Download Preliminary Investigation of the Thermotectonic History of the Central

Preliminary Investigation of the Thermotectonic History of the
Central Rottenstone Domain, Hickson and Rottenstone Lakes,
Saskatchewan
Kate MacLachlan
MacLachlan, K. (2003): Preliminary investigation of the thermotectonic history of the central Rottenstone Domain, Hickson and
Rottenstone lakes, Saskatchewan; in Summary of Investigations 2003, Volume 2, Saskatchewan Geological Survey, Sask.
Industry Resources, Misc. Rep. 2003-4.2, CD-ROM, Paper A-5, 20p.
Abstract
This paper reports results of 1:20 000 scale bedrock mapping in two areas in the central Rottenstone Domain of
northern Saskatchewan. In the Hickson Lake area, on the eastern edge of the Rottenstone Domain, two distinct
packages of metamorphosed supracrustal rocks were recognized on the east side of Hickson Lake. The first consists
of massive to thinly bedded psammitic to pelitic rocks and the second includes psammitic to pelitic rocks, quartz
arenites and calc-silicate rocks, as well as minor amphibolite and large metagabbro dykes. These rocks were
metamorphosed to lower to middle amphibolite facies grade during an early phase of deformation that produced a
bedding-parallel foliation (S1). The second phase of deformation occurred under similar metamorphic conditions
and involved tight to isoclinal upright folding of bedding and S1. These F2 folds are doubly plunging and have
steeply east-southeast-dipping axial planes. Foliated and metamorphosed tremolite/actinolite-biotite ultramafic
dykes post-date S1, but are folded by F2 folds. Biotite granodiorite and monzogranite of the Hickson Lake pluton
intruded the supracrustal rocks and post-dated F2 folds. Abundant granitic to syenitic pegmatite was intruded
throughout the area after D2. Migmatitic tonalite on the west side of Hickson Lake is separated from the
supracrustal rocks by the Hickson Lake pluton. Folding of the main fabric in this tonalite migmatite is thought to
post-date folding in the supracrustal rocks and is thus designated F3. The final phase of folding (F4) was only
documented in the supracrustal rocks and is characterized by asymmetric folds and two conjugate crenulation
cleavages with steeply dipping, east-southeast- and north-northeast-striking orientations, and post-dated pegmatite
intrusion.
The second map area, around Rottenstone Lake in the central Rottenstone Domain, comprises rocks of the ‘tonalitemigmatite complex’. There are five units that contain a large proportion (>50%) of well-preserved supracrustal
rocks and early granitoid sheets. A strong foliation oriented parallel to compositional layering in the
metasedimentary rocks and the early granitoid sheets is designated Smain. The supracrustal rocks include pelitic to
psammopelitic migmatites with in situ leucosome, biotite-hornblende-plagioclase melanocratic
metasedimentary/metavolcanic rocks, quartzite, calc-silicate, biotite psammite, and amphibolite. Granitoid sheets
that pre-date Smain are predominantly biotite ± hornblende granodiorite to monzogranite, but also include
hornblende diorite, tonalite, and quartz monzonite. A large part of the mapped area is underlain by white to pink
tonalite to monzogranite that is massive to weakly foliated, contains abundant metasedimentary xenoliths and
schlieren, and post dates Smain in the supracrustal rocks. The Smain foliation is folded into tight to isoclinal, upright
to recumbent, doubly plunging folds with northeast-striking axial planes. These folds have been refolded by upright,
open, shallowly doubly plunging folds, also with northeast-striking axial planes. The map pattern indicates that
although the late granitoids post-date the main fabric, they have been affected by both later phases of folding.
Ultramafic intrusions that host the Rottenstone Deposit and the Tremblay-Olsen showing occur within
metasedimentary rocks and in gently plunging hinge zones of the late, upright, open folds.
The relative and absolute timing of deformation and metamorphism in the two map areas is uncertain, but is being
tested with U/Pb geochronology.
Keywords: thermotectonic, Rottenstone Lake, Hickson Lake, migmatite, deformation, metamorphism, ultramafic
rocks.
1. Introduction
The Rottenstone Domain is a predominantly sedimentary-derived migmatite terrane (Gilboy, 1982) within the
Paleoproterozoic Trans-Hudson Orogen. It occurs between the oceanic La Ronge volcanic arc to the southeast and
the Wathaman continental arc batholith to the northwest (Figure 1). Rocks of the Rottenstone Domain have
undergone upper amphibolite facies metamorphism and polyphase deformation. The tectonic setting and age of
deposition of the sedimentary protoliths, their subsequent thermotectonic history, and their relationship to the
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Figure 1 - Simplified regional geology of the central Rottenstone and adjacent domains in northern Saskatchewan. Inset
shows domains of the Precambrian Shield of northern Saskatchewan and the location of the regional geology map. Shear
zones are indicated. The locations of Figures 2 and 7 are indicated by boxes on the regional geology map.
evolution of the Trans-Hudson Orogen are poorly constrained (Johnston and Thomas, 1984; Lewry and Collerson,
1990; Corrigan et al., 2001).
To the northeast of this study area, mapping and integrated geoscience studies on Reindeer Lake, done as part of the
La Ronge-Lynn Lake Bridge Project (Harper, 1996; Corrigan et al., 1997; Maxeiner, 1997; Maxeiner et al., 2001)
led to the recognition of several distinct lithotectonic assemblages of different age and origin. One of these, the ca.
1.865 to 1.860 Ga Milton Island Assemblage, comprises migmatitic metasedimentary gneisses and has stratigraphic
continuity across the previously defined boundary between the La Ronge and Rottenstone domains. This has led to
questioning of that boundary and the tectonostratigraphic relationship between the La Ronge and Rottenstone
domains farther to the southwest.
The Rottenstone Domain derives its name from a lake named for the rubbly ultramafic rock on its east shore. This
ultramafic intrusion, initially staked as the Hall showing, hosted a small but rich magmatic Ni-PGE deposit, which
became the Rottenstone Mine in the late 1960s. The age, nature, tectonic affinity, and structural geometry of the
intrusion are not known, but the metal content of the deposit suggests that it was related to a much larger magmatic
body (L. Hulbert, pers. comm., 2003) that to date remains elusive.
There are three principle objectives of this project: 1) to gain a better understanding of the lithologies,
tectonostratigraphy, depositional setting, and provenance of the metasedimentary rocks in the central Rottenstone
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Domain; 2) to characterize the timing and nature of the regional thermotectonic history; and 3) to improve
understanding of the origin, tectonic setting, and structural geometry of the ultramafic intrusion that hosts the
Rottenstone Ni-PGE deposit. The approach taken to solving these problems will be an integrated, multi-disciplinary,
multi-institutional project based on a 1:20 000 scale mapping transect through the central Rottenstone Domain, from
Hickson Lake through Rottenstone Lake to McPherson Lake (Figure 1). In addition, petrological, geochemical,
isotopic, and geochronological studies in collaboration with the Geological Survey of Canada, Memorial University
of Newfoundland, and University of Regina will be undertaken. The initial phase of mapping was undertaken
during the summer of 2003 and a summary of the results is presented here. It focused on two separate areas, one on
the eastern margin of the transect, in the Hickson Lake area and the other in the immediate vicinity of the
Rottenstone mine at Rottenstone Lake (Figure 1).
