eCite Digital Repository

Multiple syngenetic metalliferous horizons enriched in V, As, Mo, Se, Ni, Ag, Zn and Au in the Northern Carlin Trend: Implications for the genesis of world class gold-arsenic deposits

Citation

Large, RR and Bull, SW and Gilbert, S, Multiple syngenetic metalliferous horizons enriched in V, As, Mo, Se, Ni, Ag, Zn and Au in the Northern Carlin Trend: Implications for the genesis of world class gold-arsenic deposits, Proceedings of the 6th Geological Society of Nevada Symposium: Great Basin Evolution and Metallogeny, 14-22 May 2010, Reno, Nevada, pp. 1-16. ISBN 9781605950402 (2011) [Refereed Conference Paper]


Preview
PDF
Restricted - Request a copy
3Mb
  

Copyright Statement

Copyright 2010 Geological Society of Nevada

Official URL: http://www.gsnv.org/publications/?itemid=10-1

Abstract

The source of the gold in the giant Carlin type deposits in Nevada is controversial; is it deeply sourced from the lower crust or mantle, from high level intrusions or from the sedimentary basin? We report new evidence that the Ordovician to Devonian carbonaceous stratigraphy that hosts the ore deposits is a viable source-rock for both gold and arsenic. Detailed studies of the host sediments away from the ore deposits has revealed at least seven metalliferous intervals of organic-rich mudstones in the stratigraphy from the base of the Roberts Mountains Formation to the top of the Rodeo Creek Formation. These intervals are enriched in syngenetic/diagenetic V, As, Mo, Se, Ni, Ag, Zn and Au and are termed the VAMSNAZ suite. These metals are preferentially concentrated in very fine grained aggregates of diagenetic pyrite, but some are also present in bedding parallel lenticles and cross cutting veins of bitumen. The metal association is typical of redox sensitive elements that are enriched in euxinic sedimentary environments by reduction and adsorption onto organic matter. Simple mass balance calculations suggest that these sediments may have contained sufficient metals to account for the entire budget of gold, arsenic and many of the other elements concentrated in the epigenetic Carlin ore deposits. Pre-enrichment of gold and arsenic in the Ordovician to Devonian slope and basin depositional facies of the Great Basin is proposed as a necessary requirement for the formation of the Carlin type ores in Nevada.

Item Details

Item Type:Refereed Conference Paper
Keywords:Carlin, syngenetic gold, VAMSNAZ, gold source rocks
Research Division:Earth Sciences
Research Group:Geology
Research Field:Ore Deposit Petrology
Objective Division:Mineral Resources (excl. Energy Resources)
Objective Group:Mineral Exploration
Objective Field:Precious (Noble) Metal Ore Exploration
Author:Large, RR (Professor Ross Large)
Author:Bull, SW (Dr Stuart Bull)
Author:Gilbert, S (Ms Sarah Gilbert)
ID Code:78367
Year Published:2011
Web of Science® Times Cited:1
Deposited By:Centre for Ore Deposit Research - CODES CoE
Deposited On:2012-06-24
Last Modified:2014-09-04
Downloads:8 View Download Statistics

Repository Staff Only: item control page