The Toronto Geological Discussion Group

 

Events



Upcoming events

    • 23 Sep 2014
    • 4:00 PM - 5:00 PM
    • Twenty Toronto Street, Toronto, ON M5C 2B8
    • 78

    Timing and Controls on Gold Mineralization in the Abitibi Greenstone Belt


    And an update on the Mineral Exploration Research Centre (MERC), Department of Earth Sciences, Laurentian University

    John Ayer, PhD, PGeo; Associate Director, MERC


    Much of the Abitibi's gold production is from orogenic deposits controlled by late regional faulting and synorogenic sedimentary and volcanic units. These deposits young southward across the Abitibi. In the north; late tectonic assemblages consist of the ca. 2700 Ma Caopatina assemblage turbiditic sediments, unconformably overlain by sediments and alkalic volcanics of the ca. 2692 Ma Opemisca assemblage. In the NE Abitibi, gold mineralization associated with D1 is tightly constrained at 2697±1 Ma by mineralized and post-ore porphyry dikes. At the Detour Mine, D1 resulted in ca. 2725 Ma Deloro assemblage volcanics thrust over the Caopatina assemblage to the south along the Sunday Lake deformation zone (SLDZ). Subsequent oblique-slip deformation overprinted D1 with both dextral and sinistral components of displacement. Gold occurs in the hanging wall of the SLDZ in narrow high grade zones next to flexures along the faulted contact between the sediments and volcanics, and as broad, stockwork-disseminated lower grade zones in the hanging wall mafic flows. The age of a barren albitite dike cutting mineralization indicates that gold occurred around 2697 Ma.


    South-verging auriferous thrusts extend south to the Pipestone deformation zone (PDZ). Here, 2720-10 Ma Kidd Munro assemblage volcanics were thrust over the 2690-80 Ma Porcupine assemblage turbidites. Gold occurs in the hanging wall of the PDZ and in intrusions within the fault zone. The timing of D1 and gold mineralization is younger (i.e. <2680 Ma) than in the northern Abitibi. The Porcupine-Destor and Larder Lake-Cadillac deformation zones (PDDZ & LLCDZ) differ from more northerly structures in spatial association with younger sediments and alkalic volcanics of the Timiskaming assemblage (2676-70 Ma), and north-verging thrusting. Oblique-slip deformation overprinted the thrusting with sinistral followed by dextral displacements. Truncation of the PDZ by the PPDZ indicates the former is an older structure. Significant gold mineralization occurred at around 2665-60 Ma along the PDDZ and LLCDZ. Further to the south, in the Shining Tree area, molybdenite associated with gold mineralization in a breccia pipe has been dated as young as ca. 2630 Ma, further supporting the progressive southward younging and/or telescoping of gold events.     


    Controls on southward younging of tectonic events and gold mineralization are best explained by successive episodes of accretion of terranes proceeding from collision of the Abitibi with the Opatica in the north and culminating in collision with the Minnesota River Valley terrane to the south. Southward younging accretionary-related fault structures are thus considered the pathways for fluids bringing gold to the presently exposed crustal level.


    A smaller but significant amount of gold production is associated with earlier base metal  mineralization in VMS deposits and high level porphyry intrusions. The oldest is the Cote Gold Deposit associated with the 2740 Ma Chester Intrusive Complex in the Swayze belt.




    Bio: John Ayer, Associate Director at Mineral Exploration Research Centre, Laurentian University


    Education: 

    -BSc in Geology from Carleton University (1976)

    -MSc from Carleton University (1979)

    -PhD, University of Ottawa (1999). 

    Experience: 

    -Project geologist in exploration for a variety of mining companies across Canada (1979-1984).

    -Ontario Geological Survey (1984-2011); 

    -1:20 000 and 1:50 000 scale mapping of the Lake of the Woods greenstone belt, Wabigoon Subprovince (1984-1990).

    -1:20 000 and 1:50 000 scale mapping of the Northern Swayze greenstone belt, Abitibi Subprovince at (1990-1995).

    -Group Leader of the Precambrian Section Mapping Program in NE Ontario (1996 to 2011). Work included production of seven 1:100 000 scale compilation maps covering the Abitibi Greenstone belt in Ontario; OGS Representative on the Discover Abitibi Initiative and coordinator for the TGi-3 Abitibi Project in collaboration with the Geological Survey of Canada and Geology Quebec (2007-2011).

    -Associate Director of the Mineral Exploration Research Centre, Department of Earth Sciences, Laurentian University (2012-present).        


    Education:

    -BSc in Geology from Carleton University (1976)

    -MSc from Carleton University (1979)

    -PhD, University of Ottawa (1999).

    Experience:

    -Project geologist in exploration for a variety of mining companies across Canada (1979-1984).

    -Ontario Geological Survey (1984-2011);

                -1:20 000 and 1:50 000 scale mapping of the Lake of the Woods greenstone belt,             Wabigoon Subprovince (1984-1990).

                -1:20 000 and 1:50 000 scale mapping of the Northern Swayze greenstone belt, Abitibi             Subprovince at (1990-1995).

                -Group Leader of the Precambrian Section Mapping Program in NE Ontario (1996             to 2011). Work included production of seven 1:100 000 scale compilation maps             covering the Abitibi Greenstone belt in Ontario; OGS Representative on the Discover          Abitibi Initiative and coordinator for the TGi-3 Abitibi Project in collaboration with the           Geological Survey of Canada and Geology Quebec             (2007-2011).

    -Associate Director of the Mineral Exploration Research Centre, Department of Earth Sciences, Laurentian University (2012-present).        

    • 07 Oct 2014
    • 4:00 PM - 5:00 PM
    • Twenty Toronto Street, Toronto, ON M5C 2B8
    • 70

    Hardrock Gold Project, Geraldton, Ontario






    Bio: tba




    • 21 Oct 2014
    • 4:00 PM - 5:00 PM
    • Twenty Toronto Street, Toronto, ON M5C 2B8
    • 70

    The Geologic Framework and Potential for Deep Seated Deposits at the Superior Project, Ontario






    Bio: Morgan Quinn, Geologist, Superior Copper Corporation




    • 09 Dec 2014
    • 4:00 PM - 5:00 PM
    • Twenty Toronto Street, Toronto, ON M5C 2B8
    • 71

    Facts and Fallacies: a personal commentary on the last 45 years of uranium exploration and development in the Athabasca Basin of northern Saskatchewan.

    (1)  Economic development. 65% of known (>80) deposits are not in production and likely never will be - why not, and therefore what future discoveries may be economic?

    (2) The current exploration model. A severe case of EM myopia, so, what should explorers be focused on?


    This event is followed by our annual Christmas Networking event.



    Bio: Roger Wallis and Bill Kerr


    • 20 Jan 2015
    • 4:00 PM - 5:00 PM
    • Twenty Toronto Street, Toronto, ON M5C 2B8
    • 71

    Renard Mine, Quebec






    Bio: Matt Manson, CEO, President and Director, Stornoway Diamonds




    • 03 Feb 2015
    • 4:00 PM - 5:00 PM
    • Twenty Toronto Street, Toronto, ON M5C 2B8
    • 71
    Discovery History of the Cote Gold Deposit






    Bio: Jamie Rogers, Chief Geologist, IAMGOLD Corporation




    • 28 Apr 2015
    • 4:00 PM - 5:00 PM
    • tba
    • 71

    Abitibi Crustal Evolution





    Bio: Lyal Harris, INRS-ETE




Past events

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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