2. Previous Work
The first prospecting around the Rottenstone Lake Ni-Cu-PGE deposit was carried out by Consolidated Mining and
Smelting Company of Canada in 1928 and 1929 (Gilboy 1982). In 1946, the deposit was described in detail by
Mawdsley. Various companies have explored the area since then. From 1965 to1968, Rottenstone Mining Ltd.
recovered 28,000 tons of ore from an open pit in the Rottenstone deposit (SIR assessment report 74A-075W-0033).
Claude Resources Inc. staked the area around the mine in 1983 and optioned it to INCO in 1990. INCO dropped the
option in 1992, but Claude Resources continued to maintain assessment requirements until 1998. In 1998, a large
area (138 sq. miles) surrounding the Rottenstone mine was acquired by Uravan Minerals Inc. of Calgary, who
subsequently completed a multiphase exploration program that included an airborne geophysical survey, a
biogeochemical survey, diamond drilling, and ground geophysics (e.g., SIR assessment report 74A-07-0037 and
-2000).
The earliest geological mapping, published at 1 inch to four miles (1:253,440), was undertaken by McMurchy
(1938a, 1938b). The area was most recently mapped at 1:100 000 scale by Gilboy (1982). Contiguous rock units to
the east and north (Deception Lake) of the present study area were mapped by Harper (1986, 1990). The structure,
geochronology, and geochemistry of the ‘tonalite-migmatite complex’ was the subject of an M.Sc. thesis by Chris
Coolican (2001) at University of Saskatchewan and a LITHOPROBE study in the Davin Lake area by Clarke et al.
(in press).
3. Regional Geology
The Rottenstone Domain is part of the Reindeer Zone (Stauffer, 1984), which constitutes the internides of the
Trans-Hudson Orogen (THO). The name ‘Rottenstone Domain’ was first used by Ray (1974), and included rock
units of both the later named Wathaman Batholith (Gilboy, 1975; Lewry, 1975, 1976; Ray, 1975; Stauffer et al.,
1976; Ray and Wanless, 1980; Lewry et al., 1981; Fumerton et al., 1984) and the ‘tonalite-migmatite complex’
(Lewry et al., 1981). Recognition of the Wathaman Batholith as a continental arc plutonic complex (Lewry et al.,
1981; Fumerton et al., 1984; Stauffer, 1984) caused it to be excluded from the Rottenstone Domain, leaving the
‘tonalite migmatite complex’ as the sole constituent. Recent reclassification of the Precambrian domains in
Saskatchewan, by the Saskatchewan Geological Survey (2003), included low-grade metasedimentary rocks of the
Crew Lake Belt (formerly part of the La Ronge Domain) as part of the Rottenstone Domain (Figure 1).
On Reindeer Lake, several lithotectonic assemblages have been distinguished within the Rottenstone Domain. The
Clements Island Belt near the margin of the Wathaman Batholith is predominantly mafic metavolcanic and
volcaniclastic rocks; an interbedded rhyolite dated at 1905 +17/-5 Ma (Corrigan et al., 2001), suggests a temporal
link with components of the Lynn Lake belt (Baldwin et al., 1987). The Crowe Island Complex (Corrigan et al.
1998) comprises banded tonalite-granodiorite-granite gneiss, the tonalitic and granitic components of which have
been dated at 1891 ±3 Ma and 1884 +5/-3 Ma, respectively (Corrigan et al., 2001). This complex is interpreted to be
the plutonic root of the La Ronge volcanic arc (Corrigan et al., 2001). The Milton Island Assemblage (Sibbald,
1977; Corrigan et al., 1998; Maxeiner, 1999; Williamson et al., 2000) is composed of migmatized psammopelitic
rocks containing detrital zircon populations ranging in age from 2.83 to 1.86 Ga (Ansdell et al., 1999) and
interpreted as a forearc or accretionary prism formed on the north side of the La Ronge arc (Corrigan et al., 2001).
Peak metamorphism in the Milton Island Assemblage is interpreted to have occurred at ca. 1.795 to 1.794 Ga during
terminal collision in the Trans Hudson Orogen (Ansdell et al., 1999; Corrigan et al., 2001). The Park Island
Assemblage is a fluvial to littoral siliciclastic package that sits structurally and possibly stratigraphically, above the
Milton Island Assemblage (Corrigan et al., 1998). It comprises polymictic conglomerate conformably overlain by
pink arkose with laminae and cross beds (Corrigan et al., 1998). Although the Park Island assemblage has some
characteristics similar to the circa 1.84 Ga McLennan/Sickle groups south of the La Ronge Domain, it is intruded by
the 1.86 Ga Wathaman Batholith (Corrigan et al., 2001) and must therefore be older than the McLennan/Sickle
groups (Corrigan et al., 1998).
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4. Hickson Lake Area Lake
The Hickson Lake area represents the easternmost part of this mapping transect. Metasedimentary rocks on the
eastern side of Hickson Lake (Figure 2) were formerly included in the Crew Lake Belt of the La Ronge Domain
(Gilboy, 1982), but have recently been reassigned to the Rottenstone Domain (Saskatchewan Geological Survey,
2003). This area was chosen as a starting point for this study because the middle amphibolite facies metamorphic
grade here is not as high as in the upper amphibolite migmatites farther west.
In the summer of 2002, much of the area southeast of Hickson Lake was burned in a large forest fire. The
consequent increase in amount and quality of exposure, combined with the more detailed scale of mapping, has
facilitated a more detailed subdivision of the rock units and a better understanding of the structural and
metamorphic history, as described below and shown in Figure 2.
a) Description of Rock Types
Supracrustal Rocks
Unit 1: Psammitic to Pelitic Metasedimentary Rocks
This unit is characterized by psammite, psammopelite, and iron-rich pelite interbedded in varying proportions. Most
of the unit is composed of thinly bedded (2 to 30 cm) psammite to psammopelite (Figure 3A). In part, psammite is
interbedded with thin bedded to laminated (<1 to 2 cm) iron-rich pelite (Figure 3B). The latter is locally up to
several meters thick with isolated psammite to psammopelite beds at 30 to 50 cm intervals. Gradual changes in
composition from a biotite-poor base to a more biotite-rich top within some beds is interpreted to reflect graded
bedding (Figure 3B). Thus, despite a significant degree of deformation and transposition, the layering in these rocks
is considered to be bedding. These rocks are commonly graphite-bearing (Gilboy, 1982) and have been
metamorphosed to middle amphibolite facies grade. In the psammites, the mineral assemblage is quartz-plagioclasebiotite-K-feldspar ± muscovite with rare garnet. This assemblage persists through psammopelitic and pelitic
compositions, but with an increase in biotite and muscovite. Iron-rich pelitic units locally contain small (<5 mm),
fine-grained polymineralic faserkiesel that comprise biotite-muscovite-sillimanite-quartz. Small lenses of granitoid
material with biotite selvedges occur locally adjacent to large quartz veins. This is interpreted as localized in situ,
melt-derived neosome resulting from the addition of hydrous fluids during quartz vein formation.
