Apatite: A proxy to study oredeposits?

International audienceApatite (Ca5(PO4)3(OH, F, Cl)) is an ubiquitousaccessory mineral found in many types of rocks andenvironments. This mineral has several key featuresfor the characterization and/or the dating of fluidcirculation or magmatism responsible for theemplacement of mineralization:1. It often incorporates uranium during itscrystallization. This makes it an excellent candidatefor U-Pb dating. Moreover, apatite can also be datedby the fission tracks and (U-Th)/He methods.Therefore the same mineral can bring information onthe age of the mineralization and its exhumationhistory.2. Apatite is an excellent trap for the P, F, Cl,OH, but also for Rare Earth Elements (REE) [1].3. This mineral can easily react in the presence ofbrines, or aqueous fluids containing CO2, HCl, H2SO4and/or F [2].4. In many ore deposit, the crystallization ofapatite is contemporaneous with mineralizationprocesses [3].5. Its closure temperature with respect to the UPbsystem (375-550°C) gives it a peculiar role fordating hydrothermal events [4].Accordingly, apatite is, a priori, an excellentproxy for obtaining extensive information aboutmineralizing fluids and/or fertile magmas(temperatures, compositions and ages or durations ofthe events), information that is essential forestablishing a metallogenic model.We will present a comprehensive set of CLimaging, EPMA analyses, SIMS stable isotopes andU-Pb dating on apatite from several ore deposits inorder to assess the potential of this mineral for thestudy of ore deposits.[1] O’Really & Griffin & (2000). Lithos, 53, 217-232. [2] Pan & Fleet (2002). Rev in Mineral andGeochem, 48, 13-49. [3] Nyström & Henriquez(1994). Econ. Geol. 89, 820–839. [4] Blackburn et al.(2011). Contrib. Miner. Petrol. 162, 479–500