Saskatchewan Geological Survey 1 Summary of Investigations 2004, Volume 2 Overview of the Geochemistry of Archean and Proterozoic Rocks of the Phelps Lake Region, Mudjatik Domain, Hearne Province C.T. Harper Harper, C.T. (2004): Overview of the geochemistry of Archean and Proterozoic rocks of the Phelps Lake region, Mudjatik Domain, Hearne Province; in Summary of Investigations 2004, Volume 2, Saskatchewan Geological Survey, Sask. Industry Resources, Misc. Rep. 2004-4.2, CD-ROM, Paper A-7, 24p. Abstract Geochemical analyses of the major rock units from the Phelps Lake Project are reported and preliminary interpretations of the data presented. Archean tonalitic orthogneiss components of migmatites and gneissic tonalite intrusions are calcic, peraluminous rocks, with volcanic arc granite (VAG) affinity, high Sr/Y and La/Yb ratios, and a neutral to positive Eu anomaly. These are similar to the characteristics of Archean tonalite-trondhjemite- granodiorite suites that are thought to have formed through partial melting of a shallow subducting, garnet-bearing eclogitic, or basaltic crust. Archean granitic intrusions are calc-alkalic, peraluminous rocks with transitional VAG to syn-collisional granite (syn-COLG) affinities. The Archean Ennadai Group comprises mainly mafic with minor intermediate to felsic metavolcanic rocks and minor interlayered psammopelitic to pelitic schist and various iron formation facies. The mafic metavolcanic rocks are subalkaline, high-Fe to high-Mg tholeiites with transitional MORB to VAB character, which is typical of volcanic arc–back arc basin settings. The felsic metavolcanic rocks are calc-alkaline and typical of a volcanic arc setting. The chemical signature of 10 samples of various iron formation facies, particularly with a strong positive Eu anomaly, are similar to iron formations associated with volcanic-hosted massive sulphide deposits and suggests there may be potential for the Ennadai Group to host such deposits. Weakly to strongly iron sulphide-bearing (± chalcopyrite) metavolcanic rocks and mafic metavolcanic- hosted pyritic quartz veins, contain background to anomalous concentrations of base and precious metals. Proterozoic-aged rocks include the Hurwitz Group metasedimentary rocks and various syn- to post–Trans-Hudson intrusions. Pelitic and ferruginous pelitic schists and associated iron formations of the Hurwitz Group have similar rare earth element profiles as the North American Shale Composite. The general negative Eu anomaly of the ferruginous pelites and iron formations is characteristic of shale/mudstone-hosted iron formations. Proterozoic intrusions are subdivided into two age groups: the 1.85 to 1.8 Ga Hudson and the 1.76 to 1.75 Ga Nueltin granite suites. Chemically, both suites are silicic, potassic, calc-alkaline, and peraluminous granites. They mostly have syn- COLG affinity. The Nueltin granites have a tendency to be porphyritic, fluorite-bearing, and possibly REE- enriched. Perhaps the most interesting sample collected is a massive, lepidolite pegmatite boulder that has very high concentrations of Li, Rb, Cs, Nb, Ta, Sn, Be, Tl, Ga, and Ge, which is characteristic of complex, rare element pegmatites of the Bernic Lake type. Such pegmatites form from volatile-rich magmas commonly associated with post-tectonic granitic intrusions. The fluoritic Nueltin granite suite is a likely candidate from which the rare element pegmatite could have originated, and thus the boulder’s source may lie nearby to the north or northeast. Keywords: Phelps Lake, Archean, Proterozoic, geochemistry, intrusive rocks, Ennadai Group metavolcanics, iron formations, Hurwitz Group metasediments, mineral occurrences. 1. Introduction As part of the 1:100 000 scale geological mapping component of the Phelps Lake Project (Figure 1) completed from 2001 to 2003 (Harper et al., 2001, 2002a, 2003; Coulson et al., 2001), 112 rock samples were collected for geochemical analyses. Samples of Archean rocks include: tonalitic orthogneiss from migmatites, foliated to gneissic tonalitic and granitic intrusions, and mafic and felsic metavolcanic rocks and iron formations of the Ennadai Group. Proterozoic rocks sampled include: Hurwitz Group metasediments and rare metavolcanic rocks, Wollaston Supergroup pelitic gneiss, and the Hudson and Nueltin granite suites. Thirty-five samples representing a variety of metavolcanic-, metasediment-, and granitoid-hosted mineral occurrence types were collected from outcrop, felsenmeer, and transported boulders to test their metal endowment. All samples were analysed at Activation Laboratories Ltd., Ancaster, Ontario for major oxides and a group of trace and rare earth elements (see Appendix 1 for analytical details). The geochemical data for samples collected during the 2001 field season, along with the till geochemistry (Campbell, 2001) and mineral deposit studies geochemistry (MacDougall, 2001), was previously released without interpretation, as Saskatchewan Industry and Resources Data File 21 (Harper et al., 2002b). Other geochemical studies related to the project include those of: Coulson (2002) for Ennadai Group metavolcanic rocks
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Saskatchewan Geological Survey 1 Summary of Investigations 2004, Volume 2
Overview of the Geochemistry of Archean and Proterozoic Rocks of the Phelps Lake Region, Mudjatik Domain, Hearne Province
C.T. Harper
Harper, C.T. (2004): Overview of the geochemistry of Archean and Proterozoic rocks of the Phelps Lake region, Mudjatik Domain, Hearne Province; in Summary of Investigations 2004, Volume 2, Saskatchewan Geological Survey, Sask. Industry Resources, Misc. Rep. 2004-4.2, CD-ROM, Paper A-7, 24p.
