The chemistry of hydrothermal monazite from the Carrapateena and Prominent Hill iron oxide-copper-gold (IOCG) deposits in the IOCG-rich Gawler Craton, South Australia, is used here to define geochemical criteria for IOCG exploration in the Gawler Craton as follows: Monazite associated with IOCG mineralisation: La + Ce > 63 wt% (where La > 22.5 wt% and Ce > 37 wt%), Y and/or Th < 1 wt% and Nd < 12.5 wt%; Intermediate composition monazite (between background and ore-related compositions): 45 wt% < La + Ce < 63 wt%, Y and/or Th < 1 wt%. Intermediate monazite compositions preserving Nd > 12.5 wt% are considered indicative of Carrapateena-style mineralisation; Background compositions: La + Ce < 45 wt% or Y or Th > 1 wt%. Mineralisation-related monazite compositions are recognised within monazite hosted within cover sequence materials that directly overly IOCG mineralisation at Carrapateena. Similar observations have been made at Prominent Hill. Recognition of these signatures within cover sequence materials demonstrates that the geochemical signatures can survive processes of weathering, erosion, transport and redeposition into younger cover sequence materials that overlie older, mineralised basement rocks. The monazite geochemical signatures therefore have the potential to be dispersed within the cover sequence, effectively increasing the geochemical footprint of mineralisation.

中文翻译：

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独居石作为南澳大利亚高勒克拉通氧化铁-铜-金矿化的勘探工具

来自南澳大利亚富含 IOCG 的 Gawler Craton 的 Carrapateena 和 Prominent Hill 氧化铁-铜-金 (IOCG) 矿床的热液独居石的化学性质在此用于定义 Gawler Craton IOCG 勘探的地球化学标准如下：与 IOCG 矿化相关：La + Ce > 63 wt%（其中 La > 22.5 wt% 和 Ce > 37 wt%），Y 和/或 Th < 1 wt% 和 Nd < 12.5 wt%；中间成分独居石（介于背景成分和矿石相关成分之间）：45 wt% < La + Ce < 63 wt%，Y 和/或 Th < 1 wt%。保留 Nd > 12.5 wt% 的中间独居石组合物被认为是 Carrapateena 型矿化的指示；背景成分：La + Ce < 45 wt% 或 Y 或 Th > 1 wt%。与矿化相关的独居石成分在位于 Carrapateena 的直接覆盖 IOCG 矿化的覆盖序列材料中的独居石中被识别。在 Prominent Hill 也有类似的观察。对覆盖层序材料中的这些特征的识别表明，地球化学特征可以在风化、侵蚀、运输和再沉积为覆盖在较旧矿化基底岩上的较年轻的覆盖层序材料的过程中幸存下来。因此，独居石地球化学特征有可能分散在覆盖层序列中，有效地增加矿化的地球化学足迹。对覆盖层序材料中的这些特征的识别表明，地球化学特征可以在风化、侵蚀、运输和再沉积为覆盖在较旧矿化基底岩上的较年轻的覆盖层序材料的过程中幸存下来。因此，独居石地球化学特征有可能分散在覆盖层序列中，有效地增加矿化的地球化学足迹。对覆盖层序材料中的这些特征的识别表明，地球化学特征可以在风化、侵蚀、运输和再沉积为覆盖在较旧矿化基底岩上的较年轻的覆盖层序材料的过程中幸存下来。因此，独居石地球化学特征有可能分散在覆盖层序列中，有效地增加矿化的地球化学足迹。