An appraisal of the potential for volcanic-hosted massive sulphide (VHMS) deposits in the Archean Rice Lake greenstone belt,

southeastern Manitoba.

An appraisal of the potential for volcanicAn appraisal of the potential for volcanic--hosted massive hosted massive sulphidesulphide (VHMS) deposits (VHMS) deposits in the in the ArcheanArchean Rice Lake greenstone belt, Rice Lake greenstone belt,

southeastern Manitoba.southeastern Manitoba.

Manitoba Mining & Minerals Convention 2005

Manitoba Mining & Minerals Convention 2005

Scott AndersonManitoba Geological SurveyScott AndersonScott Anderson

Manitoba Geological SurveyManitoba Geological Survey

C. Chamale, U of M summer student

OutlineOutline

VHMS deposits:• exploration criteria

VHMS deposits:• exploration criteria

Rice Lake greenstone belt:• regional setting• geology and stratigraphy• geochemistry• paleotectonic setting

Rice Lake greenstone belt:• regional setting• geology and stratigraphy• geochemistry• paleotectonic setting

VHMS potential:• Rice Lake area• Gem Lake area

VHMS potential:• Rice Lake area• Gem Lake area

A. Carlson, U of M summer student

VHMS deposits:exploration criteriaVHMS deposits:

exploration criteria

(Franklin, 1993)

• VHMS-style mineral occurrences• VHMS-style mineral occurrences

Alan Galley, GSC

Regional scale:Regional scale:

Local scale:Local scale:

• proximal footwall alteration ‘pipes’;Mg- and Fe-chlorite, sericite-quartz

• proximal footwall alteration ‘pipes’;Mg- and Fe-chlorite, sericite-quartz

• Intraoceanic- or continental-arcs• Extensional geodynamic settings (arc-rift or

mature back-arc spreading centre)• bimodal volcanic succession; submarine

depositional environment

• Intraoceanic- or continental-arcs• Extensional geodynamic settings (arc-rift or

mature back-arc spreading centre)• bimodal volcanic succession; submarine

depositional environment• subvolcanic intrusions (heat source)• subvolcanic intrusions (heat source)• high-T rhyolitic volcanism;

proximal felsic flow-complexes• high-T rhyolitic volcanism;

proximal felsic flow-complexes• regional semi-concordant alteration

zones; silica-epidote• regional semi-concordant alteration

zones; silica-epidote

• synvolcanic faults (discordant alteration,facies changes, dike swarms)

• synvolcanic faults (discordant alteration,facies changes, dike swarms)

• laterally extensive exhalite horizons• laterally extensive exhalite horizons

Manito

baOntar

io

Wabigoon

Uchi

Winnipeg R.

Berens River

Oxford-Stull

LakeWinnipeg

Northern Superior

English R.

Quetico

WawaLake

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

Manito

baOntar

io

Wabigoon

Uchi

Winnipeg R.

Berens River

Oxford-Stull

LakeWinnipeg

Northern Superior

English R.

Quetico

WawaLake

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

Western SuperiorProvince

• Prolific host toOLG deposits

• Prolific host toOLG deposits

• Few known VHMSoccurrences

• Few known VHMSoccurrences

NCTNCT

Rice Lake beltRice Lake belt

Red Lake beltRed Lake belt

VHMS deposit /district

Rice Lake greenstone beltRice Lake greenstone belt

Central RLB:geology

Central RLB:geology

* PMAP2005-1

F6 foldF6 fold

D2 thrustD2 thrust

Angular unconformity (D1)Angular unconformity (D1)

F3 foldsF3 folds

D4-D5 high-strain zonesD4-D5 high-strain zones

SAA

RRP

WSZ

Southeast RLB:geology

Southeast RLB:geology

BLA (D3)BLA (D3)

BL-WGSZ(D4-D5)

BL-WGSZ(D4-D5)

RRPRRP

BidouBidou

GemGem

EdmundsEdmunds

GarnerGarner

F6 foldF6 fold

Rice Lake belt: Neoarchean stratigraphyRice Lake belt: Neoarchean stratigraphy

Lower Bidou:ca. 2.73 Ga ocean-floor basalt

Lower Bidou:ca. 2.73 Ga ocean-floor basalt

Pillowed basalt flowHalfway LakePillowed basalt flowHalfway Lake

Bedded greywacke and chertin pillowed basaltHalfway Lake

Bedded greywacke and chertin pillowed basaltHalfway Lake

* Unpublished data from Bailes (1998) and Anderson (2004-2005)* Unpublished data from Bailes (1998) and Anderson (2004-2005)

ENd 2.73 Ga 0.48 & 2.13 (Tomlinson et al., unpub.)ENd 2.73 Ga 0.48 & 2.13 (Tomlinson et al., unpub.)

