The mineral chemistry of epidote and chlorite from the propylitic halo at El Teniente, in samples collected at distances up to 6.6 km from the deposit center, was determined by microprobe and laser ablation-inductively coupled plasma-mass spectrometry. Results show that both minerals systematically incorporated a range of trace elements that define a much larger footprint to the system than is easily recognized using conventional means such as whole-rock geochemistry. Apart from Fe and Mg in chlorite, there is no significant control of mineral chemistry by bulk-rock composition. For chlorite, geothermometry temperatures and Ti and V concentrations are high proximal, whereas Li, As, Co, Sr, Ca, and Y are low proximal and elevated in distal positions. Ratios of these elements define gradients toward ore varying over three to five orders of magnitude. The proximal-high Ti content is thought to reflect crystallization temperature, whereas proximal-low signatures are believed to characterize elements that are relatively fluid mobile in the inner parts of the propylitic halo in the presence of mildly alkaline to mildly acidic and oxidized fluids so that they are not incorporated into crystallizing chlorite, despite being generally compatible within the mineral structure. These elements begin to substitute into chlorite in the distal parts of the propylitic halo where fluids are largely rock buffered in terms of major element chemistry. In epidote, As defines a broad proximal low and is generally elevated at distances of at least 3 km from the edge of the ore shell. Zinc, La, Yb, Y, and Zr in epidote, among others, appear to define a geochemical shoulder that surrounds the deposit. These patterns are broadly similar to those observed in previous work at Batu Hijau and in the Baguio district, suggesting that these minerals behave consistently in porphyry systems and can therefore provide useful exploration tools within propylitic green rocks.

中文翻译：

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使用丙稀石矿物化学在斑岩铜系统中进行勘探目标：智利 El Teniente 矿床的案例研究

在距矿床中心 6.6 公里处收集的样品中，来自 El Teniente 的青绿岩晕的绿帘石和绿泥石的矿物化学是通过微探针和激光烧蚀电感耦合等离子体质谱法测定的。结果表明，这两种矿物系统地结合了一系列微量元素，这些元素为系统定义了比使用全岩地球化学等传统方法容易识别的更大的足迹。除了绿泥石中的 Fe 和 Mg 之外，大块岩石的成分对矿物化学没有显着控制。对于绿泥石，地球测温温度和 Ti 和 V 浓度在近端较高，而 Li、As、Co、Sr、Ca 和 Y 在近端较低，而在远端位置较高。这些元素的比率定义了在三到五个数量级上变化的矿石梯度。近端高的 Ti 含量被认为反映了结晶温度，而近端低的特征被认为表征了在弱碱性到弱酸性和氧化流体存在的情况下，在青橄榄岩晕内部具有相对流动性的元素，因此尽管它们在矿物结构中通常是相容的，但它们不会被纳入结晶的绿泥石中。这些元素开始在青橄榄岩晕的远端部分取代绿泥石，那里的流体在主要元素化学方面主要由岩石缓冲。在绿帘石中，As 定义了一个宽阔的近端低洼，通常在距矿壳边缘至少 3 公里的距离处升高。绿帘石中的锌、La、Yb、Y 和 Zr 等似乎定义了围绕矿床的地球化学肩峰。