Abstract Geochemical analyses of the major rock units from the Phelps Lake Project are reported and preliminary interpretations of the data presented. Archean tonalitic orthogneiss components of migmatites and gneissic tonalite intrusions are calcic, peraluminous rocks, with volcanic arc granite (VAG) affinity, high Sr/Y and La/Yb ratios, and a neutral to positive Eu anomaly. These are similar to the characteristics of Archean tonalite-trondhjemite-granodiorite suites that are thought to have formed through partial melting of a shallow subducting, garnet-bearing eclogitic, or basaltic crust. Archean granitic intrusions are calc-alkalic, peraluminous rocks with transitional VAG to syn-collisional granite (syn-COLG) affinities. The Archean Ennadai Group comprises mainly mafic with minor intermediate to felsic metavolcanic rocks and minor interlayered psammopelitic to pelitic schist and various iron formation facies. The mafic metavolcanic rocks are subalkaline, high-Fe to high-Mg tholeiites with transitional MORB to VAB character, which is typical of volcanic arc–back arc basin settings. The felsic metavolcanic rocks are calc-alkaline and typical of a volcanic arc setting. The chemical signature of 10 samples of various iron formation facies, particularly with a strong positive Eu anomaly, are similar to iron formations associated with volcanic-hosted massive sulphide deposits and suggests there may be potential for the Ennadai Group to host such deposits. Weakly to strongly iron sulphide-bearing (± chalcopyrite) metavolcanic rocks and mafic metavolcanic-hosted pyritic quartz veins, contain background to anomalous concentrations of base and precious metals.
Proterozoic-aged rocks include the Hurwitz Group metasedimentary rocks and various syn- to post–Trans-Hudson intrusions. Pelitic and ferruginous pelitic schists and associated iron formations of the Hurwitz Group have similar rare earth element profiles as the North American Shale Composite. The general negative Eu anomaly of the ferruginous pelites and iron formations is characteristic of shale/mudstone-hosted iron formations. Proterozoic intrusions are subdivided into two age groups: the 1.85 to 1.8 Ga Hudson and the 1.76 to 1.75 Ga Nueltin granite suites. Chemically, both suites are silicic, potassic, calc-alkaline, and peraluminous granites. They mostly have syn-COLG affinity. The Nueltin granites have a tendency to be porphyritic, fluorite-bearing, and possibly REE-enriched. Perhaps the most interesting sample collected is a massive, lepidolite pegmatite boulder that has very high concentrations of Li, Rb, Cs, Nb, Ta, Sn, Be, Tl, Ga, and Ge, which is characteristic of complex, rare element pegmatites of the Bernic Lake type. Such pegmatites form from volatile-rich magmas commonly associated with post-tectonic granitic intrusions. The fluoritic Nueltin granite suite is a likely candidate from which the rare element pegmatite could have originated, and thus the boulder’s source may lie nearby to the north or northeast.
Keywords: Phelps Lake, Archean, Proterozoic, geochemistry, intrusive rocks, Ennadai Group metavolcanics, iron formations, Hurwitz Group metasediments, mineral occurrences.
1. Introduction As part of the 1:100 000 scale geological mapping component of the Phelps Lake Project (Figure 1) completed from 2001 to 2003 (Harper et al., 2001, 2002a, 2003; Coulson et al., 2001), 112 rock samples were collected for geochemical analyses. Samples of Archean rocks include: tonalitic orthogneiss from migmatites, foliated to gneissic tonalitic and granitic intrusions, and mafic and felsic metavolcanic rocks and iron formations of the Ennadai Group. Proterozoic rocks sampled include: Hurwitz Group metasediments and rare metavolcanic rocks, Wollaston Supergroup pelitic gneiss, and the Hudson and Nueltin granite suites. Thirty-five samples representing a variety of metavolcanic-, metasediment-, and granitoid-hosted mineral occurrence types were collected from outcrop, felsenmeer, and transported boulders to test their metal endowment. All samples were analysed at Activation Laboratories Ltd., Ancaster, Ontario for major oxides and a group of trace and rare earth elements (see Appendix 1 for analytical details). The geochemical data for samples collected during the 2001 field season, along with the till geochemistry (Campbell, 2001) and mineral deposit studies geochemistry (MacDougall, 2001), was previously released without interpretation, as Saskatchewan Industry and Resources Data File 21 (Harper et al., 2002b). Other geochemical studies related to the project include those of: Coulson (2002) for Ennadai Group metavolcanic rocks
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Figure 1 - Location of the Phelps Lake Project area with respect to A) major lithostructural domains, and B) the regional geological setting.
LEGEND
Metasedimentary rocks (largely >2.5 Ga)
Mafic to ultramafic gneisses and intrusions (2.6 Ga)
Diabase dikes and sills (1.28 to 1.10 Ga)
Metasedimentary rocks (2.45 to 1.83 Ga)
Metavolcanic rocks (largely >2.5 Ga)
Felsic granitoids (3.2 to 2.5 Ga)
Metavolcanic rocks (1.92 to 1.87 Ga)
Wathaman Batholith: granitic rocks (1.86 Ga)
Mylonite
Felsic granitoids and migmatites (1.92 to 1.77 Ga)
Athabasca Group: sandstones (1.75 to 1.60 Ga)
25 0 25 50 75 100Scale
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from part of the main Ennadai Greenstone Belt; Rainville (2002) and Rainville et al. (2002) for amphibolite rocks equated with mafic metavolcanic rocks of the Ennadai Group from an outlying belt at Bonokoski Lake; MacDougall (2002) who summarized the geochemical results from his two field seasons of sampling various mineral occurrences throughout the Phelps Lake region; and Senkow (2003) for some unusual Hurwitz Group dolomitic marbles at Many Islands Lake.
