【作者】 陈波；

【导师】 薛春纪；

【作者基本信息】 长安大学 ， 矿产普查与勘探， 2011， 博士

【摘要】 新疆西天山莱历斯高尔—肯登高尔铜钼铅锌矿集区位于西天山博罗科努铜、金、钼、铅锌、铁、磷、硫铁矿成矿带的中西部,构造背景为博罗科努晚古生代活动陆缘的北坡。矿集区内成矿作用与晚古生代中酸性侵入岩有密切的空间和时间联系。相关的岩体主要有花岗闪长(斑)岩、二长花岗岩、钾长花岗岩。与碳酸盐岩接触部位形成矽卡岩型矿床,岩浆期后热液形成斑岩型及中低温热液脉型矿床。花岗闪长斑岩具有富集硅、铝、碱和富集Rb, Ba, Sr等大离子亲石元素,而亏损Ta、Hf, Zr、Sm、Th、Y、Yb等高场强元素。洋中脊花岗岩标准化的微量元素配分曲线与陆缘弧花岗岩配分型式相似。花岗闪长斑岩REE总量明显低于地壳重熔S型花岗岩的相应值,具有Ⅰ型或M型花岗岩浆的性质。锶同位素初始值为0.7079～0.7103,εNd(t)为-0.61～-3.71,指示岩浆具下地壳来源或壳幔混合源特点。矿集区内肯等高尔铜钼矿、来历斯高尔铜钼矿和七兴铅锌多金属矿三个典型矿床的矿石δ34SV-CDT平均值分别为1.14‰、3.8‰和4.0‰,前者显示硫源为幔源,后两者为壳幔混合源；铅同位素显示成矿物质来源具壳幔混合源特点；成矿流体属于低盐度、低密度流体,H、O同位素显示成矿热液为岩浆水并受到大气降水的混合。这三个典型矿床在成因类型、元素组合和成矿时代等方面存在明显差异,可划分出Cu-Mo、Fe-Cu、Pb-Zn、Au-Ag等多个成矿元素组合。其中,Cu-Mo的成矿作用产出在花岗闪长(斑)岩及与其相关的角岩、矽卡岩中,以莱历斯高尔-3571铜钼矿、肯登高尔铜钼矿为代表。Fe-Cu矿产于花岗岩与灰岩接触交代带部位的内(外)矽卡岩中,以哈勒尕提矿床为代表。Pb-Zn、Au-Ag的成矿作用与岩浆期后热液和构造有关,以七兴铅锌矿为代表。矿集区内元素分布与花岗岩和构造相关,花岗岩与陆源碎屑岩(如上志留统博罗霍洛山组细碎屑岩)接触部位产生热接触变质作用,形成角岩和铜钼矿；而与碳酸盐岩接触部位形成矽卡岩,并伴随铜钼和铁铜的成矿作用；远离岩体,则受构造控制在岩石裂隙中形成中低温热液脉型铅锌矿和金银矿。各成矿元素组合的形成时代规律明显：Cu-Mo矿形成于早石炭世,Fe-Cu矿形成于晚泥盆世—早石炭世,Pb-Zn矿形成于晚三叠世—早侏罗世,而Au-Ag矿形成时代由于没有相关测年数据,推测为石炭纪或燕山期。从晚泥盆世—石炭纪—晚三叠世—早侏罗世,成矿元素组合依次为Fe-Cu, Fe-Cu-Mo-(Au-Ag?), Pb-Zn-(Au-Ag?)。莱历斯高尔—肯登高尔一带多金属矿集区成矿作用与区内构造岩浆作用是同一地质—构造—岩浆活动过程在不同阶段的产物,是区域内同一成岩成矿系统综合作用的结果。更多还原

【Abstract】 Lailisigaoer-Kendenggaoer Copper-Molybdenum-Lead-Zinc ore cluster lies at the Midwest of Boluokenu copper, gold, molybdenum, lead, zinc, iron, phosphorus, pyrite ore belt in West Tianshan, Xinjiang. The tectonic setting of the ore cluster is the north slope of Late Paleozoic Boluokenu active continental margin. Ore mineralization is closely related to acid intrusive rocks in the region in the late Paleozoic in space and time. Mainly related rocks are granodiorite/granodiorite porphyry, monzogranite and moyite. Skarn deposit forms in contact section between acid intrusive rock and carbonate rock, while porphyry-type deposits and mid-low temperature heat vein type deposits related to postmagmatic hydrothermal. Granodiorite porphyry is enriched in silicon, aluminum, alkali and large ion lithophile elements such as Rb, Ba and Sr, but depleted in high field strength elements such as Ta, Hf, Zr, Sm, Th, Y and Yb. Ocean ridge granite normalized trace element distribution patterns are similar with continental margin arc distribution patterns. The Rare Earth Elements content of Granodiorite porphyry was significantly lower than that of S-type granites and has the nature of I-type or M-type granitic magma.The initial strontium value is 0.7079-0.7103 and theεNd(t) value is-0.61 to-3.71 indicating that magma derived from the lower crustal source or crust-mantle mixing source.The average oreδ34Sv-CDT value of Kendenggaoe copper-molybdenum ore, Lailisigaoer copper-molybdenum ore and Qixing copper zinc polymetallic ore deposits in this ore district is 1.14‰,3.8‰and 4.0‰respectively, the former shows sulfur source for the mantle and the latter two for the crust-mantle mixing source; lead isotopes show that the source have a mixture of crust and mantle characteristics; forming fluids are low salinity and low-density fluid. Hydrogen and oxygen isotopes show hot forming magmatic fluids by meteoric water and mixing. The three typical deposits are significantly different in genesis, element association and mineralization times, and these elements association can be divided into the Cu-Mo, Fe-Cu, Pb-Zn, Au-Ag ore-forming elements and other combinations. In which, Cu-Mo mineralization outputs in granodiorite/ granodiorite porphyry and associated hornfels and skarn, with Lailisigaoer-3571 copper-molybdenum mine and Kendonggaoer copper-molybdenum mine represented. Fe-Cu deposit output in the inner (outer) skarn of granite and limestone contact metasomatic zone parts, with Halegati deposit represented. Pb-Zn and Au-Ag mineralizations as the representative of Qixing lead and zinc deposit are related to postmagmatic hydrothermal and structural. Distributions of elements in the ore region are associated with granite and structural.Contact parts between granite and terrigenous clastic rocks (as Boluohuoluoshan formation clastic rocks of upper Silurian) had thermal contact metamorphism and formed hornfels and copper-molybdenum deposit; while in the contact area between granite and carbonate formed skarn and copper-molybdenum and copper-iron mineralization. Away from the rock, mid-low hydrothermal vein type lead-zinc and gold-silver mine controlled by structures in the rock fractures, the ore formation age elements associations have obvious rule:Cu-Mo ore formed in the Early Carboniferous, Fe-Cu ore formed in the Late Devonian-Early Carboniferous, Pb-Zn ore formation in the Late Triassic-Early Jurassic, and Au-Ag ore may form in Carboniferous or Mesozoic because of lacking relevant dating data. From Late Devonian-Carboniferous-Late Triassic-Early Jurassic, forming elements were combined Fe-Cu, Fe-Cu-Mo-(Au-Ag?) and Pb-Zn-(Au-Ag?). The mineralization of Lailisigaoer-Kendenggaoer polymetallic ore cluster area and regional tectonic magmatism were the product of the same geological-tectonic-magmatic processes at different stages and the results of the combined effects in the same region diagenetic-mineralization system.更多还原