The Rice Lake greenstone belt: geology overview and update …...The Rice Lake greenstone belt:...
Transcript of The Rice Lake greenstone belt: geology overview and update …...The Rice Lake greenstone belt:...
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The Rice Lake greenstone belt:geology overview and update
of MGS activities
The Rice Lake greenstone belt:The Rice Lake greenstone belt:geology overview and update geology overview and update
of MGS activitiesof MGS activities
Manitoba Mining & Minerals Convention 2007Manitoba Mining & Minerals Convention 2007
Scott AndersonManitoba Geological Survey
Scott AndersonScott AndersonManitoba Geological SurveyManitoba Geological Survey
Sunrise, Gem Lake
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PresentationoutlinePresentationoutline
• Regional setting• Regional setting
Banksian L.
• Local geology;lithotectonic assemblages
• Local geology;lithotectonic assemblages
• Structural evolution• Structural evolution
• Metallogeny and exploration potential• Metallogeny and exploration potential
• Recent exploration• Recent exploration
• Ongoing MGS activities• Ongoing MGS activities
SanGold #3 zone
Manigotagan R.
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Manit
oba
Ontar
io
Wabigoon
Uchi
Winnipeg R.
Berens River
Oxford-Stull
LakeWinnipeg
Northern Superior
English R.
Quetico
WawaLak
e
pSu erior
Island L.
Munro
3.5- 2.81 Ga Northern Superior superterrane
3.0 - 2.87 Ga North Caribou terrane3.17 - 2.81 Ga Winnipeg River terrane
Mainly oceanic affinity
Mainly continental affinity
Meta-sedimentary belt
Granitoid rocks
> 2.8 Ga continental terranes and isotopic influence
Greenstone belts
200 km
Manit
oba
Ontar
io
Wabigoon
Uchi
Winnipeg R.
Berens River
Oxford-Stull
LakeWinnipeg
Northern Superior
English R.
Quetico
WawaLak
e
pSu erior
Island L.
Munro
3.5- 2.81 Ga Northern Superior superterrane
3.0 - 2.87 Ga North Caribou terrane3.17 - 2.81 Ga Winnipeg River terrane
Mainly oceanic affinity
Mainly continental affinity
Meta-sedimentary belt
Granitoid rocks
> 2.8 Ga continental terranes and isotopic influence
Greenstone belts
200 km
Western SuperiorProvince:
regional setting
Western SuperiorProvince:
regional setting
Western Superior Province• Prolific host to
Orogenic Au• Also hosts:
VHMS Cu-Pb-Zn(Au,Ag)Magmatic Ni-Cu-PGEPegmatite Li-Cs-Ta
Western Superior Province• Prolific host to
Orogenic Au• Also hosts:
VHMS Cu-Pb-Zn(Au,Ag)Magmatic Ni-Cu-PGEPegmatite Li-Cs-Ta
NCTNCT
RICE LAKE BELTRICE LAKE BELT
RED LAKE BELTRED LAKE BELT
NATMAPNATMAP
ERBERB
• north-verging subductionaccretion complex alongsouth margin of NCT
• north-verging subductionaccretion complex alongsouth margin of NCT
UCHIUCHI
* Percival et al., 2006: CJES, v. 43, p. 1085-1117.* Percival et al., 2006: CJES, v. 43, p. 1085-1117.
NCTNCT
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Rice Lake belt: general geologyRice Lake belt: general geology
NORTH CARIBOUNORTH CARIBOU
UCHIUCHI
ENGLISH RIVERENGLISH RIVER
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Wallace assemblage• quartzite, conglomerate,
iron formation, carbonate,komatiite
• 2.92 Ga (Davis, 1994; Sasseville et al., 2006)• shallow subaqueous
continental platform
Wallace assemblage• quartzite, conglomerate,
iron formation, carbonate,komatiite
• 2.92 Ga (Davis, 1994; Sasseville et al., 2006)• shallow subaqueous
continental platform
Initial rifting of NCT (ca. 3.0 Ga)Initial rifting of NCT (ca. 3.0 Ga)
Red Lake equivalent: BalmerRed Lake equivalent: BalmerBedded calcsilicateBedded calcsilicate
Fuchsitic quartziteFuchsitic quartzite
T. CorkeryT. Corkery
A. BailesA. Bailes
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Northward subduction and plumemagmatism beneath NCT margin
Northward subduction and plumemagmatism beneath NCT margin
Dacite brecciaDacite breccia
Spinifex komatiiteSpinifex komatiite
Red Lake equivalent:Bruce Channel/Trout Bay
Red Lake equivalent:Bruce Channel/Trout Bay
Garner assemblage• CA dacite, layered ultramafic
intrusion, iron formation,komatiite to Mg-THOL basalt
• ca. 2.87-2.90 Ga (Davis, 1994;Anderson, unpubl.)
