K. HOLT 1, S. PERROUTY 2 , B. FRIEMAN 2 , L. GODIN 1

Kinematic analysis of the Manitou-Dinorwic deformation zone and its implications for mineral exploration in the western Wabigoon subprovince 2Mineral Exploration Research Centre (MERC), Harquail School of Earth Sciences, Goodman School of Mines, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada;

Located within the Archean western Wabigoon subprovince (WWS) in north-western Ontario (Fig. 1), the NE-trending Manitou-Dinorwic Deformation Zone (MDdz) hosts 95% of the historical gold production in the Dryden area (Manitou Gold Inc., 2010). The goal of this study is to document the structural development, alteration and kinematic history of the MDdz with the potential to help guide future exploration along similar deformation zones within the WWS.

Despite sharing a similar magmatic, sedimentary and tectonic evolution with the well-endowed Abitibi subprovince (Veillette et al., 2005), the Wabigoon subprovince is largely underexplored, structurally uncharacterized and assumed poorly endowed (Blackburn et al., 1991). Relative timing of orogenic gold mineralization compared to the structural evolution of both the Wabigoon and the Abitibi subprovinces may explain the disparity in gold endowment betweenthe two regions.

In order to better understand the relative timing of mineralization and deformation in the WWS,we investigated the MDdz at the Kenwest property (Manitou Gold Inc., 2010) where gold mineralization has been documented (see inset in Fig. 1A). To differentiate between regional scale deformation and MDdz-specific deformation, all localized structures will be denoted with a subscript M to indicate that the observation was made along the MDdz (e.g. D1M indicates the first deformation event observed along the MDdz).

INTRODUCTION

GEOLOGICAL SETTING & STUDY AREA

Figure 1. A) Geological map of the Dryden-Stormy area highlighting the regional deformation zones and the location of the western Wabigoon subprovince within the Superior Province (Frieman et al., 2018). Coordinatesare in NAD 1983, UTM15N. B) Reduced-to-pole total magnetic intensity over sun-shaded first vertical derivative magnetic map of the western Wabigoon subprovince. Note that red and pink correspond to magnetic highs, green to moderate values and blue to magnetic lows. The location of the outcrop is highlighted with a black point on both diagrams.

Figure 2. Map displaying lithological units, structural features and corresponding stereoplots with average orientations. Coordinates are in NAD 1983, UTM15N.

OBSERVATIONS & INTERPRETATIONS

Acknowledgments & References

Blackburn, C., Johns, G., Ayer, J., & Davis, D. (1991). Chapter 9 - Wabigoon Subprovince. In Williams, & Thurston, Geology of Ontario: Ontario Geological Survey - Special Volume 4 (pp. 303-381). Kenora: Ontario Geological Survey.Frieman, B., Perrouty, S., Montsion, R., Zammit, K., & Downie, D. (2018). Dryden-Stormy Area - Stratigraphic and Structural Characteristics of the Western Wabigoon Subprovince. Sudbury: Metal Earth - Mineral Exploration Research CentreManitou Gold Inc. . (2010). Kenwest Property: National Instrument 43-101 Compliant Technical Report. Toronto: WARDROP.Veillette, J., Paradis, S., & Buckle, J. (2005). Bedrock and surficial geology of the general area around Rouyn-Noranda, Quebec and Ontario. Ottawa: Geological Survey of Canada.

Financial support was provided by Canada First Research Excellence Fund, Queen’s Tectonics Research Laboratory (QTRL),and the Mineral Exploration Research Center (MERC) at Laurentian University. I am particularly grateful to Dr.S Perrouty, Dr. B. Frieman and Dr. L. Godin for your expertise and guidance. Data contributions from Kendra Zammit, David Downie and Rebecca Montsion are very much appreciated. Harquail School of Earth Sciences, Mineral Exploration Research Centre contribution MERC-ME-2019-110

1Queen’s Tectonics Research Laboratory (QTRL), Department of Geological Sciences and Geological Engineering, Queen’s University, 36 Union St W, Kingston, ON, K7L 2N8, Canada; 14kah11@queensu.ca

1) Four main rock units are observed at the Kenwest property: massive intermediate metavolcanic flows, pillowed to massive intermediate plagioclase-phyric metavolcanic flows, a quartz-feldspar porphyritic dike and quartz veins (Fig. 2).