Unit 2: Mixed Metamorphosed Supracrustal Rocks
This unit is much more heterogeneous than Unit 1. Interbedded with psammopelitic rocks similar to those of Unit 1
are: 1) thin- to thick-bedded (5 to 50 cm) quartzite (Figure 3C) composed of >80% quartz plus muscovite and
biotite, commonly with quartz pebble lags; 2) quartz pebble metaconglomerates with either a quartz-rich, gritty
matrix or a calc-silicate matrix; 3) compositionally layered amphibolite comprising varying amounts of hornblende
and plagioclase, locally with minor garnet, biotite and quartz; and 4) thinly layered calc-silicate rock, commonly
associated with amphibolite and quartzite (Figure 3D). The calc-silicate layers comprise quartz, clinopyroxene, and
garnet in varying proportions. Graded bedding (Figure 3C), quartz pebble lags, and quartz pebble conglomerate
lenses and layers indicate that the primary bedding is preserved despite significant transposition.
Hickson Lake Pluton
Unit 3: Biotite Granodiorite
Biotite granodiorite intruded the metasedimentary units described above and post-dated the metamorphic fabric
within them. It is white weathering, leucocratic (5 to 8% biotite), homogeneous, fine grained, equigranular and
commonly contains very fine-grained, subrounded, biotite-rich inclusions (Figure 4A) interpreted as relict cognate
microdiorite inclusions. This unit commonly has a weak to moderate foliation defined by aligned biotite and is part
of the Hickson Lake pluton mapped by Gilboy (1982). The granodiorite is predominantly in the eastern part of the
pluton (Figure 2), and also as screens in the younger phases in the centre of the pluton.
Unit 4: Heterogeneous Biotite Monzogranite
This unit predominates at the centre of the Hickson Lake pluton. It is generally buff to pale pink weathering and
heterogeneous in both composition and texture. It ranges from fine to coarse grained, equigranular to K-feldspar
porphyritic and commonly contains biotite ± muscovite monzogranite to syenogranite pegmatite phases that have
both gradational and sharp contacts with the granite. This granite ranges in composition from monzogranite to
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Figure 2 - A) Simplified geological map of the Hickson Lake area.
B) Contoured lower hemisphere equal area stereonet plot of F3 fold axes from within the tonalite unit on the west side of
Hickson Lake.
C) Lower hemisphere equal area stereonet plot of poles to S4 crenulation cleavage and S4 axial planes measured in the
metasedimentary rocks on the east side of Hickson Lake.
D) Lower hemisphere equal area stereonet plot of contoured poles to bedding (and S1 foliation) and non-contoured poles to
the S2 foliation, measured in the metasedimentary rocks on the east side of Hickson Lake.
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Figure 3 - Field photographs of metasedimentary rocks from the east side of Hickson Lake: A) interbedded psammite and
psammopelite from the Unit 1 psammopelites; hammer is 32 cm long; B) interbedded psammite, psammopelite, and iron-rich
pelite from the Unit 1 psammopelite unit; note the well-developed S4 crenulation cleavage at a high angle to bedding in the
more pelitic layers; pencil is 15 cm long; C) quartzite interbedded with psammite to psammopelite from the Unit 2 mixed
supracrustal rocks; note graded bedding, arrows show tops.; and D) interbedded amphibolite (Am), calc-silicate (Cs), and
quartzite (Qz) from the Unit 2 mixed supracrustal rocks.
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granodiorite and from biotite-rich (15 to 20%), to more
leucocratic compositions (<10% biotite). In general,
contacts between the various compositional and textural
phases are gradational, although screens of foliated
biotite-granodiorite (Unit 3) typically have sharp contacts
with the monzogranite that intrudes them. The biotite
monzogranite is generally massive, but locally a weak
foliation is developed.
Units 5 and 6: K-feldspar Porphyritic Biotite
Monzogranite
Distinct bodies of this unit occur in the centre of the
Hickson Lake pluton. The larger body (Unit 5), at the
south end of the map area, is pale pink to buff
weathering, ranges from fine to medium grained and
contains 5 to 10% biotite. The contact with the nonporphyritic biotite monzogranite to granodiorite (Unit 4)
was not observed and may be gradational. A pinkweathering, massive, homogeneous, coarse-grained,
leucocratic (<5% biotite) and strongly porphyritic body
(Unit 6, Figure 4B) has sharp contacts with the biotite
monzogranite (Unit 4, Figure 5B). In three dimensions
this unit is sheet like, dips steeply northeast (60 to 70°) at
its northwestern end, and is more gently dipping (30 to
40°) and gently folded (Figure 4C) toward the southeast.
Other Intrusive Rocks
Unit 7: Leucotonalite
This unit, on the west shore of Hickson Lake, is both
texturally and compositionally heterogeneous. It is white
weathering and ranges from fine-grained, equigranular,
biotite poor (<5%) leucotonalite, to medium- to coarsegrained, locally plagioclase megacrystic, biotite-rich
granodiorite. It commonly contains abundant large
screens of supracrustal rocks up to 10 m wide, associated
with biotite-rich schlieren that are also interpreted to be
of supracrustal origin. This unit is massive to weakly
foliated and post-dates the main fabric preserved in the
metasedimentary xenoliths. Gilboy (1982) included Unit
7 in his ‘migmatitic gneiss’ unit, an interpretation
compatible with observations made in this study.
Unit 8: Pegmatite
Pegmatite dykes several centimeters to many meters in
width are common and range in composition from
monzogranite to syenogranite. They typically contain
both biotite and muscovite, although biotite predominates
where they intrude biotite-rich supracrustal rocks,
whereas muscovite predominates where they intrude
pelitic rocks. These pegmatites commonly contain very
large tabular, euhedral, pink, K-feldspar crystals. The
pegmatite bodies cut the metamorphic fabric in the
supracrustal rocks.
Saskatchewan Geological Survey
Figure 4 - Field photographs of intrusive units from the
Hickson Lake pluton: A) foliated biotite granodiorite (Unit
3) with microdiorite enclaves (at arrows), hammer is 32 cm
long; B) Unit 4 medium-grained, equigranular, massive
biotite monzogranite (i) cut by Unit 6 coarse-grained Kfeldspar porphyritic biotite monzogranite (ii), pencil is 15 cm
long; and C) gently dipping, folded sheet of Unit 6 coarsegrained, K-feldspar porphyritic granite (ii) within biotite
monzogranite (i), folded contact shown with dotted line.
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Dykes
Leucotonalite dykes were only observed within the metasedimentary units. They are fine grained, weakly to
moderately foliated and contain muscovite (5 to 10%) ± minor biotite. These dykes are commonly less than 50 cm
wide and cut the main metamorphic fabric in the metasedimentary rocks.
Plagioclase porphyritic intermediate dykes occur only within the supracrustal rocks. They are fine grained, sparsely
to moderately plagioclase porphyritic (3 to 5% phenocrysts, 2 to 6 mm), biotite bearing, light grey to light brown
weathering and weakly to moderately foliated. They range from tens of centimeters to several meters wide and cut
bedding at a slight angle.