• subaqueous continental arcto intra-arc basin
Garner assemblage• CA dacite, layered ultramafic
intrusion, iron formation,komatiite to Mg-THOL basalt
• ca. 2.87-2.90 Ga (Davis, 1994;Anderson, unpubl.)
• subaqueous continental arcto intra-arc basin
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Andesite-dacite brecciaAndesite-dacite breccia
Arc – back-arc complex; northward subduction
beneath NCT margin
Arc – back-arc complex; northward subduction
beneath NCT margin
Bidou assemblage• Mg-THOL basalt, epiclastic
rocks, gabbro• 2.724-2.745 Ga (Anderson, unpubl.)• CA dacite, andesite, basalt;
epiclastic rocks, gabbro• 2.715-2.73 Ga (Turek et al., 1989;
Anderson, unpubl.)• subaqueous marginal-arc
and back-arc basin
Bidou assemblage• Mg-THOL basalt, epiclastic
rocks, gabbro• 2.724-2.745 Ga (Anderson, unpubl.)• CA dacite, andesite, basalt;
epiclastic rocks, gabbro• 2.715-2.73 Ga (Turek et al., 1989;
Anderson, unpubl.)• subaqueous marginal-arc
and back-arc basin
Pillowed basaltPillowed basalt Greywacke and chertGreywacke and chert
Red Lake equivalent: Confederation Red Lake equivalent: Confederation
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Restricted extensional basin in Bidou arc
Restricted extensional basin in Bidou arc
Gem assemblage• trans. CA-THOL rhyolite,
dacite, basaltic andesite;epiclastic rocks
• ca. 2.72 Ga (Davis, 1994; Anderson, unpubl.)
• subaerial to shallow-subaqueous arc-rift setting
Gem assemblage• trans. CA-THOL rhyolite,
dacite, basaltic andesite;epiclastic rocks
• ca. 2.72 Ga (Davis, 1994; Anderson, unpubl.)
• subaerial to shallow-subaqueous arc-rift setting
Flow-banded rhyoliteFlow-banded rhyolite
Rhyolite flow-lobe brecciaRhyolite flow-lobe brecciaUchi equivalent: St. Joseph(?) Uchi equivalent: St. Joseph(?)
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Edmunds assemblage• proximal equivalent to ERB
metasedimentary rocks• turbiditic greywacke, mudstone,
conglomerate, iron formation• 2.696 Ga (McNicoll and Rogers, unpubl.)• marine-deltaic setting
Edmunds assemblage• proximal equivalent to ERB
metasedimentary rocks• turbiditic greywacke, mudstone,
conglomerate, iron formation• 2.696 Ga (McNicoll and Rogers, unpubl.)• marine-deltaic setting
Polymictic conglomeratePolymictic conglomerate
Greywacke-mudstone turbiditesGreywacke-mudstone turbidites
Uchi equivalent: none known? Uchi equivalent: none known?
Post-accretion, pre-orogenicdenudation of NCT margin
Post-accretion, pre-orogenicdenudation of NCT margin
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San Antonio assemblage• quartz greywacke, quartzite,
conglomerate, turbiditicgreywacke
•
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Structural evolution: central Rice Lake beltStructural evolution: central Rice Lake belt* PMAP2005-1
SAASAA
Angular unconformity (G1)Angular unconformity (G1)
G2 thrustG2 thrust
G3 foldsG3 folds
G4-G5 high-strain zonesG4-G5 high-strain zonesG4-G5 high-strain zonesG4-G5 high-strain zones
G6 foldG6 fold
Protracted (ca. 300 Ma) magmaticand depositional history
+Complex structural
evolution=
Favourable metallogenicsetting
Protracted (ca. 300 Ma) magmaticand depositional history
+Complex structural
evolution=
Favourable metallogenicsetting
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Orogenic lode-goldOrogenic lode-gold
Dube et al., 2007Dube et al., 2007
Significant gold endowment:• over 200 occurrences• 5 significant producers (>50k ounces);
over 1.7 million ounces total production• Rice Lake deposit (~2.3 million ounces)• multiple styles of mineralization
Significant gold endowment:• over 200 occurrences• 5 significant producers (>50k ounces);
over 1.7 million ounces total production• Rice Lake deposit (~2.3 million ounces)• multiple styles of mineralization
Favourable setting:• accretionary plate-margin• crustal scale faults• regional greenschist-facies metamorphism• extensive CO2 alteration• chemically favourable rock-types• complex stratigraphy and structure
Favourable setting:• accretionary plate-margin• crustal scale faults• regional greenschist-facies metamorphism• extensive CO2 alteration• chemically favourable rock-types• complex stratigraphy and structure
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Base metalsBase metals
Pyroxeniteintrusion brecciaWeber, 1990
Pyroxeniteintrusion brecciaWeber, 1990
Magmatic Ni-Cu-PGE • English L., Jeep, Garner
intrusions• mafic to ultramafic layered
intrusions or complexintrusion breccias
• Jeep and English Lakeoccurrences
Magmatic Ni-Cu-PGE • English L., Jeep, Garner
intrusions• mafic to ultramafic layered
intrusions or complexintrusion breccias
• Jeep and English Lakeoccurrences
FIII high-silicarhyolite dome (Gem)
FIII high-silicarhyolite dome (Gem)
VHMS-stylemineralization (Bidou)
VHMS-stylemineralization (Bidou)
Volcanic-hosted massive sulphide• Bidou and Gem assemblages• restricted back-arc or arc-rift basins• evidence of synvolcanic
alteration, exhalites, sulphideoccurrences (in-situ or clasts)
Volcanic-hosted massive sulphide• Bidou and Gem assemblages• restricted back-arc or arc-rift basins• evidence of synvolcanic
alteration, exhalites, sulphideoccurrences (in-situ or clasts)
SpinifexkomatiiteSpinifexkomatiite
CSIRO, 2004CSIRO, 2004
Komatiite Ni• Wallace and Garner assemblages• ultramafic (komatiitic) flow
complexes with interlayeredsulphidic sedimentary rocks
• no known occurrences
Komatiite Ni• Wallace and Garner assemblages• ultramafic (komatiitic) flow
complexes with interlayeredsulphidic sedimentary rocks
• no known occurrences
Sulphidic IFSulphidic IFKambalda/Raglan-typeKambalda/Raglan-type
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Rice Lake belt:ongoing explorationRice Lake belt:ongoing exploration
Central MBCentral MB
AngelinaBanksianAngelinaBanksian
English L.English L.
