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现代地质 ›› 2024, Vol. 38 ›› Issue (01): 128-153.DOI: 10.19657/j.geoscience.1000-8527.2023.082

• 矿物学、岩石学、矿床学 • 上一篇    下一篇

锡霍特—阿林造山带那丹哈达地体四平山金矿床成因与构造背景:锆石U-Pb年代学、岩石和流体地球化学制约

何云龙1(), 张国宾1,2(), 杨言辰3, 冯玥1, 孔金贵1, 陈兴凯4   

  1. 1.辽宁工程技术大学矿业学院,辽宁 阜新 123000
    2.山西工程技术学院地球科学与工程系,山西 阳泉 045000
    3.吉林大学地球科学学院,吉林 长春 130061
    4.江苏煤炭地质物测队,江苏 南京 210000
  • 收稿日期:2023-05-08 修回日期:2023-08-15 出版日期:2024-02-10 发布日期:2024-03-20
  • 通讯作者: 张国宾,男,副教授,硕士生导师,1983年出生,矿产普查与勘探专业,主要从事矿床学与矿产勘查方向的科研与教学。Email:zhangguobin85@163.com
  • 作者简介:何云龙,男,硕士研究生,1999年出生,矿产普查与勘探专业,主要从事岩石学、矿床学方面的研究。Email:hyl991206@163.com
  • 基金资助:
    中国地质调查局项目(1212011120342);辽宁省科技厅面上基金项目(20170540428);辽宁省科技厅面上基金项目(201601370);辽宁省教育厅面上基金项目(LJ2019JL027)

Genesis and Tectonics of the Sipingshan Gold Deposit in Nadanhada Terrane, Sikhote-Alin Orogen: Constraints from Zircon U-Pb Chronology, Petrological and Fluid Geochemistry

HE Yunlong1(), ZHANG Guobin1,2(), YANG Yanchen3, FENG Yue1, KONG Jingui1, CHEN Xingkai4   

  1. 1. School of Mines, Liaoning Technical University, Fuxin, Liaoning 123000, China
    2. Department of Earth Science and Engineering, Shanxi Institute of Technology, Yangquan, Shanxi 045000, China
    3. College of Earth Sciences, Jilin University, Changchun, Jilin 130061, China
    4. Jiangsu Coal Geophysical Prospecting and Surveying Team, Nanjing, Jiangsu 210000, China
  • Received:2023-05-08 Revised:2023-08-15 Online:2024-02-10 Published:2024-03-20

摘要:

黑龙江省虎林市四平山金矿床位于那丹哈达地体东部,为该地体中规模最大的金矿床,已探明金资源量5.8 t,矿体赋存于四平山组硅质岩、硅质角砾岩以及大塔山林场组流纹岩中。为了进一步厘定成岩成矿时代,阐释成矿过程,查明成岩成矿地球动力学背景,本文在四平山金矿床进行详细的野外调查基础上,以四平山组硅质岩、硅质角砾岩和大塔山林场组流纹岩为研究对象,开展赋矿围岩LA-ICP-MS锆石U-Pb定年和全岩主微量组成测试,以及含金石英脉流体包裹体热力学分析。结果表明,大塔山林场组流纹岩(SPS-H-002、SPS-H-009)的成岩年龄分别为(134±1)Ma和(123±1) Ma,金矿化时代略晚于流纹岩的成岩时代,属于早白垩世晚期;硅质岩和硅质角砾岩具有较高的SiO2含量,富集Cu、Ni、Ba元素而贫Co元素,ΣREE含量较低,轻重稀土分异程度不明显,具有铕正异常,形成于热水沉积作用;流纹岩具有高硅、富铝、贫钛锰磷和低Zr含量,为亚碱性过铝质钙碱性-高钾钙碱性系列岩石,轻稀土富集,重稀土亏损,具有明显的铕负异常,无铈异常,属于高分异S型花岗岩,可能为亏损地幔增生的年轻地壳物质部分熔融的产物;含金石英脉中流体包裹体大小介于5~12 μm之间,呈椭圆形和不规则形状成群或孤立分布,均一温度为118.7~223.4 ℃,盐度为0.40%~8.9%,密度为0.84~0.97 g/cm3,捕获压力为21.2~51.4 MPa, δD值为 -113.8‰~-84.0‰, δ18$O_{H_{2}O}$值为 -3.1‰~2.2‰,成矿流体以岩浆水为主,并显示出岩浆水与大气降水混合的特点。结合区域构造演化,认为四平山金矿床形成于碰撞后构造背景,成矿与古太平洋板块俯冲作用密切相关。

关键词: 那丹哈达地体, 四平山金矿床, 锆石 U-Pb 同位素, 地球化学, 古太平洋板块, 成矿构造背景

Abstract:

The Sipingshan gold deposit is located in the east Nadanhada terrane, which is the largest gold deposit in the terrane with a proven gold resource of 5.8 t in Hulin City, Heilongjiang Province.The ore body occurs in the cherts and silicified breccias in Sipingshan Formation, and the rhyolite in Datashanlinchang Formation.In this study, we aim to understand the metallogenic process and diagenetic and metallogenic geodynamics, and further determine the diagenetic and metallogenic ages.We conducted detailed field survey on the Sipingshan gold deposit and sampled the cherts and silicified breccias in Sipingshan Formation and rhyolite in Datashanlinchang Formation.Further, we carried out the zircon U-Pb dating using LA-ICP-MS technique and whole-rock major and trace element geochemistry on the ore-bearing surrounding rocks, and additionally we performed the thermodynamic analysis on the fluid inclusions in the gold-bearing quartz veins.The results indicate that the diagenetic ages of the rhyolite samples SPS-H-002 and SPS-H-009 in Datashanlinchang Formation are (134±1) Ma and (123±1) Ma, respectively.The gold mineralization age is slightly later than the that of the rhyolites, belonging to the late Early Cretaceous.Cherts and silicified breccias have a high SiO2 content, rich in Cu, Ni, and Ba elements but poor in Co element.Rare earth elements (REE) content is relatively lower in the rocks and the concentration difference between the light and heavy rare earth elements is not significant, with a europium positive anomaly possibly caused by hydrothermal sedimentation.Rhyolite belongs to a type of rock from subalkaline peraluminous calc-alkaline to high potassium calc-alkaline series, with high Si and Al contents but poor in Ti, Mn, P, and Zr contents.Those rocks are enriched in light REE but deficient in heavy REE, with an pronounced Eu negative anomaly but no Ce anomaly.They belong to highly differentiated S-type granite and may be the product of partial melting of young crustal material with depleted mantle accretion.The fluid inclusions in the gold-bearing quartz veins range from 5 to 12 μm in size, and with elliptical and irregular shapes in group or isolated distribution.Fluid inclusion study results in a homogeneous temperature of 119-223 ℃, salinity of 0.40%-8.9%, density of 0.84-0.97 g/cm3, and capture pressure of 21.2-51.4 MPa.The δD value of the gold-bearing quartz ranges from -113.8‰ to -84.0‰ and the δ18$O_{H_{2}O}$ value ranges from -3.1‰ to 2.2‰. The stable isotopes indicate that the ore-forming fluid has a magmatic origin and shows mixing characteristics of magmatic and meteoric water sources.Combined with the findings from the regional tectonic evolution, it can be concluded that the Sipingshan gold deposit was formed during the post collision and the gold mineralization is closely related to the subduction of the Pale-Pacific plate.

Key words: Nadanhada terrane, Sipingshan gold deposit, zircon geochronology, geochemistry, Pale-Pacific plate, metallogenic tectonics

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