Figure 5 - Field photographs illustrating the relative ages of intrusive rocks, deformation, and metamorphism: A) foliated
and metamorphosed mafic/ultramafic dyke within psammopelitic metasedimentary rocks, folded by F2 fold, hammer is 32 cm
long; B) close-up view of the same dyke showing grey reaction halo in metasedimentary rocks and an S4 crenulation cleavage
that extends from the pelitic metasedimentary rock into the biotite rich margin of the dyke; C) F2 folds in thinly layered
psammite, cut by biotite granodiorite, Brunton compass parallel to fold axes is 10 cm wide; and D) line drawing of the
photograph in C, at same scale and in same orientation.
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The ultramafic dykes are brownish green weathering, schistose, and predominantly composed of tremolite/actinolite
and biotite. They cut the metamorphic fabric in the metasedimentary rocks but have a strong foliation roughly
parallel to the dyke margins. These dykes are relatively narrow and discontinuous with distinct grey reaction halos
in the surrounding metasedimentary rocks and a general increase in biotite content and grain size in the dyke
margins (Figures 5A and 5B).
Several narrow (<1 m wide) metagabbro dykes were
observed in the Unit 1 psammopelitic rocks, but they
are much more common and wider (up to 75 m) in the
Unit 2 mixed supracrustal rocks. They comprise biotite,
hornblende, and plagioclase and range from fine
grained to locally pegmatitic. They are variably foliated
and contain abundant, commonly anastomosing,
clinopyroxene-bearing quartzofeldspathic veins that
have also been deformed.
5. Structural Geology
Three phases of deformation (D1, D2, and D4) have
been recognized east of the Hickson Lake pluton. A
fabric in the migmatites west of Hickson Lake (S3) is
thought to pre-date the final phase of deformation on
the east side of the lake (D4), although this has not been
proven. East of Hickson Lake the first generation
planar fabric (S1) is a bedding-parallel schistosity in
pelitic to semipelitic beds and a weak schistosity or
spaced cleavage in psammitic and quartz-rich beds,
defined by biotite ± muscovite. This corresponds to the
first tectonic fabric recorded by Gilboy (1982).
Wherever bedding can be recognized, there is a
bedding-parallel foliation, although in some places only
the foliation can be recognized. Abundant tiny quartz
veins parallel to bedding are also common. Bedding
and S1 generally strike north-northeast and dip steeply
(Figure 2D). No folding related to this fabric was
observed.
The second phase of deformation involved tight to
isoclinal, upright folding (F2) of bedding and the S1
foliation (Figure 6A). The F2 folds are north-northeasttrending and a steeply southeast-dipping axial planar
cleavage (S2) is developed locally (Figure 2D).
Abundant F2 folds were observed at an outcrop scale,
but could not be distinguished at the map scale. Areas
with ubiquitous W-folds, however, are thought to be
the hinge zones of larger scale folds. In these hinge
zones, an axial planar S2 fabric is locally defined by
leucosome veins and/or a spaced cleavage in pelitic to
semipelitic units. In areas of asymmetric F2 folds, an
incipient S2 schistosity and/or leucosome veins occur
along the long limbs of the folds. In most outcrops,
however, only the composite S0/S1 fabric was observed.
S0/S1 is refolded by conjugate asymmetric folds (F4)
that commonly have an associated crenulation cleavage
(S4) in schistose units (Figure 3B and 5B) and a spaced
cleavage in more massive units (Figure 6B). The S4
crenulation cleavages strike east-southeast and northnortheast and dip steeply. A plot of poles to S4 (Figure
2C) actually shows three clusters of data. The most
prominent cluster (#1) has a maximum representing an
S4 orientation of 098/78, although northerly dips also
occur. The other two clusters, #2 and #3, represent
Saskatchewan Geological Survey
Figure 6 - Field photographs of representative structures in
the Hickson Lake area: A) tight to isoclinal upright F2 folds
of thinly bedded psammite, pencil parallel to the axial plane
is 15 cm long; B) upright F4 folds of interbedded quartzite
and psammopelitic rocks, with southeast-striking S4
crenulation cleavage developed in the pelitic rocks, hammer
parallel to the S4 axial plane is 32 cm long; and C) gently
southwest-plunging, upright, open F3 fold of schlieren-rich
tonalite on the western side of Hickson Lake, view looking
southwest.
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steeply dipping S4 fabrics striking roughly north-south and about 060, respectively. Clusters #2 and #3 are
interpreted to represent one fabric that has been folded by folds related to cluster #1.
On the west side of Hickson Lake, the foliation in the Unit 7 leucotonalite is generally gently to moderately dipping
(30 to 60º) and is folded into upright, open, shallowly doubly plunging folds (Figure 6C) with northeast striking
axial planes (Figure 2B). The age of the folds relative to those on the eastern side of Hickson Lake is not certain, but
they are thought to post-date the tight to isoclinal folding and predate the late conjugate asymmetric folds, and have
thus been designated F3 folds. This folding event is similar in character and orientation to the latest phase of folding
in the Rottenstone Lake area, which post-dates migmatization.
6. Rottenstone Lake Area
The Rottenstone Lake map area lies within the ‘tonalite-migmatite complex’ (Lewry et al., 1981) in the central
Rottenstone Domain (Figure 1). This area was chosen for the initial phase of mapping to provide insight into the
origin and structural geometry of the ultramafic intrusions that host the Rottenstone Mine and Tremblay-Olsen
showing. This area comprises compositionally layered supracrustal rocks and granitoid sheets that pre-date and
contain the main tectonic fabric (Smain). These rocks have been intruded by large volumes of s-type migmatitic
tonalitic to granitic rocks that post date Smain. Overall, the rocks in this area are heterogeneous and the units
described below are defined based on the predominant rock type within a given area. Any particular outcrop of the
supracrustal units, however, may comprise a large proportion (>50%) of younger migmatitic granitoids. Similarly,
any given outcrop of the younger intrusive phases may contain abundant screens of earlier intrusive and
supracrustal units. Consequently, contacts between all units are gradational and the map pattern of folding (Figure
7) is based largely on small- and medium-scale structures. The units are described below in approximate order from
oldest to youngest.
a) Description of Rocks Units
Supracrustal Rocks
Unit 1: Migmatitic Psammitic to Pelitic Metasedimentary Rocks
Interlayered psammitic schists and psammopelitic to pelitic gneisses (Figure 8A) occur in a belt extending eastnortheast from the east end of Kenyan Lake and another just west of the north end of Kenyan Lake. The pelitic units
are strongly migmatitic and consist of biotite ± sillimanite (± garnet) melanosome and either white biotite-garnet ±
muscovite tonalitic leucosome (Figure 8B) or pink biotite monzogranite leucosome (Figure 8E). The variation in
leucosome composition is likely related to the composition of the metasedimentary rocks from which they were
derived. The proportion of melanosome to leucosome is <35% and the two are mixed at a scale of millimeters,
centimeters, and tens of centimeters. The leucosome occurs as irregular foliation-parallel lenses separated by seams
of biotite-rich melanosome and is interpreted to be in situ. The psammitic units are composed of fine-grained, wellfoliated biotite ± garnet (<2%, <3 mm) psammite with discrete foliation-parallel and cross-cutting veins of
leucosome of either the pink or white varieties described above (Figure 8E and F). The leucosome is injected, but
interpreted to be locally derived, and varies in proportion from >50% to <5%. The psammopelitic units have a
smaller proportion of in situ leucosome than the pelitic rocks, are commonly quite garnetiferous (up to 30%, 3 to
10 mm), but do not contain sillimanite. They commonly have injected as well as in situ leucosome components.