ENd 2.73 Ga 1.4 (this study)ENd 2.73 Ga 1.4 (this study)

Upper Bidou:ca. 2.73-2.72 Ga arc dacite-andesite

Upper Bidou:ca. 2.73-2.72 Ga arc dacite-andesite

Andesite-dacite brecciaRice LakeAndesite-dacite brecciaRice Lake

Dacite brecciaRice LakeDacite brecciaRice Lake

*Unpublished data from Bailes (1998), Corkery (1995, 1999) and Anderson (2002-2005)*Unpublished data from Bailes (1998), Corkery (1995, 1999) and Anderson (2002-2005)

ENd 0.3 & 1.1

TDM 3.03 & 2.94 Ga

ENd 0.3 & 1.1

TDM 3.03 & 2.94 Ga

Upper Bidou:ca. 2.73-2.72 Ga arc basalt-andesite

Upper Bidou:ca. 2.73-2.72 Ga arc basalt-andesite

Pillowed basalt flowRice LakePillowed basalt flowRice Lake

Contorted magmatic layeringIn leucogabbro (SAM unit)Rice Lake

Contorted magmatic layeringIn leucogabbro (SAM unit)Rice Lake

ENd 1.2

TDM 2.91 Ga

ENd 1.2

TDM 2.91 Ga

* Unpublished data from Bailes (1998) and Anderson (2004-2005)* Unpublished data from Bailes (1998) and Anderson (2004-2005)

Gem assemblage:ca. 2.72 Ga arc-rift rhyolite

Gem assemblage:ca. 2.72 Ga arc-rift rhyolite

Altered rhyolite brecciaAltered rhyolite breccia

Flow-banded rhyoliteFlow-banded rhyolite

ENd 0.3 & 0.9

TDM 3.10 & 2.99 Ga

ENd 0.3 & 0.9

TDM 3.10 & 2.99 Ga

*Unpublished data from Corkery (1995, 1999) and Anderson (2002-2005)*Unpublished data from Corkery (1995, 1999) and Anderson (2002-2005)

Gem assemblage:ca. 2.72 Ga arc-rift basalt

Gem assemblage:ca. 2.72 Ga arc-rift basalt

Pillowed basalt flowPillowed basalt flow

Mafic breccia withamygdaloidal basalt clastsMafic breccia withamygdaloidal basalt clasts

ENd - 0.4 (at 2.72 Ga)ENd - 0.4 (at 2.72 Ga)

*Unpublished data from Corkery (1995, 1999) and Anderson (2002-2005)*Unpublished data from Corkery (1995, 1999) and Anderson (2002-2005)

Rice Lake belt:paleotectonic setting

Rice Lake belt:paleotectonic setting

ca. 2.73 Gacontinental-arc / marginal-arcca. 2.73 Gacontinental-arc / marginal-arc

continental crustback-arc crustmantlewedge

back-arc ridge

riftedcontinental

arc

trench

slab

back-arcbasin

ca. 2.73-2.72 Gaarc-extension

back-arc basin / arc-rift

ca. 2.73-2.72 Gaarc-extension

back-arc basin / arc-rift

Bimodal VHMS systemsBimodal VHMS systems

Central RLB:geology

Central RLB:geology

Back-arcBack-arcArcArc

ArcArc

Dacite brecciaDacite breccia

Pillowed basaltPillowed basalt

Greywacke-mudstoneturbidites

Greywacke-mudstoneturbidites

Water-lain felsic tuffWater-lain felsic tuff

Heterolithic debris flowHeterolithic debris flow

Dacite lapilli tuff cut bygabbro dikesDacite lapilli tuff cut bygabbro dikes

Rainy Lake Road section:stratigraphyRainy Lake Road section:stratigraphy

500 m

Ross River Pluton Bt-Hb quartz diorite

Calcalkaline-arc Dacite tuff breccia, breccia, tuff Heterolithic conglomerate, sandstone Abundant gabbro dikes/sills

Epiclastic rocks Greywacke-mudstone turbidites Heterolithic debris flows Gabbro sills Pillowed basalt flows Water-lain felsic tuff

Tholeiitic back-arc Massive and pillowed basalt flows Gabbro sills Flow-breccias

Arc extensionSubsidence

Arc / back-arc trans.