The main purpose of this paper is to present the geochemical data and provide a brief overview of some of the important interpretations that have been derived from the data. For the major rock types, samples were collected which showed the least potential for alteration and thus reduce the affects of element mobility. Harker-type plots were used to determine element mobility in the different suites of rocks, but will not be discussed further.
2. General Geology The Phelps Lake map area (NTS 64M) lies in the western part of the Hearne province, mainly in the northern Mudjatik Domain, but also includes part of the Wollaston Domain in the southeast corner. In the extreme northwest corner, mylonitic granites and amphibolites probably mark the southeast limit of the Striding-Athabasca mylonite zone (Hanmer and Kopf, 1993; Hanmer, 1997), which occurs on the Hearne side of the Snowbird Tectonic Zone (STZ). The STZ marks the boundary between the Rae and Hearne cratons.
The Phelps Lake area is largely underlain by Archean granitoid rocks which locally form an older basement migmatite complex (ca. 3.3 to 2.82 Ga; e.g., Aspler and Chiarenzelli, 1996; Orrell et al., 1999; Harper et al., 2004) to younger Archean supracrustal rocks, generally referred to as the Ennadai Greenstone Belt. This belt is part of a regionally discontinuous supracrustal belt that extends over 700 km from northeast Saskatchewan to Rankin Inlet on Hudson Bay. The metavolcanic and metasedimentary rocks (ca. 2.73 to 2.68 Ga) of the Saskatchewan portion of the Ennadai Greenstone Belt (Figure 1) were informally referred to as the Ennadai Group by Macdonald (1984) and that term was adopted by Reilly (1989, 1993) and by Harper et al. (2001, 2002a, 2003). These rocks were intruded by ca. 2.72 to 2.6 Ga mafic to felsic plutons (Peterson and Lee, 1995; Peterson et al., 2000; Harper et al., 2004), that were contemporaneous with volcanic activity and predated late Archean deformation and metamorphism at ca. 2.55 to 2.5 Ga (Davis et al., 2000). These plutons are dominantly well-foliated to gneissic tonalite and granite-leucogranite.
Paleoproterozoic Hurwitz Group metasedimentary rocks (ca. 2.4 to 1.9 Ga) are more widely distributed than previously indicated, whereas the partially time-equivalent Wollaston Supergroup metasedimentary rocks (ca. 2.1 to 1.9 Ga) are only in the southeast. Paleoproterozoic gabbros, leucogranites, granites, and leucotonalites (ca. 1.85 to 1.75 Ga) intruded these rocks. The youngest rocks are west- and northwest-trending diabase dykes; the former possibly belonging to the ca. 2.19 Ga Tulemalu or 1.9 Ga Chipman dyke swarms (Tella et al., 1997; Williams et al., 1999), and the latter, mainly defined by aeromagnetic trends, are probably related to the ca. 1.27 Ga McKenzie swarm (LeCheminant and Heaman, 1989).
The area has been affected by multiple thermotectonic events, during the Archean and subsequently the Paleoproterozoic Trans-Hudson orogeny. The rocks generally exhibit amphibolite facies mineral assemblages, with a gradual increase from lower amphibolite grade in Ennadai Group and Hurwitz Group rocks near the Northwest Territories border, to upper amphibolite grade southwestwards; locally some rocks attained granulite facies conditions. As all rocks, except the youngest intrusive rocks, have undergone some metamorphism, the prefix ‘meta’ will be dropped, for simplicity, in the remainder of the paper.
3. Geochemistry of the Archean Migmatites and Intrusive Rocks The migmatite complex comprises multiple, predominantly tonalitic intrusive (orthogneiss) components, which are geochemically similar to the younger tonalite gneisses (Appendix 2). Although the alkali elements are generally the most mobile elements, their relatively tight clustering on bivariant plots (not shown) and on Figure 2 suggests that their mobility was minimal, and as such they can provide appropriate chemical characterization. On an alkalis versus silica plot (Frost et al., 2001) analyses of the migmatite and tonalite samples are characterized as calcic intrusions, those of granitic intrusions are transitional from alkali-calcic to calc-alkalic (Figure 2A). On the ASI (alumina saturation index) versus Na+K/Al plot (ibid), all analyses, with the exception of one gabbro, have peraluminous characteristics, with a clear distinction between tonalitic and granitic rocks (Figure 2B). On a tectonic discrimination diagram (Pearce et al., 1984) migmatitic and gneissic tonalites have relatively low Y + Nb over Rb ratios (Figure 2C), similar to modern volcanic arc granites (VAG); granitic rocks show a transitional character between the VAG and syn-collision granites (syn-COLG). This distinction in tectonic environments is also suggested in the εNd values (see Harper and van Breemen, this volume) with tonalitic rocks having positive εNd values (i.e., juvenile mantle derivation), and granitic rocks having slightly negative εNd (i.e., older crustal
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involvement, substantiated by presence of inherited Mesoarchean zircon cores). Thus a collisional setting may have developed between emplacement of the ca. 2.7 Ga tonalites and formation of the ca. 2.68 Ga granites.
