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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
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.
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
Rice Lake belt: general geologyRice Lake belt: general geology
NORTH CARIBOUNORTH CARIBOU
UCHIUCHI
ENGLISH RIVERENGLISH RIVER
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
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
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
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(?)
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
San Antonio assemblage• quartz greywacke, quartzite,
conglomerate, turbiditicgreywacke
•
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
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
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
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.
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
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
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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