REE-Phosphate Chemistry for ISCG Exploration
| Autor: | Batch, Travis, Tiddy, Caroline, Brotodewo, Adrienne, Giles, David, Belperio, Antonio, Little, Glen |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| DOI: | 10.5281/zenodo.7955986 |
| Popis: | REE-bearing phosphates are common accessory minerals found in most geological environments. Of these minerals, monazite has the general chemistry AXO4 where A is usually a light rare earth element (REE) and X is typically P. It is easily altered by hydrothermal fluids, which are common ingredients of iron oxide-copper-gold (IOCG) and iron sulfide-copper-gold (ISCG) systems, forming hydrothermal monazite or rhabdophane. Rhabdophane (AXO4 * H2O) has the same stoichiometry as monazite but contains variable water and but is structurally distinct. Monazite can alter to rhabdophane in low-grade and retrograde alteration in the presence of hydrothermal fluids. The chemistry of hydrothermal REE-bearing phosphates can reflect that of hydrothermal fluids associated with mineralisation and can therefore be used as an indicator for proximity to mineralisation. Here we present the initial results from the Jericho iron sulfide-copper-gold (ISCG) deposit in Cloncurry, Australia using SEM and EPMA. At Jericho, hydrothermal REE-bearing phosphates can be completely distinguished from metamorphic REE-bearing phosphates based on Ca contents, and mostly discriminated between using Th and S contents. There is no chemical discriminator to differentiate between reprecipitated REE-bearing phosphates (REEbearing phosphates associated with apatite) and other hydrothermal REE-bearing phosphates. Hydrothermal REEbearing phosphates at Jericho typically have low EPMA totals, leading to the potential that it is rhabdophane. Open-Access Online Publication: May 22, 2023 |
| Databáze: | OpenAIRE |
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