On extended chondrite-normalized trace element plots (after Taylor and McLennan, 1985), with the exception of migmatite sample 0111-128, the migmatites and tonalite gneisses have similar profiles (Figure 3A), and share strong negative Nb and moderate negative Ti anomalies. Both rock types have elevated light rare earth element (LREE)
contents relative to their heavy rare earth element (HREE) contents and their analyses also show both negative and positive Zr anomalies. In addition, the tonalitic migmatites and tonalite gneisses have low Y (average ~5 ppm), high Sr/Y (~38 to 230) and La/Yb (~10 to 80) ratios, and have neutral to slightly positive Eu ratios. Such geochemical features are typical of Archean tonalites (Sandeman et al., 2000; Selbekk and Skjerlie, 2000) that are thought to have formed through partial melting of a shallow subducting, garnet-bearing basaltic crust (Drummond et al., 1996; Smithies and Champion, 2000; Martin and Moyen, 2002; Smithies et al., 2003).
Extended chondrite-normalized trace element signatures (after Taylor and McLennan, 1985) of the Archean granites (Figure 3B) are somewhat similar to those of the tonalitic rocks, but generally have slightly higher normalized concentrations. Small positive and negative anomalies are indicated for Zr, Sm, and Eu; negative Ti anomalies are more pronounced; and the HREE profile is flat. The similarity to VAG setting is shown in the REE normalized profiles for the migmatites and tonalites (Figure 4A) and granites (Figure 4B). Both groups straddle the VAG=1 profile, with the migmatites and tonalites having a negative slope for the HREE and the granites displaying both positive and negative Eu anomalies. The strong association of the granites to VAG is perhaps contradictory to the notion of crustal contamination in the formation of the granites, but it may also indicate the relative importance of subduction-related processes in their formation. Lending support to the subduction process is the U-Pb SHRIMP age of 2681 Ma (Harper and van Breemen, this volume) obtained on one such granite that is identical to the 2681 to 2682 Ma ages of Ennadai Group felsic volcanic rocks (Chiarenzelli and Macdonald, 1986; Harper et al., 2004).
4. Ennadai Group Volcanic and Sedimentary Rocks
Volcanic rocks of the Ennadai Group are dominated by massive and pillowed mafic (basaltic) flows, lesser mafic tuffaceous rocks, and minor intermediate to felsic volcanic rocks (Appendix 3). Interlayered sedimentary rocks include psammopelitic-pelitic schist and gneiss, and various facies of iron formation. The geochemical character of Ennadai Group mafic volcanic rocks from Bonokoski Lake (Rainville, 2002) and from the main Ennadai Greenstone Belt (Coulson, 2002) was described as predominantly subalkaline, and both high-Fe and high-Mg tholeiitic in character. The few intermediate to felsic volcanic rocks analysed showed calc-alkaline character.
Figure 2 - Geochemical diagrams for the Archean migmatites and intrusive rocks. A) Alkalis vs. SiO2 diagram (Frost et al., 2001) to show alkalic to calcic character; B) ASI (Al/(Ca-1.67P+Na+K)) versus Na+K/Al diagram (Frost et al., 2001); and C) Rb versus Y+Nb (Pearce et al., 1984) granitic tectonic discrimination diagram; ORG, ocean ridge granite; syn-COLG, syn-collision granite; VAG, volcanic arc granite; and WPG, within-plate granite.
Saskatchewan Geological Survey 5 Summary of Investigations 2004, Volume 2
Figure 3 - Extended chondrite-normalized trace element plots for: A) the Archean migmatites and tonalite gneisses and B) the Archean granitic intrusive rocks. Chondritic normalizing values after Taylor and McLennan (1985).
Analytical results from additional samples collected across the Phelps Lake region (this study) confirm the subalkaline tholeiitic nature, although one sample (0411-0003) from the western edge of the EGB shows komatiitic basalt affinity (Figure 5A). Rainville (2002) noted the transitional nature of the volcanic rocks from MORB to VAB, typical of volcanic arc–back arc basin settings. The additional data presented here, supports the transitional MORB–VAB chemical character of the volcanic rocks. This is illustrated in Meschede’s (1986) Nb-Zr-Y ternary plot (Figure 5B) and Wood’s (1980) Hf-Th-Ta ternary diagram (Figure 5C), but shows exclusive back-arc basin basalt affinity on Cabanis and Lecolle’s (1989) Y-La-Nb ternary diagram (Figure 5D). Pearce’s (1996) N-MORB-normalized abbreviated ‘spider’ diagrams, which are used to discriminate different tectonic environments, also show that the Ennadai mafic volcanic rocks have a transitional setting between MORB and VAB (Figure 6A and B). Felsic volcanic rocks show profiles typical of more evolved volcanic arc rocks (Figure 6C; Pearce, 1996), with negative Nb and Ti anomalies.
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Figure 4 - Volcanic arc granite rare earth element normalized plot for: A) the Archean migmatites and tonalitic gneisses and B) the Archean granitic intrusive rocks.
Oxide, sulphide, and silicate facies iron formations are typically interlayered on a metre to ten metre scale with the mafic volcanic rocks, and with the new Federal-Provincial aeromagnetic maps can be traced for 10 to 20 km along strike. They were sampled at various locations in the main Ennadai Greenstone Belt, at Bonokoski Lake, and elsewhere in the Phelps Lake region. The iron content of these samples ranges from 7.77 to 50.34%, the former from a sample consisting mostly of the ‘cherty’ part of a banded oxide-facies iron formation, and the latter from a metre-thick magnetite layer at Bonokoski Lake. Samples 0111-CAMP and 0311-2056 are massive pyrrhotite-bearing boulders. None of the iron formations contained any notable gold concentrations and only sample 0311-
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Figure 5 - Chemical diagrams for the Ennadai Group volcanic rocks. A) Jensen (1976) cation plot. B), C), and D) Basalt discrimination diagrams; CAB, calc-alkaline basalt; IAT, island arc tholeiite; E-MORB, evolved; EVM, Ennadai mafic volcanic rocks; EVM Bono, from Bonokoski Lake; EVFr, Ennadai felsic volcanic (rhyolitic) rocks.
