Fluorine and PGE-Au elevated signature of alkaline magmas from the Yilgarn Craton

insights into mantle fertility

Eunjoo Choi, Marco Fiorentini, Andrea Giuliani, Stephen Foley

Research output: Chapter in Book/Report/Conference proceedingConference abstract

Abstract

Our current understanding of the nature of the mantle, under the Archean Yilgarn Craton, Western Australia is predominantly based on the image provided by a number of geophysical datasets and on the radiogenic isotope (e.g., Lu-Hf, Sm-Nd) composition of granitoid and ultramafic rocks. The PGE-Au signature of deeply sourced alkaline magmas may provide key insights into the metallogenic fertility of the mantle underlying the Yilgarn Craton. The Yilgarn Craton contains various types of alkaline rocks, including calc-alkaline lamprophyres (CAL), ultramafic lamprophyres (UML), carbonatites, orangeites and kimberlites. The PGE patterns of the CAL exhibit elevated (Pd/Ir)N ratios, whereas the other rock types are characterised by less fractionated PGE patterns, with lower (Pd/Ir)(N) ratios. In general, most alkaline magmas from the Yilgarn Craton appear to be anomalously enriched in Au. Furthermore, their key constituent magmatic minerals, such as amphibole, mica and apatite are anomalously enriched in F, and S. These volatiles may play a crucial role in the transport and concentration of precious metals from the mantle into the crust, contributing to explaining its exceptional metal endowment.

Original languageEnglish
Title of host publicationProceedings of the 15th SGA Biennial Meeting, 27-30 August 2019, Glasgow, Scotland
PublisherThe Society for Geology Applied to Mineral Deposits (SGA)
Pages538-541
Number of pages4
Volume2
ISBN (Print)9780852619636
Publication statusPublished - 2019
EventBiennial SGA Meeting (15th : 2019): Life with Ore Deposits on Earth - Glasgow
Duration: 27 Aug 201930 Aug 2019

Conference

ConferenceBiennial SGA Meeting (15th : 2019)
CityGlasgow
Period27/08/1930/08/19

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