Unit 2: Mixed Supracrustal Rocks
A variety of supracrustal rocks including layered calc-silicate rocks, melanocratic biotite-hornblende-plagioclaserich metasedimentary/metavolcanic rocks, quartzite, psammite, migmatized psammopelite and pelite, as well as
amphibolite, form a belt between Kenyan Lake and Lower Rottenstone Lake. These rock types are interlayered on a
scale of tens of centimeters to tens of meters. The pelitic and psammopelitic units contain abundant in situ
leucosome (see above). The light green-weathering, fine-grained calc-silicate rocks (Figure 8C) are composed of
diopside-plagioclase-K-feldspar-titanite ± garnet, hornblende, quartz and minor biotite. The hornblende and biotite
replace diopside adjacent to granitoid veins and are interpreted to be the result of potassium metasomatism. Locally
the metasomatism is pervasive and little of the original diopside is preserved. The quartzite is fine-grained and buff
to pale pink weathering. The melanocratic metasedimentary/metavolcanic rocks are dark green to black weathering,
fine to coarse grained and comprised of biotite-hornblende-plagioclase-titanite-zoisite ± garnet. A layer-parallel
schistosity or gneissosity is common in the psammopelite, pelite, melanocratic supracrustal rocks, and amphibolite;
a weak irregular cleavage is developed in the quartz-rich rocks. All of these units and the fabric they contain are cut
by locally abundant biotite ± garnet tonalite and biotite-plagioclase pegmatite.
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Figure 7 - Geological sketch map of the Rottenstone Lake area. The Rottenstone deposit and Tremblay-Olsen showing are
shown by stars and occur in the hinge zones of gently northeast- and southwest-plunging F3 folds, respectively.
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Figure 8 - Field photographs of supracrustal rocks in the Rottenstone Lake area: A) Unit 2, interbedded psammite (i) that is
not migmatized and psammopelite (ii) with abundant in situ leucosome, Brunton compass is 10 cm long; B) Unit 2 pelitic
migmatite with biotite-sillimanite-garnet restite and white tonalitic leucosome, pencil is pointing at sillimanite and purple
garnet, silver tip is 2 cm long; C) interlayered greenish calc-silicate (diopside-bearing), psammite and quartzite of Unit 2, with
no in situ leucosome, pencil is 15 cm long; D) coarse-grained biotite-hornblende-plagioclase melanocratic metasedimentary/
metavolcanic rock of Unit 5, with abundant large plagioclase porphyroblasts and remnants of compositional layering;
E) migmatized psammopelitic, biotite-rich metasedimentary rocks of Unit 1, with lits-par-lits in situ pink granitic leucosome
(i), cut by a younger, slightly coarser grained, second generation of injected pink granite (ii), hammer is 32 cm long; and
F) biotite-rich, psammitic metasedimentary rocks of Unit 1, with no in situ leucosome, cut by injected pink granite leucosome
veins that have subsequently been folded.
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Unit 3: Mixed Supracrustal Rocks and Sheeted Granitoids
A package of the mixed supracrustal rocks similar to Unit 2 lies southeast of Rottenstone Lake. It contains >50%
layering- and foliation-parallel sheets of foliated granitoid rocks. The granitoid rocks are predominantly biotite
± hornblende granite to granodiorite, but diorite, tonalite, and quartz monzonite also occur. This package is
ubiquitously tightly to isoclinally folded and intruded by variable amounts of massive, K-feldspar porphyritic biotite
monzogranite that post-dates the main foliation.
Pre-Smain Granitoid Rocks
Biotite-Hornblende Monzogranite (Unit 4)
The biotite-hornblende monzogranite is heterogeneous and comprises biotite-hornblende quartz monzonite to
monzogranite and melanocratic metasedimentary/metavolcanic rocks. The biotite-hornblende granitoids have
textures that range from homogeneous K-feldspar megacrystic (Figure 9F) to faintly compositionally layered with
biotite ± hornblende-rich zones (Figure 9C). The compositionally layered areas commonly contain elongate
xenoliths of non-migmatized psammite. The supracrustal rocks generally preserve good compositional layering and
are predominantly biotite and hornblende bearing with large white plagioclase porphyroblasts (Figure 8D). The
melanocratic rocks are interlayered with minor amounts of psammopelitic rocks, with the more pelitic layers being
migmatized. Both the granitoids and the mafic metasedimentary rocks are generally well foliated and are locally cut
by massive, fine- to medium-grained biotite monzogranite (Figure 9A) that is commonly K-feldspar porphyritic.
Units 5 and 6 occur as irregular sheet-like bodies approximately parallel to the main tectonic fabric (Smain) which
they also contain.
K-feldspar Megacrystic Biotite ± Hornblende Monzogranite (Unit 5)
K-feldspar megacrystic biotite ± hornblende monzogranite and associated quartz monzonite to monzogranite,
granodiorite, diorite, and tonalite occupy two northeast-striking belts between Kenyan and Lower Rottenstone lakes.
Irregular intrusions of non-porphyritic, non-foliated, leucocratic, magnetite-bearing monzogranite that cut the
foliation are also part of this unit.
Biotite-Granodiorite (Unit 6)
A wide belt of homogeneous, light grey-weathering, foliated to gneissic biotite-granodiorite lies along the south arm
of Rottenstone Lake. Two narrow belts of this unit occur near the western edge of the map area and at the southeast
end of Kenyan Lake. This unit is locally K-feldspar porphyritic and the foliation is cut by irregular, curvilinear
granitoid dykes that range from fine-grained to pegmatitic and commonly have gradational contacts with the
granodiorite (Figure 9B). The granodiorite contains rare xenoliths of psammite and melanocratic supracrustal rock.
Post-Smain Intrusions
A variety of granitoid rocks post-date the main tectonic fabric in the supracrustal rocks. With the exception of Unit
7, they are heterogeneous in both composition and texture, contain abundant screens and inclusions of
metasedimentary rocks and biotite-rich schlieren and are massive to weakly foliated. The association of biotite-rich
schlieren with abundant metasedimentary screens suggests that the schlieren represent incompletely melted
remnants of metasedimentary rocks.
Biotite Monzogranite (Unit 7)
Homogeneous, pink-weathering, fine- to medium-grained, leucocratic (biotite <5%), biotite monzogranite occurs as
massive to weakly foliated sheets at both the outcrop and map scale. It has accessory titanite, apatite, and zircon and
ranges from equigranular to K-feldspar porphyritic (Figure 9F).
Biotite Tonalite to Granodiorite (Unit 8)
Fine- to medium-grained, leucocratic, white-weathering biotite tonalite to granodiorite, commonly with small
purple-red garnets (Figure 9G) and accessory zircon and monazite, underlies most of the central part of the map
area.
