Toronto Geological Discussion Group



Upcoming events

    • 17 Jan 2017
    • 4:00 PM - 5:00 PM
    • 2nd Floor, 20 Toronto St
    • 31

    Evaluating the interplay of magmatism, tectonics, and basin redox in the genesis of the Wolverine volcanogenic massive sulfide (VMS) deposit, Yukon, Canada

    This presentation will also be accessible via online broadcast.

    The Wolverine volcanogenic massive sulfide (VMS) deposit, Yukon, is a unique natural laboratory to study the interrelationships of magma evolution, tectonics, and basin redox in the genesis of VMS deposits in volcanic- and sediment-rich extensional basins. Pre-VMS (~352 Ma) quartz-feldspar porphyries (QFP) have continental crust-like Nb/Ta ~12, eNdt = -7.1 to -11.5 (average = -10.6), and eHft = -12.2 to -20.8 (average = -16.5). The syn-VMS (~347 Ma) feldspar porphyries have higher high field strength element (HFSE) and rare earth element (REE) concnetration, and higher Nb/Ta (~17), eNdt = -7.8 to -8.1 (average = -8.0), and eHft = -13.6 to -18.0 (average = -14.8). Both suites have and Proterozoic (to Archean) depleted mantle model ages (1.59-2.58 Ga). In situ U-Pb on zircons illustrate that while some ages are close to previously reported concordant TIMS ages, most samples have evidence of inheritance with ages ranging from 348-381.7 Ma for the QFP suite and 368.9-370.5 Ma for the FP suite. In situ eHft values for the zircons range from -11.5 to -21.0 (average -15.3) and -11.6 to -26.0 (average = -18.7) for the QFP and FP, respectively. The chemical and isotopic shifts from the QFP to younger FP suite reflects the varying contributions from evolved continental crust versus juvenile basaltic melts, and can be accommodated within an evolving continental back-arc basin in which there was a progressive increase in mantle input as a result of upwelling of juvenile basaltic material beneath the back-arc basin as it opened. Notably, the upwelling of mafic magmatism and greater mantle components in the syn-VMS FP suite also coincided with higher temperature felsic magmatism and VMS deposit genesis.

    Shales intimately associated with the deposit, and with the porphyritic rhyolites, have redox sensitive trace element signatures (e.g., Mo-U, Corg-Ni systematics; Ni-V-Cr-Mn systematics) that indicate deposition under anoxic to sub-oxic conditions that were periodically euxinic with free H2S in the water column and the unconsolidated sediment pile. In contrast, shales proximal to the mineralized horizon have rare earth element and Y (REY) systematics (Ce/Ce*<<1 and Y/Ho>27) similar to oxygenated seawater. The Ce/Ce* values have a negative correlation with P2O5 and suggest a particulate shuttle control by detrital apatite that precipitated in the upper, oxygenated water column where it inherited an oxygenated seawater REE signature, which was then transported to the deeper water and deposited as detrital grains. The Ce/Ce* and Y/Ho values also correlate with CO2 and carbonate content of the shales. Moreover, the shales with the strongest oxygenated REY signatures and CO2-enrichment coincide with the strongest euxinic signatures. This paradox can be reconciled by enhanced deposition of apatite coincident with deposit formation, coupled with a late hydrothermal overprint on the shales from low temperature, CO2-rich (oxygenated?) hydrothermal fluids (i.e., high Y/Ho and Ce/Ce*<<1) in a vent-proximal environment.

    The presence of high temperature magmatism, extensional geodynamics, and a H2S-rich near-vent environment were critical for generating the Wolverine hydrothermal system and the resultant deposition of mineralization. Identification of similar tectonic environments with similar geological and geochemical features is critical for finding new resources along evolving continental margins.