2056 had a higher copper content of 500 ppm. With the exception of the massive iron sulphide boulder (0311-2056) and a notably garnet-rich silicate facies boulder from Phelps Lake, all the samples have nearly identical chondrite-normalized extended element profiles (Figure 7). They have a slightly elevated LREE signature, a prominent positive Eu anomaly, and very flat HREE signature. Positive Eu anomalies in iron formations typically result from hot hydrothermal fluids, with low detrital input, and can be associated with volcanic-hosted massive sulphide (VHMS) deposits (Peter, 2003). Sample 0311-2056 collected east of Misaw Lake, has no Eu anomaly, which according to Peter (2003) might suggest there is a greater clastic component or perhaps the rocks were more distal from the fluid source. The extended trace element plot also reveals a strong negative Nb anomaly, moderate to strong negative Zr and very strong negative Ti anomaly, which would all be consistent with chemical sedimentation having little detrital material being contributed to the sediment.
5. Hurwitz Group (Wollaston Group) Samples of Hurwitz Group rocks included pelite, ferruginous pelite, and various related facies of iron formation, calc-silicates and marbles, and rhyolite (Appendix 4). A single pelitic gneiss sample from the Wollaston Domain was collected for comparison to the Hurwitz Group pelites (Appendix 4).
Two analyses of lower amphibolite facies Hurwitz Group pelites and one analysis of an upper amphibolite facies Wollaston Supergroup pelite are shown on a chondrite-normalized extended trace element plot (Figure 8A). They have nearly identical profiles, with a steep LREE profile relative to the HREE and a negative Eu anomaly, which is characteristic of the North American Shale Composite (see Peter, 2003). The pelitic rocks also have consistent negative Nb, Zr, and Ti anomalies.
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The ferruginous pelites of the Hurwitz Group typically contain several percent magnetite or pyrite and locally develop into banded iron formations of oxide or sulphide facies. They are most common in the lower pelitic sequence (Harper et al., 2001, 2002a). Their iron content ranges from 7.1 to 35.7% and they generally have background concentrations of base and precious metals (Appendix 4). These rocks have nearly identical chondrite-normalized extended element profiles to the ‘normal’ pelites (Figures 8A and 8B). In comparison to the Ennadai Group iron formations, the Hurwitz Group ferruginous pelites and iron formations have parallel profiles, but are a factor of 10 times higher than the Ennadai Group (compare with Figure 7). They also have a slightly negative Eu anomaly, which is characteristic of shale/mudstone-hosted iron formations and similar to Red Sea metalliferous sediments (Peter, 2003). The Hurwitz Group ferruginous pelites and iron formations also have strong negative Nb and Ti anomalies and a neutral to weak negative Zr anomaly. Sample 0311-1146, from a boulder of specular hematite-bearing Hurwitz Group iron formation, has a parallel profile to the majority of the samples, but is more than a factor of 10 lower than the other ferruginous Hurwitz Group rocks, suggesting perhaps an association with volcanic rocks.
Two dolomitic marble and two hematitic quartz-veined marble samples (Appendix 4) were part of a B.Sc. project by Senkow (2003) to determine the correct mineralogy of a suspected rhodochrosite occurrence at the southwest end of Many Islands Lake. Petrography, cathodoluminescence, and X-ray diffraction analyses were completed on several samples, in
addition to wholerock geochemistry to determine if the rocks were enriched in Mn and/or other metals (e.g., Cu, Pb, Zn, and Ag). Manganese enrichment was not noted and only one sample (0211-1003) had slightly anomalous Cu and Zn concentrations relative to the other samples. Rhodochrosite was not identified, but the pink to red carbonate mineral was identified as dolomite and/or ferroan dolomite (Senkow, 2003; D. Quirt, pers. comm., 2004) and was accompanied by two types of hematite. The marble samples and two calc-silicate samples have similar chondrite-
Figure 6 - Abbreviated N-MORB-normalized “spider” diagrams (after Pearce, 1996) for Ennadai Group volcanic rocks; A) regional samples, B) samples from Bonokoski Lake, and C) felsic volcanic rocks.
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Figure 7 - Chondrite-normalized extended element profiles for various Ennadai Group iron formation facies. Chondrite normalizing values from Taylor and McLennan (1985).
normalized extended trace element profiles (Figures 8C and 8D) as the pelitic rocks, but have a stronger negative Ti anomaly, a neutral Y to slightly positive Y anomaly, and both negative and positive Zr anomalies.