GoldridgeGoldridge
Red Rice L.Red Rice L.
Rio-SaxtonMike PowerPoundmakerJeep
Rio-SaxtonMike PowerPoundmakerJeep
SG1GabrielleGreenbeltOro Grande-Gunnar
SG1GabrielleGreenbeltOro Grande-Gunnar
Magmatic Ni-PGE
Orogenic gold
Magmatic Ni-PGE
Orogenic gold
Lesavage N.Moore L.Lesavage N.Moore L.
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MGS activities 2007:Geological context of lode-gold
occurrences in the Lily Lake area
MGS activities 2007:Geological context of lode-gold
occurrences in the Lily Lake area
Principal results:• Distinctive stratigraphic affiliation:
- quartz-greywacke turbidites- iron formation- polymictic conglomerate- mafic intrusive/extrusive
• Spatial association with zones ofstructural complexity
• Three styles of mineralization:- shear-hosted quartz veins- STWK / BX / wall-rock dissem.- sulphidized iron formation
• Analogous gold districts:- Beardmore-Geraldton, ON- Eleonore, QC- Meliadine trend, NU
Principal results:• Distinctive stratigraphic affiliation:
- quartz-greywacke turbidites- iron formation- polymictic conglomerate- mafic intrusive/extrusive
• Spatial association with zones ofstructural complexity
• Three styles of mineralization:- shear-hosted quartz veins- STWK / BX / wall-rock dissem.- sulphidized iron formation
• Analogous gold districts:- Beardmore-Geraldton, ON- Eleonore, QC- Meliadine trend, NU
** see Report GS-11 **R of A 2007
** see Report GS-11 **R of A 2007
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3096E shear vein’16-type’
3096E shear vein’16-type’
MGS activities 2007:Structural controls and timing
of vein emplacement
MGS activities 2007:Structural controls and timing
of vein emplacement
2902 breccia vein’38-type’
2902 breccia vein’38-type’
Unresolved questions:1) Relationship of the
38- and 16-type veins?2) Controls on vein
emplacement?3) Timing of vein-emplacement
relative to the regional deformations?
Unresolved questions:1) Relationship of the
38- and 16-type veins?2) Controls on vein
emplacement?3) Timing of vein-emplacement
relative to the regional deformations?
** see Poster T2 **Convention Floor** see Poster T2 **Convention Floor
38-type
38-type 16-type16-type
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ConclusionsConclusions
• ca. 300 million year history• ca. 300 million year history
• continental-arc / marginal oceanic-arc to back-arc / arc-rift settings
• continental-arc / marginal oceanic-arc to back-arc / arc-rift settings
• indications of significant potential formagmatic Ni-Cu-PGE, komatiite Ni, VHMS Cu-Pb-Zn(Au,Ag)
• indications of significant potential formagmatic Ni-Cu-PGE, komatiite Ni, VHMS Cu-Pb-Zn(Au,Ag)
• complex deformational history associated withca. 2.69 Ga continent-continent collision
• complex deformational history associated withca. 2.69 Ga continent-continent collision
• minimal systematic modern exploration• minimal systematic modern exploration
• north-verging subduction / accretion complex• north-verging subduction / accretion complex
• demonstrated potential for major orogenic lode-gold deposits• demonstrated potential for major orogenic lode-gold deposits
Rice Lake greenstone belt:Rice Lake greenstone belt:
A-shaft headframeRice Lake mineA-shaft headframeRice Lake mine
2998W vein“High-grade zone”2998W vein“High-grade zone”
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