地学前缘 ›› 2025, Vol. 32 ›› Issue (1): 91-104.DOI: 10.13745/j.esf.sf.2024.10.45

• 特提斯成矿带战略资源地球化学调查评价 • 上一篇    下一篇

巴基斯坦斑岩型铜矿地球化学特征与成矿潜力分析

张晶1,2(), 李天虎1,2, 王志华1,2, Naghmah HAIDER3, 洪俊1,2, 张辉善1,2, 梁楠1,2   

  1. 1.中国地质调查局 西安地质调查中心(西北地质科技创新中心), 陕西 西安 710100
    2.中国地质调查局 造山带地质研究中心, 陕西 西安 710100
    3.巴基斯坦地质调查局 国家实验室, 伊斯兰堡 44000
  • 收稿日期:2024-08-01 修回日期:2024-10-15 出版日期:2025-01-25 发布日期:2025-01-15
  • 作者简介:张 晶(1982—),女,硕士,正高级工程师,地球化学专业,主要从事勘查地球化学研究工作。E-mail: zhj884443@163.com
  • 基金资助:
    中国地质调查局项目“陆域地球化学调查(西安地调中心)”(DD20230248);“西部重点成矿带关键元素超常富集时空分布规律与战略资源效应”(U2244219);国家自然科学基金项目(92055314);国际地球科学计划项目(IGCP-741);中国科学院海外科教合作中心部署项目(046GJHZ2023071MI)

Geochemical characteristics and metallogenic potential analysis of porphyry copper deposits in Pakistan

ZHANG Jing1,2(), LI Tianhu1,2, WANG Zhihua1,2, Naghmah HAIDER3, HONG Jun1,2, ZHANG Huishan1,2, LIANG Nan1,2   

  1. 1. Xi’an Center(Science and Technology Innovation Center of Northwest of China), China Geological Survey, Xi’an 710100, China
    2. Orogenic Belt Geological Research Center, China Geological Survey, Xi’an 710100, China
    3. Advance Research Laboratories, Geological Survey of Pakistan, Islamabad 44000, Pakistan
  • Received:2024-08-01 Revised:2024-10-15 Online:2025-01-25 Published:2025-01-15

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摘要：

本文首次应用巴基斯坦国家尺度水系沉积物地球化学调查数据,分析了研究区铜元素地球化学背景和大型斑岩型铜矿区域地球化学特征及地球化学异常特征,分析了该区内主要地层、岩浆岩的地球化学特征。巴基斯坦主要基岩出露区铜元素平均值为23.48×10-6,背景值为18.6×10-6,与我国西北地区、青藏高原的铜元素丰度相当。与成矿斑岩体有关的岩浆岩主要为新生代酸性岩和中生代酸性岩,铜元素的地球化学平均值分别为39.09×10-6和28.28×10-6,富铜斑岩体是主要物质来源。应用1∶1 000 000国家尺度地球化学异常信息进行建模,元素组合为Cu、Au、Mo、Ag、Pb、Zn、Co和Cr,说明国家尺度地球化学异常对大型、超大型斑岩铜矿具有指示意义。以地球化学块体理论为基础,计算了铜异常的成矿有利度和致矿物质量,对区内铜资源量进行了预测和排序。在梳理典型斑岩型铜矿地球化学模型的基础上,以Cu、Mo、Au和Ag为主要指示元素,以Pb、Zn、Co和Cr为参考指示元素,结合地质背景圈定斑岩型铜矿找矿预测区4处,并对找矿预测区进行了成矿潜力分析。

关键词: 铜地球化学异常, 地球化学特征, 成矿潜力分析, 斑岩铜矿地球化学模型

Abstract:

The paper utilizes the geochemical data of stream sediments based on the national-scale (1∶1000000) geochemical mapping project in the outcrop area across Pakistan for the first time. This study aims to determine the geochemical background of copper in the study area, as well as the regional geochemical characteristics and geochemical anomalies associated with large porphyry copper deposits in Pakistan. The geochemical features of the main stratigraphic units and magmatic rocks within this region were examined. The average copper concentration in the outcrop areas of Pakistan is 23.48×10-6, with a background value of 18.6×10-6. This is comparable to the copper abundance found in northwest regions of China and the Tibetan Plateau. The magmatic rocks related to mineralization in porphyry systems are mainly Cenozoic and Mesozoic acid magmatic rocks, with average copper concentrations of 39.09×10-6 and 28.28×10-6, respectively, indicating that copper-rich porphyries are the main source of material. A modeling analysis of the elemental association of Cu, Au, Mo, Ag, Pb, Zn, Co and Cr has been conducted based on the national-scale geochemical data, indicating that the national-scale geochemical anomalies serve as indicators of large and super-large porphyry copper deposits. Based on the theory of geochemical block, the Pfd (Prospecting Favoralble Degress) and Qm (Quality of Mineral) were calculated and sorted by applying the principle and technical innovation of mineral resource potential prediction. On the basis of the geochemical model of typical porphyry copper deposits, with Cu, Mo, Au, Ag as primary indicator elements, and Pb, Zn, Co, Cr as secondary reference indicator elements, combined with the geological background, four prediction areas for porphyry copper deposits were identified. Furthermore, an analysis of the metallogenic potential of these identified prospecting areas was conducted.

Key words: geochemical anomaly of copper, geochemical characteristics, metallogenic potential analysis, geochemical model of porphyry copper deposits

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