6. Paleoproterozoic Intrusions Two periods of Paleoproterozoic granitoid plutonism have been documented in the Northwest Territories and Nunavut (Peterson and van Breemen, 1999; Peterson et al., 2000, 2002) and are referred to as the Hudson granitoids (ca. 1850 to 1810 Ma) and the Nueltin granite suite (ca. 1760 to 1750 Ma); the latter has an associated felsic volcanic suite, the Pitz Formation. In the Phelps Lake area weakly foliated granite, and massive leucotonalite and leucogranite intruded Hurwitz Group rocks, confirming their Proterozoic age. Massive, porphyritic, fluorite-bearing granites were considered to be Nueltin-type granites (Appendix 5). The fluorine content of three fluorite-bearing samples (0211-1162, -1163, and -1177) from the Spratt Lake area ranged from 0.11 to 0.31%, whereas, an analysis of a non-fluorite-bearing sample yielded 0.03% F (Appendix 5). Aphanitic felsite, found in two locations in the northeast quarter of 64M (Harper et al., 2002a), were thought to be possible equivalents of the Pitz Formation. A single sample of the felsite is included in Appendix 5 and plotted with the Nueltin granites. Several of these Proterozoic intrusions have now been dated by U-Pb zircon (Heaman et al., 2003; Harper et al., 2004) and U-Pb SHRIMP zircon (Harper and van Breemen, this volume) techniques, establishing affinities to both periods of plutonism. A weakly deformed, east-trending gabbro dyke that intruded strongly foliated granite in the southeast margin of the Striding-Athabasca mylonite zone is believed to be a Proterozoic-aged dyke, and is included in Appendix 5. Also of interest is a sample (0211-1501) collected from a boulder north of Keseechewun Lake of a, presumably post-tectonic, massive lepidolite-bearing pegmatite (Appendix 5).
Chemically the Proterozoic Hudson and Nueltin-type granites are silicic, potassic rocks (Appendix 5) that are characterized as calc-alkaline and peraluminous granites (Figures 9A and 9B). On the granite discrimination diagrams of Pearce et al. (1984), they show a stronger affinity to syn-COLG (Figures 9C and 9D). Sample 0211-1163, a REE-enriched fluoritic granite plots in the within-plate granite (WPG) field (Figures 8C and 8D); this probably reflects an associated Y enrichment. On the chondrite-normalized extended trace element diagrams (Figures 10A and 10B), the Hudson and Nueltin granites have very similar profiles, with enriched LREE relative to the HREE, strong negative Nb and Ti anomalies, and a generally weak negative Eu anomaly. These features are similar to the chemical patterns obtained by Peterson et al. (2002) for Hudson and Nueltin granites in Nunavut. Other features in common are the abundant inherited zircon cores in the Hudson granites and enriched εNd value of -10.74 for one of the SHRIMP-dated Hudson granites (see Harper and van Breemen, this volume), also indicative of crustal melting of an Archean source.
Saskatchewan Geological Survey 10 Summary of Investigations 2004, Volume 2
Fig
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Figure 9 - Geochemical diagrams for the Proterozoic intrusions. A) Alkalis versus silica (Frost et al., 2001); B) ASI Index versus Na+K/Al (Frost et al., 2001); and C) and D) Tectonic environment granite discrimination diagrams (Pearce et al., 1984).
The lepidolite pegmatite sample (0211-1501, Appendix 5) has very high concentrations of Li, Rb, Cs, Nb, Ta, Sn, Be, Tl, Ga, and Ge as well as exceptionally low MgO, CaO, Fe2O3, TiO2, Sr, Ba, and REE concentrations. Some of these features are clearly discernible on the chondrite-normalized extended element diagram (Figure 11) comparing the pegmatite with selected Hudson and Nueltin granites. This chemical signature is characteristic of S-type, complex rare element granitic pegmatites (Breaks and Moore, 1992; Shearer et al., 1992; Sillitoe, 1996) as well as ore-grade lithium pegmatites such as the Bernic Lake pegmatites (Goad and Černý, 1981). These types of pegmatites typically form from volatile-rich magmas commonly associated with post-tectonic granitic intrusions (London, 1992; Shearer et al., 1992). The fluoritic Nueltin granite suite is a likely candidate from which volatile-rich magma could have originated. The Li content of several of these granites at Spratt Lake average about 45 ppm, which is just above the average granite content of 30 ppm (see Table B in MacDougall, 2002). Clasts of this type of pegmatite generally are not likely to travel very far, thus boulder prospecting should be effective in finding a source area for this prospective rare element pegmatite.
7. Iron Sulphide– and Quartz Vein–bearing Samples In addition to the samples of iron formation and other intrusion- and mafic volcanic-hosted mineral occurrences listed in Appendices 2 to 5, 11 samples of iron sulphide–bearing rocks, many of which were locally transported boulders, were collected and analysed for a suite of trace elements (Appendix 6). Most of these samples are pyrite and or pyrrhotite bearing with or without trace amounts of chalcopyrite. Several samples contained pyritic quartz veins and were collected specifically to check for possible gold enrichment. A number of these samples contain threshold to anomalous concentrations of Cu (maximum 883 ppm), Zn (maximum 1180 ppm), and Au (maximum 533 ppb). Sample 0111-4032, a mafic volcanic rock with pyritic quartz veins and which contains 533 ppb Au, was collected from an area of known mafic volcanic-hosted auriferous quartz vein showings, approximately 6.5 km west of the southwest end of Hatle Lake. This location is also near the iron formation-hosted Nirdac Creek gold occurrence (Assessment Files 64M-0006 and 64M-14-0006).
Saskatchewan Geological Survey 12 Summary of Investigations 2004, Volume 2
Figure 10 - Chondrite-normalized extended element diagrams for A) Hudson granites, and B) Nueltin granites and felsite. Chondrite normalizing values are from Taylor and McLennan (1985).
8. Conclusions Based on the geochemical analysis of the major rock units from the Phelps Lake Project presented here the following conclusions can be made:
1) Archean tonalitic migmatites and tonalite gneiss intrusions are calcic, peraluminous rocks, with apparent VAG affinity, high Sr/Y and La/Yb ratios, and neutral to positive Eu anomaly. These characteristics are similar to those of Archean tonalite-trondhjemite-granodiorite suites, that are thought to have formed through partial melting of a shallow subducting, garnet-bearing, basaltic crust (Drummond et al., 1996; Smithies and Champion, 2000).