2) Three generations of veins have been identified: quartz-rich between D1M and D2M, gold-hostingfracture-filling quartz-rich late to post-D2M and calcite-rich pre to early-D3M.

3) Three phases of deformation have been recognized on the outcrop: D1M - NEE striking isoclinal folding, D2M - NE striking transpressional sinistral shearing, D3M - late crenulation and faulting (Table 1).

4) Dominant chlorite-epidote metamorphic assemblages indicate that D1M, D2M and D3Mdeformation occurred at greenschist facies metamorphic conditions.

5) Hydrothermal alteration is syn-D2M and is characterized by extensive quartz veining associated with a sericite-calcite-ankerite-quartz-sulfide mineral assemblage (Fig. 4).

6) Gold mineralization along the Manitou-Dinorwic deformation zone is located within quartz veins and disseminated sulfide minerals that are spatially associated with felsic dikes within metavolcanic flows.

SUMMARY OF STRUCTURAL & PETROGRAPHIC OBSERVATIONS

Table 1. Summary of the structural development of the Manitou-Dinorwic deformation zone.

References

Figure 3. Macrostructures and kinematic indicators observed at the Kenwest outcrop unless otherwise stated. A) Overprinting of the S2M fabric over the S1M fabric. B) Sinistral C-S fabric in a volcaniclastic rock along Dinorwic Lake (Fig. 1A). C) S2M fabric sinistrally bent around a fracture-filling quartz vein on Highway 502, along strike of the MDdz (Fig. 1A). D) D3M crenulation cleavage. E) Late sinistral faulting of 2nd generation quartz veins.

Figure 4. Microstructures along the MDdz. A), B) Dextrally rotated pyrite(parallel to stretching lineation) in vertical plane. C), D) Dextral C-S fabric in quartz-feldspar-porphyritic dike (parallel to stretching lineation) invertical plane. E), F) Sinistrally rotated pyrite in horizontal plane. G), H) Sinistral C-S fabric in horizontal plane. I), J) Crenulation of S2M fabric by S3M fabric (parallel to stretching lineation).

A)

Seismic transect

Roads and trails

Waterbodies

Geological LinesContact - Inferred

Contact - Approximate

Deformation zone - Inferred

Deformation zone - Approximate

Geophysical trace

LithologiesDiabase dike

Unsubdivided porphyrytic intrusive units

Iron formation

Timiskaming-like sedimentary and volcanic units

Porcupine-like sedimentary units

Unsubdivided gneissic-plutonic units

Unsubdivided felsic intrusive units

Unsubdivided mafic intrusive units

Felsic volcanic units

Mafic to intermediate volcanic units

Regional deformation zone

LEGEND

0 4 8 12 162

Mosher Bay-Washeibemaga deformation

Mosher Bay-Washeibemaga deformation

Wabigoon Lake

Upper Manitou

Lake Stormy Lake

Wabigoon deformation zone

Man

itou-

Dino

rwic

def

orm

atio

n zo

ne

Man

itou-

Dino

rwic

def

orm

atio

n zo

ne

Wabigoon deformation zone

HWY 17

HWY 17

Wabigoon Lake

Upper Manitou

Lake Stormy Lake

Revellbatholith

Revellbatholith

BasketLake

batholith

BasketLake

batholith

AtikwabatholithAtikwa

batholith

TaylorLakeStock

TaylorLakeStock

Dinorwic Lake

Dinorwic Lake

519 000 mE 528 000 mE 537 000 mE 546 000 mE 555 000 mE

5 44

0 00

0 m

N5

450

000

mN

5 46

0 00

0 m

N5

470

000

mN

5 48

0 00

0 m

N5

490

000

mN

5 50

0 00

0 m

N5

510

000

mN

5 52

0 00

0 m

N

km

IMPLICATIONS FOR GOLD EXPLORATION IN THE WESTERN WABIGOON SUBPROVINCE

1) Gold mineralization on the Kenwest property occurred during the local D2M event, whichcorresponds to the regionl D3 event.