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Figure 9 - Field photographs of intrusive rocks in the Rottenstone Lake area: A) Unit 4, heterogeneous, foliated K-feldspar
porphyritic biotite-hornblende monzogranite, cut by a massive, fine-grained equigranular biotite monzogranite, pencil is
15 cm long; B) Unit 6, foliated to gneissic biotite granodiorite cut by biotite monzogranite dyke that has a gradational contact
with the granodiorite, silver tip of pencil is 2 cm long; C) Unit 4, heterogeneous, foliated biotite hornblende monzogranite
with remnants of melanocratic supracrustal rocks, Brunton compass is 10 cm long, not including black pointer; D) Unit 4,
homogeneous, foliated, K-feldspar megacrystic biotite-hornblende monzogranite, pencil is 15 cm long; E) Unit 9, texturally
and compositionally heterogeneous, pink biotite monzogranite to tonalite, weakly foliated with biotite schlieren, variably Kfeldspar porphyritic, pencil is 15 cm long; F) Unit 7, homogeneous, massive, to weakly foliated, K-feldspar porphyritic biotite
monzogranite, pencil is 15 cm long; G) Unit 8, massive to weakly foliated fine- to medium-grained, equigranular biotite
tonalite with rounded biotite-garnet-quartz restite inclusions, pencil is 15 cm long; and H) Unit 8, texturally and
compositionally heterogeneous white biotite tonalite to monzogranite, weakly foliated with abundant biotite schlieren and
biotite-rich layers, pencil is 15 cm long.
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Biotite Monzogranite to Tonalite (Unit 9)
Heterogeneous white- to pale pink-weathering biotite monzogranite to tonalite underlies much of the western part of
the area. It ranges from medium to coarse grained, biotite rich (20%) to biotite poor (<5%) and is variably coarsely
plagioclase megacrystic (>1.5 cm, Figure 9H). In the biotite-rich zones faint compositional layering is commonly
preserved, suggesting that these domains represent incompletely melted metasedimentary rocks.
Muscovite Granodiorite to Tonalite (Unit 10)
White- to buff-weathering, muscovite-bearing granodiorite to tonalite (Unit 10) underlies an area at the north end of
Lower Rottenstone Lake. It is medium to coarse grained, variably feldspar porphyritic with muscovite>biotite and
locally contains pinhead-size purple-red garnet. This unit commonly has abundant sericitized fractures that locally
show an incipient sinistral C-S fabric. Muscovite in this unit locally defines the foliation. In thin section, the
muscovite has a wormy intergrowth texture with quartz and with K-feldspar, which it replaces. Rare inclusions of
sillimanite in the cores of muscovite grains suggest that muscovite formed during retrograde conditions by the
reaction of sillimanite + K-feldspar to produce muscovite + quartz (i.e., second sillimanite isograd).
7. Structural Geology
The structural nomenclature used below is meant to indicate the relative age of fabrics and structures at Rottenstone
Lake only. No correlation with regional events or with events in the Hickson Lake area is implied.
The regional structural grain in the Rottenstone Lake area is northeast striking and moderately northwest dipping. It
is defined by the main tectonic fabric and the orientation of major lithological units (Figure 7). This orientation is
typical of much of the Rottenstone Domain and parallels the major domain boundaries of the Trans-Hudson Orogen
in this area.
Two pervasive phases of folding are distinguished in the Rottenstone Lake area; both post-date the main tectonic
fabric. Folding is best documented in the supracrustal rocks and foliated sheeted granitoids. Because of the degree
of deformation and metamorphism, what is interpreted as transposed bedding is referred to as compositional
layering. A strong foliation is defined by the peak metamorphic mineral assemblage and is parallel to both
compositional layering in the metasedimentary rocks and to the granitoid sheets. As no earlier structure was
recognized, this composite fabric is designated S1. The S1 fabric is folded by tight to isoclinal F2 folds. The axial
plane of these folds ranges from upright (Figure 10A) to recumbent (Figure 10B) and they are doubly plunging. One
map-scale F2 synform (Figure 7) has a moderately northwest dipping (~60°) axial plane. The map pattern suggests
that the massive, K-feldspar porphyritic, biotite monzogranite (Unit 7) in the southwest plunging hinge zone has
been affected by this phase of folding, although it cross-cuts the metamorphic fabric in the supracrustal rocks.
In areas dominated by supracrustal rocks, medium (20 m) and small-scale (<1 m) tight to isoclinal folds are
ubiquitous. Where this folding is symmetrical, an axial planar S2 foliation, which ranges from a crenulation
cleavage in biotite- and hornblende-rich supracrustal rocks and amphibolite, to a spaced cleavage in psammites and
quartz-rich metasedimentary rocks, is developed in the hinge zones of the folds. In areas of asymmetric folding, an
incipient S2 foliation is locally developed by attenuation along the long limbs of the folds. The S2 foliation is
generally parallel to the limbs of the folds, as expected for isoclinal folding. In areas where F2 folds are not
common, such as on the limbs of larger-scale F2 structures, the main foliation (Smain) is interpreted to be a composite
of compositional layering (transposed bedding) and the S1 peak metamorphic fabric transposed into the S2 axial
plane.
Relationships observed at the outcrop scale, between the metamorphic fabric and intrusive rocks, are reflected in the
map pattern. In domains of metasedimentary rocks, dykes of non-foliated biotite monzogranite and tonalite clearly
cut the metamorphic fabric, but also have branches that intruded along the foliation and were folded by F2 (Figure
10C). Commonly, wider dykes are not folded, but are transposed parallel with the limbs of the folds (Figure 10D).
This may be due to their original orientation and/or their large width relative to the scale of folding.
The other folding event recognized in the Rottenstone Lake area post-dates and refolds F2 structures and hence is
designated F3. Such folds are upright and open, with northeast-trending axial planes and gently northeast- and
southwest-plunging hinges. These folds are asymmetric with the long limbs parallel to the regional fabric and
dipping northwest, and the short limbs shallowly dipping to the southeast. These F3 folds are common in
metasedimentary screens (Figure 10F) within the younger tonalite and granitoid bodies and thus map scale screens
are also inferred to have this geometry (Figure 7). Outcrop scale F3 folds of the foliation in late tonalite to
monzogranite bodies are also common (Figure 10E).
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Figure 10 - Field photographs of representative structures in the Rottenstone Lake area: A) down-plunge view of an upright,
subvertically plunging tight to isoclinal F2 fold of interbedded quartzite and amphibolite of Unit 2, pencil parallel to axial
plane is 15 cm long; B) recumbent, tight to isoclinal F2 fold of thinly layered amphibolite of Unit 2, hammer parallel to the
axial plane is 32 cm long; C) non-foliated biotite monzogranite dyke cutting the main foliation in migmatitic psammopelite
(Unit 1), with an apophasis of the dyke intruded along the foliation and folded with it by an F2 fold, pencil is 15 cm long;
D) tight to isoclinal F2 folds of interbedded quartz arenite and amphibolite (Unit 2) with pink biotite monzogranite dykes (dk)
that cut compositional layering and the main foliation, but are folded by F2 ; E) open, upright F3 fold of biotite-garnet
tonalite (Unit 8) plunging gently northeast (away from viewer). Brunton compass is 10 cm long; and F) open, upright, gently
northeast plunging F3 fold of interbedded psammite, calc-silicate, and biotite tonalite (Unit 2), hammer parallel to axial trace
is 32 cm long.