2) Archean granitic intrusions are calc-alkalic, peraluminous rocks with transitional VAG to syn-collisional granite affinities.
3) The Archean Ennadai Group mafic volcanic rocks are subalkaline, high-Fe to high-Mg tholeiites with transitional MORB to VAB character, which is typical of volcanic arc-back arc basin settings. The felsic
Saskatchewan Geological Survey 13 Summary of Investigations 2004, Volume 2
Fig
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11 -
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5).
Saskatchewan Geological Survey 14 Summary of Investigations 2004, Volume 2
volcanic rocks are calc-alkaline, and typical of a volcanic arc setting. The chemical signature of the various iron formation facies particularly with a strong positive Eu anomaly are typical of iron formations formed from hydrothermal fluids and possibly associated with volcanic-hosted massive sulphide deposits.
4) Several samples of weakly to strongly iron sulphide–bearing volcanic rocks and mafic volcanic-hosted pyritic quartz veins, although not providing spectacular geochemical results indicate there may be potential for base and precious metal occurrences/deposits in the region.
5) Hurwitz Group pelitic and ferruginous pelitic schists and associated iron formations have similar rare earth element profiles as the North American Shale Composite. The general negative Eu anomaly of these ferruginous pelites and iron formations is characteristic of shale/mudstone-hosted iron formations and Red Sea metalliferous sediments (Peter, 2003); however, they show only background base and precious metal concentrations.
6) The Proterozoic intrusions are subdivided into two age groups, the 1.85 to 1.8 Ga Hudson granite and the 1.76 to 1.75 Ga Nueltin granite suites. Chemically, both suites are silicic, potassic, calc-alkaline, and peraluminous, with syn-COLG affinity. The Nueltin granites have a tendency to be porphyritic, fluorite-bearing, and may be REE-enriched.
7) An undeformed, lepidolite pegmatite boulder, that has very high concentrations of Li, Rb, Cs, Nb, Ta, Sn, Be, Tl, Ga, and Ge, is similar to complex, rare element pegmatites of the Bernic Lake type (Goad and Černý, 1981; Breaks and Moore, 1992). Such pegmatites form from volatile-rich magmas commonly associated with post-tectonic granitic intrusions. The fluoritic Nueltin granite suite is a likely candidate from which the rare element pegmatite could have originated, and thus the boulder’s source may lie nearby to the north or northeast where several such plutons exist.
9. Acknowledgments The author wishes to extend his thanks and appreciation to all the personnel from 2001 to 2003 that helped make this project a success and for their parts in collecting the samples reviewed in this paper. Thanks to Ralf Maxeiner and Colin Card for their careful edit of the paper.
10. References Aspler, L.B. and Chiarenzelli, J.R. (1996): Stratigraphy, sedimentology and physical volcanology of the Henik
Group, Central Ennadai-Rankin greenstone belt, Northwest Territories, Canada: Late Archean paleogeography of the Hearne Province and tectonic implications; Precamb. Resear., v77, p59-89.
Breaks, F.W. and Moore Jr., J.M. (1992): The Ghost lake Batholith, Superior Province of northwestern Ontario: A fertile, S-type, peraluminous granite–rare-element pegmatite system; Can. Mineral., v30, p835-875.
Cabanis, B. and Lecolle, M. (1989): Le diagramme La/10-Y/15-Nb/8: un outil pour la discrimination des series volcanicques et la mise en evidence des processus del melange et/ou de conatmanination crustale; C.R. Acad. Sci. Ser. II, v309, p2023-2029.
Campbell, J.E. (2001): Phelps Lake Project: Highlights of the Quaternary investigations in the Bonokoski Lake area (NTS 64M-11, -12, -13, and -14); in Summary of Investigations 2001, Volume 2, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2001-4.2, CD-ROM, p19-27.
Chiarenzelli, J.R. and Macdonald, R. (1986): A U-Pb zircon date for the Ennadai Group; in Summary of Investigations 1986, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 86-4, p112-113.
Coulson, I.M. (2002): The Geology of the Archean Ennadai Greenstone Belt, McLintock Lake Area (Part of NTS 64M-13), Northeast Saskatchewan; unpubl. report prepared for Sask. Energy Mines, 30p.
Coulson, I.M., Kraus, J., Harper, C.T., and Shives, R.B.K. (2001): Some aspects on the geology of the Archean Ennadai–Rankin Greenstone Belt, northeast Saskatchewan; in Summary of Investigations 2001, Volume 2, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2001-4.2, CD-ROM, p43-49.
Davis, W.J., Hanmer, S., Aspler, L., Sandeman, S., Tella, S., Zaleski, E., Relf, C., Ryan, J., Berman, R., and MacLachlan, K. (2000): Regional differences in the Neoarchean crustal evolution of the Western Churchill Province: Can we make sense of it?; GeoCanada 2000, Calgary, May 29 to June 2, conference CD-ROM, abstr. #864.
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Drummond, M.S., Defant, M.J., and Kepezhinskas, P.K. (1996): Petrogenesis of slab-derived trondhjemite-tonalite-dacite/adakite magmas; Trans. Roy. Soc. Edinburgh, v87, p205-215.
Frost, B.R., Barnes, C.G., Collins, W.J., Arculus, R.J., Ellis, D.J., and Frost, C.D. (2001): A geochemical classification for granitic rocks; J. Petrol., v42, p2033-2048.
Goad, B.E. and Černý, P. (1981): Peraluminous pegmatitic granites and their pegmatite aureoles in the Winnipeg River district, southeastern Manitoba; Can. Mineral., v19, p177-194.