    Speaker: Stephen Piercey

    Stephen J. Piercey completed BSc(Hons)(96) and MSc(98) degrees at Memorial University of Newfoundland, and a PhD from the University of British Columbia (2001). From 2001-2008 he was Assistant and Associate Professor at Laurentian University; from 2008-2009 he was a consulting geologist and principal of SJPGeoConsulting; and since 2009 he has been at Memorial University in the Department of Earth Sciences where he currently holds the rank of Professor. In addition, from 2009-2016 he held the NSERC-Altius Industrial Research Chair in Mineral Deposits at Memorial University. His research interests are in the application of field, geochemical, and mineralogical methods to obtain a craton- to nano-scale understanding of the genesis and exploration for mineral deposits, with particular emphasis on volcanogenic massive sulfide (VMS) and orogenic Au deposits, and the magmatic and tectonic evolution of orogenic belts. He and his research group have undertaken research in most provinces and territories in Canada and numerous jurisdictions internationally. He is a Fellow of the Geological Society of America, Association of Applied Geochemists, and Society of Economic Geologists. He is also a former winner of the Lindgren Medal of the Society of Economic Geologists; the William Harvey Gross Medal and the Howard Street Robinson Medal of the Mineral Deposits Division of the Geological Association of Canada; the Past President’s Medal of the Canadian Institute of Mining, Metallurgy, and Petrology; and the Teaching Award and the Early Achievement Award of the Professional Engineers and Geoscientists of Newfoundland and Labrador.