2) Gold mineralization within the WWS is associated with felsic dikes along NE-trending transpressional shear zones that have crosscut earlier E-W trending deformation zones and major isoclinal folds. During deformation, brittle fractures within these dikes likely acted as conduits for gold-bearing mesothermal fluids that have the potential to deposit mineralization in economic quantities within quartz-carbonate veins (e.g. 53 700 g/t on Kenwest property; Manitou Gold Inc, 2010).

3) This study proposes a new structural setting and timing for orogenic gold mineralization in the WWS, which is late relative to terrane accretion during regional amalgamation and localized along NE-trending high-strain corridors. Future exploration in the Superior Province could therefore consider similar NE-SW deformation zones to be potentially prospective for high-grade gold mineralization.

A B

A)

S1M: N021° / 72°S2M: N037° / 90°L2M: 72° → N027°

Faults: N043° / 90°Slickenlines: 79° → N037°

S3M: N263° / 47°

84

69

81

8982

8559

7765

8082

76

50

88

78

877252

8844

8238

46

77

65

8559

7949

8452

7044

8435

88

8562

2 m

Intermediate metavolcanic flow

Plagioclase-phyric intermediate metavolcanic flow

Plagioclase-phyric pillowed intermediate metavolcanic flow

Fe-carbonate altered plagioclase-phyric intermediate metavolcanic flow

Fe-carbonate altered quartz-feldspar porphyry dike

N

522070 mE

5476600 mN

First generation quartz veins

Thrust fault

Sinistral strike-slip fault

Foliation with lineation

Second generation quartz veins

Third generation quartz veins

Strike and dip of vertical bedding

Fig. 3A

Fig. 3D

Fig. 3E

Event Shortening Direction

Structure Veins Alteration

Series of intermediate metavolcanic

flows

N/A Primary: pillows,

vesicles, amygdules

None observed N/A

D1M NWW-SEE

1. Regional isoclinal folding,

axial planar foliation

None observed None observed

Intrusion of quartz-feldspar-porphyritic dike

N/A N/A 1st generation quartz rich (post QFP intrusion)

N/A

D2M NW-SE

Transpressional shear zone:

1. NW over SE thrusting

2. Late sinistral offset

3. QFP dike boudinaged along

strike

2nd generation quartz rich,

fracture filling, host gold

mineralization

Sericitic Iron-carbonate

Pyrite dissemination

D3M NE-SW 1. Crenulation of main D2 fabric 2. Late faulting

3rd generation calcite rich pre to

early D3 None observed

Study AreaStudy Area

HWY 502

B)

B)

C)

D) E)

A)

S1M

S2M

N

2 cm

S2M

D)

S3M

A B

4 cm

C D E

Fig. 3B

Fig. 3C

FOV: 4.7 mm, PPL

FOV: 4.7 mm, XPL

C D NW ↑ Up NW ↑ Up

FOV: 7.5 mm, PPL

FOV: 7.5 mm, XPL

E F N W E S

N W E S

FOV: 2.15 mm , PPL

FOV: 2.15 mm, XPL

G H

N W E S

N W E S

FOV: 13 mm, PPL

FOV: 13 mm, XPL

I J NW ↑ Up NW ↑ Up

FOV: 4.7 mm , PPL

FOV: 4.7 mm, XPL

A NW ↑ Up NW ↑ Up

Pyrite with Qtz-Chl-Calpressure shadows(dextral)

Pyrite with Qtz-Chl-Calpressure shadows(sinistral)

Dextral C-Sfabric

SinistralC-S fabric

S3M crenulation

B