,Nb,Ti,and P)and enrichment of large-ion lithophile elements(Rb,Th,and U).The Sr and Nd isotope data indicate that the magma source areas of the Xiarihamu ultramafic intrusion and the Shitongkengde ultramafic intrusions were derived from the asthenosphere mantle.The δ34S value shows a high positive value,revealing that crustal-sulfur contamination played a great role during sulfide saturation.[Conclusions]Based on the regional tectonic evolution,we believed that the magmatic nickel-cobalt sulfide deposits in the eastern Kunlun orogenic belt are associated with the break-up of the Paleo-Tethys Ocean.This opinion is significant to the ore-forming theory of magmatic nickel-cobalt sulfide deposits in the orogenic belt and could guide the regional exploration of the magmatic nickel-cobalt sulfide deposits.关键词
镁铁—超镁铁质岩/构造背景/岩浆成矿作用/镍钴矿床/东昆仑造山带/矿产勘查工程Key words
mafic-ultramafic intrusions/tectonic settings/Paleox Tethys Ocean/magmatic nickel-cobalt sulfide deposit/eastern Kunlun orogenic belt/mineral exploration engineering分类
天文与地球科学引用本文复制引用
张照伟,钱兵,王亚磊,李文渊..东昆仑造山带岩浆镍钴硫化物矿床形成构造背景探讨[J].中国地质,2024,51(2):371-384,14.基金项目
国家自然科学基金地质联合基金项目"昆仑成矿带及西延镍钴锂矿产境内外对比与跨境成矿规律研究"(U2244204)、第二次青藏高原综合科学考察研究"稀贵金属(金、镍、钴、铬铁矿、铂族元素)科学考察与远景评估"(2019QZKK0801)及中国地质调查局项目(DD20240128)联合资助. Supported by the projects of the National Natural Science Foundation of China"Comparative study of across national border metallogeny of Ni-Co-Li deposits in the Kunlun orogenic belt and its western extension"(No.U2244204),the Second Comprehensive Scientific Investigation and Research Project of the Qinghai-Tibet Plateau(No.2019QZKK0801),and China Geological Survey(No.DD20240128). （U2244204）