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Implications for Ni-PGE Bearing Intrusions
Because the intrusion that hosted the Rottenstone deposit was completely removed during the mining it is not
possible to determine contact relationships with surrounding supracrustal rocks and the fabrics they contain.
Reconstructions of the intrusion based on drilling suggest that there are several sill-like bodies as opposed to a
single plug, and furthermore, that they are repeated by folding and/or change dip from steep to shallow towards the
east (SIR assessment report 74A07-SW-0036). The sill-like aspect and shallow dip are compatible with the
observation that the intrusion occurs in the hinge zone of a gently plunging F3 fold. The possible repetition of the
intrusion could result from folding by earlier isoclinal F2 folds.
The ultramafic intrusion that hosts the Tremblay-Olsen showing also occurs within the mixed supracrustal
succession, in the hinge zone of a shallowly plunging F3 fold. The intrusion appears to be roughly concordant with
the main fabric in the supracrustal rocks, although the contacts and the intrusion itself are not well exposed. So far it
had not been possible to determine whether the original intrusions were dykes, sills or plugs. It seems however, that
they only occur within the supracrustal rocks and are broadly concordant with the main tectonic fabric. This would
suggest that they pre-date the migmatitic granites and have therefore seen both phases of folding. Thus, even if they
were originally dykes or plugs at a high angle to bedding, they have likely been largely transposed into the main
tectonic fabric and hence resemble sills.
8. Discussion
The relationship between the two supracrustal successions (Units 1 and 2) on the east side of Hickson Lake (Figure
2) is not certain, as they are separated by a narrow zone of granodiorite. Several observations suggest that they
might be part of the same succession with a gradational contact.
1) Although the mixed supracrustal succession (Unit 2) has a wider variety of rock types, all are interbedded with
psammopelitic rocks similar to those in the other succession (unit 1).
2) Metagabbro occurs in both successions although it is more abundant in the mixed supracrustal succession.
3) Plagioclase porphyritic intermediate to felsic dykes are in both successions.
4) Both successions have undergone the same grade of metamorphism and the same deformational history.
There is the possibility, however, that they are separated by an early fault or an unconformity and were juxtaposed
prior to intrusion of the various dykes and prior to deformation and metamorphism. SHRIMP detrital zircon
geochronology on samples from both successions may help to distinguish between these alternatives.
If the two metasedimentary successions represent different lithotectonic assemblages, they may correlate with those
recognized elsewhere in the Rottenstone Domain. The psammopelitic package, although not migmatized, is
lithologically comparable to the ca. 1.865 Ga (Ansdell et al., 1999) Milton Island Assemblage on Reindeer Lake
that overlaps the boundary between the La Ronge and Rottenstone domains (Corrigan et al., 1998, 2001). The mafic
component in the mixed supracrustal unit could be related to volcanic rocks in the La Ronge arc, such as the Duck
Lake Assemblage (Maxeiner, 1997), or mafic volcanic rocks of the Clements Island Belt in the Rottenstone Domain
on Reindeer Lake (Corrigan et al., 2001). Despite the degree of migmatization, the same supracrustal units as in the
Hickson lake area are recognized in the Rottenstone Lake area and may be correlatives.
Because of the intervening Hickson Lake pluton, it is difficult to determine the relationship between the timing of
deformation and metamorphism in the migmatites (unit 7) and in the lower grade supracrustal rocks (Units 1 and 2)
on the east side of Hickson Lake. At Rottenstone Lake, the pre-Smain granodiorite to monzogranite sheets that are
interlayered with the metasedimentary rocks are lithologically similar to rocks of the Hickson Lake pluton. If they
are correlative, then D2 deformation and metamorphism at Hickson Lake must predate the main tectonic fabric and
therefore also both phases of folding at Rottenstone Lake. This hypothesis is presently being tested by U/Pb TIMS
geochronology being undertaken at Memorial University of Newfoundland.
The thermotectonic evolution of this part of the Rottenstone Domain is similar to that described elsewhere in the
Rottenstone Domain and in the adjacent La Ronge Domain by Maxeiner (1996) and Corrigan et al. (1997, 1998).
They describe an early bedding-parallel foliation at relatively low grade, associated with rare folds, which is only
preserved in the supracrustal rocks of the La Ronge and Rottenstone domains. This fabric may correlate with S1 in
the Hickson Lake area. The second event recognized by Corrigan et al. (1997, 1998) occurred during peak
metamorphism and resulted in reclined to recumbent southeast-verging folds and southeast-directed thrusting. This
timing and geometry is most compatible with the second deformation event in the Rottenstone Lake area. In the area
immediately south of the Wathaman Batholith in the Reindeer Lake area “the structural style is dominated by the
interference between orogen parallel inclined to recumbent folds, refolded by north-northeast trending, upright,
open F3 folds” (Corrigan et al., 1998), which corresponds closely to the deformation style in the Rottenstone Lake
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Summary of Investigations 2003, Volume 2
area. In the Reindeer Lake area, F3 folds affect the ca. 1.77 Ga Reynolds Island pluton (Corrigan et al., 2001),
which provides a maximum age for D3. This is compatible with ca. 1.815 Ga U/Pb ages (Clarke et al., in press) on
late S-type granitoids in the Davin Lake area that are inferred to be the same as the post Smain granitoids described in
this study that are clearly folded by the late upright open folds as well as the tight to isoclinal F2 folds.
It is interesting to speculate on the relationship between metamorphosed mafic/ultramafic dykes within supracrustal
rocks in the Hickson lake area and those that host mineralization at Rottenstone Lake. Within the waste pile at the
old Rottenstone mine, pieces of the intrusion that grade from igneous to metamorphic texture and composition were
sampled. They are interpreted to come from the margin of the body, which is known to have been deformed and
altered (L. Hulbert, pers. comm., 2003). The altered margin comprises actinolite-biotite schist that is similar in
mineralogy and texture to the small, metamorphosed mafic/ultramafic dykes observed in the Hickson Lake area.
Geochemical analyses are being conducted to test the hypothesis that they could be part of the same suite.
9. References
Ansdell, K.M., Corrigan, D., Stern, R., and Maxeiner, R.O. (1999): SHRIMP U-Pb geochronology of complex
zircons from Reindeer Lake, Saskatchewan: Implications for the timing of sedimentation and metamorphism in
the northwestern Trans-Hudson Orogen; Geol. Assoc. Can./Mineral. Assoc. Can., Jt. Annu. Meet., May 26-28,
Sudbury, abstr., p3.
Baldwin, D.A., Syme, E.C., Zwanzig, H.V., Gordon, T.M., Hunt, P.A., and Stevens, R.D. (1987): U-Pb ages from
the Lynn Lake and Rusty Lake metavolcanic belts, Manitoba: Two ages of Proterozoic magmatism; Can. J.
Earth Sci., v24, p1053-1063.
Clarke, D.B., Henry, A.S., and Hamilton, M.A. (in press): Composition, age and origin of granitoid rocks in the
Davin Lake area, Rottenstone Domain, Trans Hudson Orogen, northern Saskatchewan; LITHOPROBE
Publication.