    • 31 Jan 2017
    • 4:00 PM - 5:00 PM
    • 2nd Floor, 20 Toronto St
    • 93

    Sergio Gelcich and Juan Carlos Ordonez, Hudbay Minerals

Past events

13 Dec 2016 Gahcho Kué Diamond Mine: The Long Road from Discovery to Production
24 Nov 2016 Mini-Symposium - Innovation and Change in Mineral Exploration
01 Nov 2016 Qiqavik: A New District Scale Au-Cu Camp in Nunavik, Quebec?
18 Oct 2016 Spectral, multispectral, hyperspectral: What works, what could work, and what will not work
27 Sep 2016 Ontario Geological Survey Geoscience Programs Update
13 Sep 2016 Structural Controls on Magmatic Ni-Cu-PGM Sulfide at Wallbridge Mining’s Parkin Offset Dyke Deposit in Sudbury, Ontario
17 May 2016 Transition Metals PGM-Ni-Cu Discoveries: Sunday Lake and Aer-Kidd, a Separation of 700 Kilometers and 700 Million Years
04 May 2016 Integrating multiple lines of evidence to define the exploration target range for the Castelo de Sonhos Paleo-placer gold Project, Brazil
19 Apr 2016 Mini-Symposium - The Big Bang: Understanding the Magmatic Controls of Mineral Deposits
05 Apr 2016 Alturas – A Recent High Sulphidation Gold Discovery on the El Indio Belt, Chile
18 Feb 2016 Geology and Mineralization of the New Afton alkalic porphyry Cu-Au deposit
10 Feb 2016 Murray Brook Polymetallic VHMS Deposit, Bathurst, New Brunswick
26 Jan 2016 From Sadiola to the recently discovered Boto Gold Deposit, 25 years of gold mining and exploration discovery in West Africa
15 Dec 2015 Mining Project Development Experience – Where Do Things Go Wrong and Why
18 Nov 2015 Mini-Symposium – Abitibi Gold: The next 135 million ounces
02 Nov 2015 TerraX Minerals Inc.
20 Oct 2015 Recent Advances in Ocean Mining
29 Sep 2015 55 Zone - A new high grade gold mine on the Yaramoko Property, Burkina Faso
14 Sep 2015 The Arrow Uranium Zone, a Rapidly Emerging Discovery - NexGen Energy Ltd.
05 May 2015 Brucejack Project,B.C.
18 Apr 2015 Mini-Symposium – Working Smart: Using the downturn in the economy as an opportunity
31 Mar 2015 The (geochemical) Hitchhikers’ Guide to Magmatic Ni-Cu Prospectivity in a Greenstone Belt
03 Feb 2015 Amaruq: The early days of a significant gold discovery
20 Jan 2015 The Renard Diamond Project: 13 Years From Discovery, Now Under Construction
09 Dec 2014 Facts and Fallacies: a personal commentary on the last 45 years of uranium exploration and development in the Athabasca Basin of northern Saskatchewan.
09 Dec 2014 Exploration for Deep VMS Ore Bodies: The Hudbay Lalor Case Study
19 Nov 2014 Mini-Symposium – Canada's Mineral Landscape: Aboriginal Rights and Related Issues
21 Oct 2014 The Geologic Framework and Potential for Deep Seated Deposits at the Superior Project, Ontario
07 Oct 2014 Hardrock Gold Project, Geraldton, Ontario: Structural and stratigraphic settings of the deposits
23 Sep 2014 Timing and Controls on Gold Mineralization in the Abitibi Greenstone Belt
15 Sep 2014 Deep Mineral Exploration - The Next Economic Geology Frontier
09 Sep 2014 The discovery of the Goldrush deposit, Cortez Camp, Nevada
13 May 2014 Alexkor and the Richtersveld Land Claim – A retrospective diamond mineral property valuation case study
29 Apr 2014 Advancing Canada's newest gold district: The Borden gold project
09 Apr 2014 Mini-Symposium – Mexico Exploration: Finding the Treasure of the Sierra Madre and more
18 Feb 2014 Geometallurgical Modelling of the Dumont Deposit
04 Feb 2014 The Pistol Bay Gold Project, Nunavut, Canada A new district of Archean gold deposits in a variety of rocks - not just iron formation!
21 Jan 2014 Deep Mining Exploration reveals Ancient Waters of the Precambrian Shield
10 Dec 2013 OSC Staff Notice 43-705: a fair reflection of the mining industry’s recent performance?
21 Nov 2013 Mini-Symposium – Applied Earth Modelling: Better Targeting Using 3D Exploration
05 Nov 2013 The Curraghinalt Orogenic Gold Deposit, Northern Ireland. A Pot of High Grade Gold at the End of the Rainbow
22 Oct 2013 A multidisciplinary approach to the Attawapiskat kimberlite field: accelerating the discovery to production pipeline
01 Oct 2013 Discovery of the Mesel, Batu Hijau, and Elang Deposits, Indonesia: Successful Greenfields Exploration
17 Sep 2013 Exploring and Developing the Hope Bay Project: Approaches Both Old and New
28 May 2013 Do Recent Changes to Ontario’s Mining Act Make the Province a Less Competitive Jurisdiction to Explore?
14 May 2013 Sabodala Gold Mine, Senegal
30 Apr 2013 Key Elements for Mineral Exploration Success: An Example from Neves-Corvo, Portugal
16 Apr 2013 The Rovina Valley Au-Cu Project, Golden Quadrilateral, Romania: New Discoveries in an Old Mining District
02 Apr 2013 Economic geology of black shale – hosted vanadium mineralization in Xiushui County, Jiangxi Province, southeastern China
26 Mar 2013 Mini-Symposium – Laterites or Laterwrongs: Making the Pieces Fit
19 Feb 2013 Anna Fonseca – Infrared Spectroscopy Applied to Alteration Mapping
05 Feb 2013 Joe Hinzer – Challenging Mineral Property Evaluations
22 Jan 2013 Jean-Francois Ravenelle – Geology of the Eleonore Gold Deposit
04 Dec 2012 Jeremy Niemi – The Romero gold discovery, Dominican Republic
08 Nov 2012 Mini-Symposium: The future of mining and exploration in Canada
23 Oct 2012 John Ryder – Paleoplacers – Are Archean/Proterozoic diamondiferous placers/paleoplacers potentially new sources of diamond supply to meet the looming diamond shortage?
09 Oct 2012 Warren Bates – Geology, alteration and Geophysics an the Manfo Gold Project, Sefwi Belt, Ghana
25 Sep 2012 Brent Cook – Exploration vs. Finance and the Low Odds of Success
11 Sep 2012 Hernan Ugalde – Geological Modeling of Geophysical Data: Beyond the 3D inversion black box, v2.0
18 Apr 2012 Hamid Mumin – Iron Oxide Copper-Gold Deposits in Genetic Context
03 Apr 2012 Sally Pehrsson – A new evolution and architecture for the Trans Hudson orogeny and its use in targeting for world class VMS, Nickel and Gold deposits
20 Mar 2012 Jim Mungall – Formation of iron oxide and phosphate tephra of the El Laco volcano, Chile from an Fe-P-O-S magma.
21 Feb 2012 Sergio Cattalani – Discovery and Development of the Canadian Malartic Bulk-Tonnage Gold Deposit, Southern Abitibi, Quebec, Canada.
07 Feb 2012 Workshop and Mini-Symposium on the Complexities of Grade Estimation
24 Jan 2012 Xiaodong Zhou – The Use and Limitations of Aster Satellite Imagery for Exploration

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