The Collahuasi district of northern Chile hosts several late Eocene-early Oligocene world-class porphyry Cu-Mo deposits, including Rosario, Ujina, and Quebrada Blanca deposits, and associated high-sulfidation epithermal mineralization at La Grande. Mineralization is hosted by intermediate to felsic intrusive and volcanic rocks of the upper Paleozoic to Lower Triassic Collahuasi Group, which experienced lower greenschist facies regional metamorphism prior to mineralization. Extensive hydrothermal alteration zones surround the porphyry and epithermal deposits, associated with hypogene ore-forming processes. However, outside of the observed sulfide halo the limits of geochemical anomalism associated with mineralization are difficult to define due to mineralogical similarities between weak, distal propylitic alteration and regional metamorphism affecting the host rocks. Recent advancements in laser ablation-inductively coupled plasma-mass spectrometry analysis of epidote from hydrothermal alteration zones around porphyry and skarn deposits have shown that low-level hypogene geochemical anomalies can be detected at distances farther from the center of mineralization than by conventional rock chip sampling. Selective analysis of propylitic epidote from the Collahuasi district indicates that anomalous concentrations of distal pathfinder elements in epidote, including As (>50 ppm), Sb (>25 ppm), Pb (>100 ppm), and Mn (>5,000 ppm), were detectable 1.5 to 4.0 km from deposit centers. Significantly, the concentrations of these trace elements in epidote were obtained from samples that contained whole-rock concentrations of

中文翻译：

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绿帘石微量元素化学作为智利北部 Collahuasi 区的勘探工具

智利北部的 Collahuasi 地区拥有多个晚始新世-早渐新世世界级斑岩铜钼矿床，包括 Rosario、Ujina 和 Quebrada Blanca 矿床，以及 La Grande 的相关高硫化超热液矿化。成矿由上古生界至下三叠统 Collahuasi 群的中长英质侵入岩和火山岩承载，在成矿前经历了下绿片岩相区域变质作用。广泛的热液蚀变带围绕着斑岩和超热液矿床，与下成矿过程有关。然而，在观察到的硫化物晕之外，由于弱、影响寄主岩的远端青岩蚀变和区域变质作用。对来自斑岩和矽卡岩矿床周围热液蚀变带的绿帘石进行激光烧蚀电感耦合等离子体质谱分析的最新进展表明，与常规岩屑采样相比，可以在距矿化中心更远的距离处检测到低水平的下成因地球化学异常. 对来自 Collahuasi 地区的青岩绿帘石的选择性分析表明绿帘石中远端探路者元素的浓度异常，包括 As (>50 ppm)、Sb (>25 ppm)、Pb (>100 ppm) 和 Mn (>5,000 ppm)，在距矿床中心 1.5 至 4.0 公里处可检测到。值得注意的是，绿帘石中这些微量元素的浓度是从包含全岩浓度的样品中获得的