Chapman, RJ, Allan, MM, Mortensen, JK et al. (2 more authors) (2018) A new indicator mineral methodology based on a generic Bi-Pb-Te-S mineral inclusion signature in detrital gold from porphyry and low/intermediate sulfidation epithermal environments in Yukon Territory, Canada. Mineralium Deposita, 53 (6). pp. 815-834. ISSN 0026-4598
Abstract
Porphyry-epithermal and orogenic gold are two of the most important styles of gold-bearing mineralization within orogenic belts. Populations of detrital gold resulting from bulk erosion of such regions may exhibit a compositional continuum wherein Ag, Cu, and Hg in the gold alloy may vary across the full range exhibited by natural gold. This paper describes a new methodology whereby orogenic and porphyry-epithermal gold may be distinguished according to the mineralogy of microscopic inclusions observed within detrital gold particles. A total of 1459 gold grains from hypogene, eluvial, and placer environments around calc-alkaline porphyry deposits in Yukon (Nucleus-Revenue, Casino, Sonora Gulch, and Cyprus-Klaza) have been characterized in terms of their alloy compositions (Au, Ag, Cu, and Hg) and their inclusion mineralogy. Despite differences in the evolution of the different magmatic hydrothermal systems, the gold exhibits a clear Bi-Pb-Te-S mineralogy in the inclusion suite, a signature which is either extremely weak or (most commonly) absent in both Yukon orogenic gold and gold from orogenic settings worldwide. Generic systematic compositional changes in ore mineralogy previously identified across the porphyry-epithermal transition have been identified in the corresponding inclusion suites observed in samples from Yukon. However, the Bi-Te association repeatedly observed in gold from the porphyry mineralization persists into the epithermal environment. Ranges of P-T-X conditions are replicated in the geological environments which define generic styles of mineralization. These parameters influence both gold alloy composition and ore mineralogy, of which inclusion suites are a manifestation. Consequently, we propose that this methodology approach can underpin a widely applicable indicator methodology based on detrital gold.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2017, The Author(s). This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
Keywords: | Gold; Indicator mineral; Microchemical characterization; Porphyry systems |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Institute for Applied Geosciences (IAG) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Jan 2018 14:02 |
Last Modified: | 27 Jul 2018 08:24 |
Status: | Published |
Publisher: | Springer Verlag |
Identification Number: | 10.1007/s00126-017-0782-0 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:125710 |