Coolican, C. (2001); Structure, geochronology and geochemistry of the tonalite-migmatite complex and Wathaman
Batholith at Deception Lake, Saskatchewan Canada; unpubl. M.Sc. thesis, Univ. Saskatchewan, 180p.
Corrigan, D., Bashforth, A., and Lucas, S. (1997): Geology and structural evolution of the La Ronge–Lynn Lake
Belt in the Butler island area (parts of 64D-9 and -10), Reindeer Lake Saskatchewan; in Summary of
Investigations 1997, Saskatchewan Geological Survey, Sask Energy Mines, Misc. Rep. 97-4, p18-30.
Corrigan, D., MacHattie, T.G., Piper, L., Wright, D., Pehrsson, S., Lassen, B., and Chakungal. J. (1998): La Ronge–
Lynn Lake Bridge Project: New mapping results from Deep Bay (parts of 64D-6 and -7) to North Porcupine
Point (parts of 64E-7 and -8), Reindeer Lake; in Summary of Investigation 1998, Saskatchewan Geological
Survey, Sask Energy Mines, Misc. Rep. 98-4, p111-122.
Corrigan, D., Maxeiner, R., Bashforth, A., and Lucas, S. (1998): Preliminary report on the geology and tectonic
history of the Trans Hudson Orogen in the northwestern Reindeer zone, Saskatchewan; in Current Research,
Geol. Surv. Can. Pap. 98-1C, p95-106.
Corrigan, D., Maxeiner, R., and Harper, C.T. (2001): Preliminary U-Pb results from the La Ronge–Lynn Lake
Bridge Project; in Summary of Investigations 2001, Volume 2, Saskatchewan Geological Survey, Sask Energy
Mines, Misc. Rep. 2001-4.2, p111-115.
Fumerton, S.L., Stauffer, M.R., and Lewry, J.F. (1984): The Wathaman Batholith: Largest known Precambrian
pluton; Can. J. Earth Sci., v21, p1082-1097.
Gilboy, C.F. (1975); Foster Lake area: Reconnaissance geological mapping of 74A-6E, -7, -8W, -9W, -10, and
-11E; in Summary of Investigations 1975 by the Saskatchewan Geological Survey, Sask. Dep. Miner. Resour.,
p29-34.
__________ (1982): Geology of an Area Around Rottenstone and Dobbin Lakes; Sask. Energy Mines, Rep. 193,
68p.
Harper, C.T. (1986): Bedrock geology of the Windrum Lake area; in Summary of Investigations 1986,
Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 86-4, p8-18.
__________ (1990): Metallogenic environments: Deception Lake area; in Summary of Investigations 1990,
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__________ (1996): La Ronge–Lynn Lake Bridge Project: Sucker Lake–Fleming Lake area; in Summary of
Investigations 1996, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 96-4, p66-78.
Johnston, W.G.Q. and Thomas, M.W. (1984): Compilation Bedrock Geology Series, Reindeer Lake South, NTS
Area 64D; Sask. Energy Mines, Rep. 230, 1:250 000 scale map with marginal notes.
Lewry, J.F. (1975): Reindeer Lake South (NW Quarter): Reconnaissance geological mapping of 64D-11, -12,
-13(W) and -14(W); in Summary of Investigations 1975 by the Saskatchewan Geological Survey, Sask. Dep.
Miner. Resour., p24-28.
__________ (1976): Reindeer Lake north (SW Quarter) area: Reconnaissance geological mapping of 64E-3, -4, and
-6; in Summary of Investigations 1976 by the Saskatchewan Geological Survey, Sask. Dep. Miner. Resour.,
p29-35.
__________ (1983): Character and structural relations of the ‘McLennan Group’ meta-arkoses, McLennan-Jaysmith
lakes area; in Summary of Investigations 1983, Saskatchewan Geological Survey, Sask. Energy Mines, Misc.
Rep. 83-4, p49-55.
Lewry, J.F. and Collerson, K.D. (1990); The Trans-Hudson Orogen: Extent subdivisions and problems; in Lewry,
J.F. and Stauffer, M.R. (eds.), The Early Proterozoic Trans-Hudson Orogen of North America, Geol. Soc. Can.,
Spec. Pap. 37, 1-14.
Lewry, J.F., Stauffer, M.R., and Fumerton, S. (1981): Cordilleran style batholithic belt in the Churchill Province in
northern Saskatchewan; Precamb. Resear., v14, p227-313.
Mawdsley, J.B. (1946): Rottenstone Lake Area, Saskatchewan; Geol. Surv. Can. Map 433A, scale 1:253,440.
Maxeiner, R.O. (1996): Bedrock geology of the Henry Lake area (parts of NTS 64D-6 and -11), Northern La Ronge
Domain; in Summary of Investigations 1996, Saskatchewan Geological Survey, Sask. Energy Mines, Misc.
Rep. 96-4, p51-66.
__________ (1997): Geology of the Lawrence Bay (Reindeer Lake) area, northern La Ronge Domain; in Summary
of Investigations 1997, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 97-4, p3-17.
__________ (1999): La Ronge–Lynn Lake bridge: Geology of the Wapus Bay–Lowdermilk Bay (Reindeer Lake)
area; in Summary of Investigations 1999, Volume 2, Saskatchewan Geological Survey, Sask. Energy Mines,
Misc. Rep. 99-4.2, p143-158.
Maxeiner, R.O., Corrigan, D., Harper, C., MacDougall, D., and Ansdell, K. (2001): Lithogeochemistry, economic
potential and plate tectonic evolution of the ‘La Ronge–Lynn Lake Bridge’, Trans-Hudson Orogen; in
Summary of Investigations 2001, Volume 2, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep.
2001-4.2, CD-ROM, p87-110.
McMurchy, R.C. (1938a): Foster Lake Sheet (east half), northern Saskatchewan; Geol. Surv. Can., Map 433A, scale
1:253,440.
__________ (1938b): Foster Lake Sheet (west half), northern Saskatchewan; Geol. Surv. Can., Map 434A, scale
1:253,440.
Ray, G.E. (1974): Forster Lake (South)–La Ronge (NW) area: Reconnaissance geological survey; in Summary
Report of Field Investigations by the Saskatchewan Geological Survey, Sask. Dep. Miner. Resour., p14-19.
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Saskatchewan Geological Survey (2003): Geology, and Mineral and Petroleum Resources of Saskatchewan; Sask.
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Summary of Investigations 2003, Volume 2
Stauffer, M.R., Coleman, L.C., Langford, F.F., and Mossman, D.J. (1976): Reindeer Lake north (SE Quarter) area;
Reconnaissance geological mapping of 64E-1, 2, 7, 8; in Summary of Investigations 1976 by the Saskatchewan
Geological Survey; Sask. Dep. Miner. Resour., p24-28.
Williamson, A.E., Ansdell, K.M., and Maxeiner, R.O. (2000): Constraints on metamorphic conditions in the Milton
Island Metasedimentary Assemblage, Reindeer Lake; in Summary of Investigations 2000, Volume 2,
Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2000-4.2, p51-58.
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Summary of Investigations 2003, Volume 2