The sorosilicate mineral epidote is a commonly occurring and easily recognisable mineral found within the alteration halo surrounding mineralised hydrothermal deposits that are hosted in volcano-sedimentary and igneous terranes. Epidote is also a product of greenschist and amphibolite facies regional metamorphism. As a result, in ancient arc-volcanic terranes it can be unclear whether epidote encountered during regional exploration has formed via metamorphic or magmatic-hydrothermal processes. In this study, we compare mineral chemical analyses of epidote from regional metamorphic terranes with epidote sampled from the hydrothermal alteration halos surrounding porphyry and skarn mineralisation in the Baguio district, Philippines. The results are subsequently used to test the ‘fertility’ of epidote-bearing samples collected from the Aconcagua river valley of central Chile. It was determined that there are measurable differences in trace and rare earth element chemistry that can be used to effectively discriminate between epidote formed from regional metamorphism and hydrothermal alteration related to mineralisation. The ability to geochemically distinguish between these two styles of epidote has substantial implications for mineral exploration in regionally metamorphosed terranes, as well as for situations where porphyry-style mineralisation is not exposed at surface.
Funding
Australian Research Council
AMIRA International Ltd
BHP Billiton Ltd
Newcrest Mining Limited
History
Publication title
Proceedings of the 14th SGA Biennial Meeting: Mineral Resources to Discover
Editors
P Mercier-Langevin, B Dube, M Bardoux, P-S Ross, C Dion
Pagination
1069-1071
ISBN
9782981689801
Department/School
School of Natural Sciences
Publisher
Society for Geology Applied to Mineral Deposits
Place of publication
Switzerland
Event title
14th SGA Biennial Meeting
Event Venue
Quebec City, Canada
Date of Event (Start Date)
2017-08-20
Date of Event (End Date)
2017-08-23
Rights statement
Copyright 2017 Society for Geology Applied to Mineral Deposits