Linking gold mineralization to regional-scale drivers of mineral systems using in situ U-Pb geochronology and pyrite LA-ICP-MS element mapping

Imogen O. H. Fielding, Simon P. Johnson, Sebastien Meffre, Jianwei Zi, Stephen Sheppard, Ross R. Large, Birger Rasmussen

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Proterozoic orogens commonly host a range of hydrothermal ores that form in diverse tectonic settings at different times. However, the link between mineralization and the regional-scale tectonothermal evolution of orogens is usually not well understood, especially in areas subject to multiple hydrothermal events. Regional-scale drivers for mineral systems vary between the different classes of hydrothermal ore, but all involve an energy source and a fluid pathway to focus mineralizing fluids into the upper crust. The Mount Olympus gold deposit in the Proterozoic Capricorn Orogen of Western Australia, was regarded as an orogenic gold deposit that formed at ca. 1738 Ma during the assembly of Proterozoic Australia. However, the trace element chemistry of the pyrite crystals closely resembles those of the Carlin deposits of Nevada, with rims that display solid solution gold accompanied by elevated As, Cu, Sb, Hg, and TI, surrounding gold-poor cores. New SHRIMP U-Pb dating of xenotime intergrown with auriferous pyrite and ore-stage alteration minerals provided a weighted mean (207)pb*/(206)pb* date of 1769 +/- 5 Ma, interpreted as the age of gold mineralization. This was followed by two discrete episodes of hydrothermal alteration at 1727 +/- 7 Ma and 1673 +/- 8 Ma. The three ages are linked to multiple reactivation of the crustal-scale Nanjilgardy Fault during repeated episodes of intracratonic reworking. The regional-scale drivers for Carlin-like gold mineralization at Mount Olympus are related to a change in tectonic regime during the final stages of the intracratonic 1820-1770 Ma Capricorn Orogeny. Our results suggest that substantial sized Carlin-like gold deposits can form in an intracratonic setting during regional-scale crustal reworking. (C) 2018, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V.

Original languageEnglish
Pages (from-to)89-105
Number of pages17
JournalGeoscience Frontiers
Volume10
Issue number1
DOIs
Publication statusPublished - Jan 2019

Cite this

Fielding, Imogen O. H. ; Johnson, Simon P. ; Meffre, Sebastien ; Zi, Jianwei ; Sheppard, Stephen ; Large, Ross R. ; Rasmussen, Birger. / Linking gold mineralization to regional-scale drivers of mineral systems using in situ U-Pb geochronology and pyrite LA-ICP-MS element mapping. In: Geoscience Frontiers. 2019 ; Vol. 10, No. 1. pp. 89-105.
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Linking gold mineralization to regional-scale drivers of mineral systems using in situ U-Pb geochronology and pyrite LA-ICP-MS element mapping. / Fielding, Imogen O. H.; Johnson, Simon P.; Meffre, Sebastien; Zi, Jianwei; Sheppard, Stephen; Large, Ross R.; Rasmussen, Birger.

In: Geoscience Frontiers, Vol. 10, No. 1, 01.2019, p. 89-105.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Linking gold mineralization to regional-scale drivers of mineral systems using in situ U-Pb geochronology and pyrite LA-ICP-MS element mapping

AU - Fielding, Imogen O. H.

AU - Johnson, Simon P.

AU - Meffre, Sebastien

AU - Zi, Jianwei

AU - Sheppard, Stephen

AU - Large, Ross R.

AU - Rasmussen, Birger

PY - 2019/1

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N2 - Proterozoic orogens commonly host a range of hydrothermal ores that form in diverse tectonic settings at different times. However, the link between mineralization and the regional-scale tectonothermal evolution of orogens is usually not well understood, especially in areas subject to multiple hydrothermal events. Regional-scale drivers for mineral systems vary between the different classes of hydrothermal ore, but all involve an energy source and a fluid pathway to focus mineralizing fluids into the upper crust. The Mount Olympus gold deposit in the Proterozoic Capricorn Orogen of Western Australia, was regarded as an orogenic gold deposit that formed at ca. 1738 Ma during the assembly of Proterozoic Australia. However, the trace element chemistry of the pyrite crystals closely resembles those of the Carlin deposits of Nevada, with rims that display solid solution gold accompanied by elevated As, Cu, Sb, Hg, and TI, surrounding gold-poor cores. New SHRIMP U-Pb dating of xenotime intergrown with auriferous pyrite and ore-stage alteration minerals provided a weighted mean (207)pb*/(206)pb* date of 1769 +/- 5 Ma, interpreted as the age of gold mineralization. This was followed by two discrete episodes of hydrothermal alteration at 1727 +/- 7 Ma and 1673 +/- 8 Ma. The three ages are linked to multiple reactivation of the crustal-scale Nanjilgardy Fault during repeated episodes of intracratonic reworking. The regional-scale drivers for Carlin-like gold mineralization at Mount Olympus are related to a change in tectonic regime during the final stages of the intracratonic 1820-1770 Ma Capricorn Orogeny. Our results suggest that substantial sized Carlin-like gold deposits can form in an intracratonic setting during regional-scale crustal reworking. (C) 2018, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V.

AB - Proterozoic orogens commonly host a range of hydrothermal ores that form in diverse tectonic settings at different times. However, the link between mineralization and the regional-scale tectonothermal evolution of orogens is usually not well understood, especially in areas subject to multiple hydrothermal events. Regional-scale drivers for mineral systems vary between the different classes of hydrothermal ore, but all involve an energy source and a fluid pathway to focus mineralizing fluids into the upper crust. The Mount Olympus gold deposit in the Proterozoic Capricorn Orogen of Western Australia, was regarded as an orogenic gold deposit that formed at ca. 1738 Ma during the assembly of Proterozoic Australia. However, the trace element chemistry of the pyrite crystals closely resembles those of the Carlin deposits of Nevada, with rims that display solid solution gold accompanied by elevated As, Cu, Sb, Hg, and TI, surrounding gold-poor cores. New SHRIMP U-Pb dating of xenotime intergrown with auriferous pyrite and ore-stage alteration minerals provided a weighted mean (207)pb*/(206)pb* date of 1769 +/- 5 Ma, interpreted as the age of gold mineralization. This was followed by two discrete episodes of hydrothermal alteration at 1727 +/- 7 Ma and 1673 +/- 8 Ma. The three ages are linked to multiple reactivation of the crustal-scale Nanjilgardy Fault during repeated episodes of intracratonic reworking. The regional-scale drivers for Carlin-like gold mineralization at Mount Olympus are related to a change in tectonic regime during the final stages of the intracratonic 1820-1770 Ma Capricorn Orogeny. Our results suggest that substantial sized Carlin-like gold deposits can form in an intracratonic setting during regional-scale crustal reworking. (C) 2018, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V.

KW - Geochronology

KW - Xenotime

KW - SHRIMP

KW - LA-ICP-MS

KW - Gold mineralization

KW - Capricorn orogen

KW - OROGENIC GOLD

KW - WESTERN-AUSTRALIA

KW - CAPRICORN OROGEN

KW - DEPOSITS

KW - XENOTIME

KW - REWORKING

KW - EVOLUTION

KW - MONAZITE

KW - EXAMPLE

KW - ORIGIN

U2 - 10.1016/j.gsf.2018.06.005

DO - 10.1016/j.gsf.2018.06.005

M3 - Article

VL - 10

SP - 89

EP - 105

JO - Geoscience Frontiers

JF - Geoscience Frontiers

SN - 1674-9871

IS - 1

ER -