Semiconcordantchlorite alterationSemiconcordantchlorite alteration

Solid-sulphide (po-cpy)clasts in debris flow

Solid-sulphide (po-cpy)clasts in debris flow

• Arc extension• Basin subsidence• Arc / back-arc transition

• Arc extension• Basin subsidence• Arc / back-arc transition

ca. 2730 Ma

ca. 2728 Ma

Debris flow withsulphide clasts

Chlorite alteration

500 m

Ross River Plutonsubvolcanic intrusion (heat source)

Rainy Lake Road section:VHMS potential

Rainy Lake Road section:VHMS potential

Southeast RLB:geology

Southeast RLB:geology

Back-arcBack-arc

ArcArc

Arc-riftArc-rift

Arc-riftArc-rift

ArcArc

* Compiled from Stockwell(1945), Weber (1971),Seneshen and Owens (1985),and Anderson (2003)

* Compiled from Stockwell(1945), Weber (1971),Seneshen and Owens (1985),and Anderson (2003)

Gem assemblage VHMS potential:rhyolitic volcanic unit

Gem assemblage VHMS potential:rhyolitic volcanic unit

Pillowed felsic flowPillowed felsic flow Collapsed pumice lapilliin QFP rhyolite brecciaCollapsed pumice lapilliin QFP rhyolite breccia

Collapsed pumice lapilliIn rhyolite tuffCollapsed pumice lapilliIn rhyolite tuff

Flow-banded rhyolitebrecciaFlow-banded rhyolitebreccia

Rhyolite brecciaRhyolite breccia

Flow-banded rhyoliteFlow-banded rhyolite

• flow complexes• proximal volcaniclastic• pumeceous pyroclastic

= subaerial and subaqueous volcanism

• flow complexes• proximal volcaniclastic• pumeceous pyroclastic

= subaerial and subaqueous volcanism

Gem assemblage VHMS potential:FII - FIII rhyoliteGem assemblage VHMS potential:FII - FIII rhyolite

500Kilometres

South Bay

Mattabi

Geco

Kidd CreekLouvicort

Detour

Noranda

Mattagami

McFauld’sLake

Horne

Superior ProvinceVHMS deposits

Superior ProvinceVHMS deposits

Gem assemblage VHMS potential:hydrothermal activity

Gem assemblage VHMS potential:hydrothermal activity

Rhyolitic sandstone with black chert interbedsRhyolitic sandstone with black chert interbeds

Sericite alteration in rhyoliticsandstoneSericite alteration in rhyoliticsandstone

‘Exhalative’ horizons?‘Exhalative’ horizons?

SyngeneticalterationSyngeneticalteration

Sulphide occurrencesSulphide occurrencesChlorite-garnet alterationChlorite-garnet alteration

Gossanous qtz-ser-pyalteration in rhyolite brecciaGossanous qtz-ser-pyalteration in rhyolite breccia

Altered (ser-py) clasts inheterolithic conglomerateAltered (ser-py) clasts inheterolithic conglomerate

Pyritic clastPyritic clast

Near-solid pyrite lensNear-solid pyrite lens

ConclusionsConclusions

• continental-arc / marginal oceanic-arc to back-arc setting• continental-arc / marginal oceanic-arc to back-arc setting

• extensional geodynamic settings (arc-rift)• extensional geodynamic settings (arc-rift)

• hydrothermal activity• hydrothermal activity

• subvolcanic intrusions• subvolcanic intrusions

• base-metal sulphide occurrences• base-metal sulphide occurrences

• bimodal submarine volcanism• bimodal submarine volcanism

• FII – FIII rhyolitic flow-complexes• FII – FIII rhyolitic flow-complexes

Favourable indications of VHMS potential:Favourable indications of VHMS potential:

P. Kremer, U of M summer student