Hanmer, S. (1997): Geology of the Striding-Athabasca Mylonite Zone, northern Saskatchewan and southeastern District of Mackenzie, Northwest Territories; Geol. Surv. Can., Bull. 501, 92p.
Hanmer, S. and Kopf, C. (1993): The Snowbird tectonic zone in District of Mackenzie, Northwest Territories; in Current Research, Part C, Canadian Shield, Geol. Surv. Can., Pap. 93-1C, p41-52.
Harper, C.T., Campbell, J.E., and MacDougall, D.G. (2002b): Phelps Lake Project: Rock and till geochemistry of the Bonokoski Lake area (NTS 64M-NW) and mineral occurrence geochemistry of Phelps Lake area (NTS 64M); Sask. Industry Resources, Data File 21, 1p and 1diskette.
Harper, C.T., Heaman, L.M., Hartlaub, R.P., and Wodicka, N. (2004): New Geochronological Constraints on the Precambrian history of the Hearne Province, Northeast Saskatchewan; Geol. Assoc. Can./Mineral. Assoc. Can, Jt. Annu. Meet., St. Catharines, May 12 to 14, Abstr. #GS07-04.
Harper, C.T., Kraus, J., Demmans, C.J., Huebert, C., Coulson, I.M., and Rainville, S. (2001): Phelps lake Project: Geology and mineral potential of the Bonokoski Lake area (NTS 64M-11, -12, -13, and -14); in Summary of Investigations 2001, Volume 2, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2001-4.2, CD-ROM, p3-18.
Harper, C.T., Savage, D., and Bailey, K. (2003): Phelps Lake Project: Geology of the Misaw Lake area (part of 64M-NE) and compilation mapping in the south half of the Phelps Lake sheet; in Summary of Investigations 2003, Volume 2, Saskatchewan Geological Survey, Sask. Industry Resources, Misc. Rep. 2003-4.2, CD-ROM, Paper A-4, 17p.
Harper, C.T., Wolbaum, R.J., Thain, S., Senkow, M., Weber, D., Gunning, M., and MacLachlan, K. (2002a): Phelps Lake Project: Geology and mineral potential of the Keseechewun Lake–Many Islands Lake area (parts of NTS 64M-9, -10, -15, and -16); in Summary of Investigations 2002, Volume 2, Saskatchewan Geological Survey, Sask. Industry Resources, Misc. Rep. 2002-4.2, CD-ROM, Paper A-1, 18p.
Heaman, L.M., Hartlaub, R.P., Ashton, K.E., Harper, C.T., and Maxeiner, R.O. (2003): Preliminary results of the 2002-2003 Saskatchewan Industry and Resources Geochronology Program; in Summary of Investigations 2003, Volume 2, Saskatchewan Geological Survey, Sask. Industry Resources, Misc. Rep. 2003-4.2, CD-ROM, Paper A-3, 4p.
Jensen, L.S. (1976): A new cation plot for classifying subalkalic volcanic rocks; Ont. Geol. Surv., Misc. Pap. 66, 22p.
London, D. (1992): The application of experimental petrology to the genesis and crystallization of granitic pegmatites; Can. Mineral., v30, p499-540.
Macdonald, R. (1984): Notes on the Ennadai Group; in Summary of Investigations 1984, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 84-4, p76-77.
MacDougall, D.G. (2001): Metallogeny of mineral occurrences in the Phelps Lake region (NTS 64M); ); in Summary of Investigations 2001, Volume 2, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2001-4.2, CD-ROM, p28-42.
__________ (2002): Rare earth element and other mineral occurrences in the Phelps Lake region (NTS 64M); in Summary of Investigations 2002, Volume 2, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 2002-4.2, CD-ROM, Pap. B-1, 23p.
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Martin, H. and Moyen, J-F. (2002): Secular changes in tonalite-trondhjemite-granodiorite composition as markers of the progressive cooling of Earth; Geol., v30, no4, p319-322.
Meschede, M. (1986): A method of discriminating between different types of mid-ocean ridge basalts and continental tholeiites with the Nb-Zr-Y diagram; Chem. Geol., v56, p207-218.
Orrell, S.E., Bickford, M.E., and Lewry, J.F. (1999): Crustal evolution and age of thermotectonic reworking in the western hinterland of the Trans-Hudson Orogen, northern Saskatchewan; Precamb. Resear., v95, p187-223.
Pearce, J.A. (1996): A user’s guide to basalt discrimination diagrams; in Wyman, D.A. (ed.), Trace element geochemistry of volcanic rocks: Applications for massive sulphide exploration; Geol. Assoc. Can., Short Course Notes, v12, p79-113.
Pearce, J.A., Lippard, S.J., and Roberts, S. (1984): Characteristics and tectonic significance of suprasubduction zone ophiolites; in Kokelaar, B.P. and Howells, M.F. (eds.), Marginal Basin Geology, Blackwell Scientific Publications, Oxford, Geol. Soc. London, Spec. Publ. 81, p53-75.
Peter, J.M. (2003): Ancient iron formations: Their genesis and use in the exploration for stratiform base metal sulphide deposits, with examples from the Bathurst Mining Camp; in Lentz, D.R. (ed.), Geochemistry of Sediments and Sedimentary Rocks: Evolutionary Considerations to Mineral Deposit-forming Environments, Geol. Assoc. Can., GeoText 4, p145-176.
Peterson, T.D. and Lee, C. (1995): Pre-Dubawnt plutonism and deformation in the Nicholson Lake–Dubawnt Lake area, Northwest Territories; in Current Research, Canadian Shield, Geol. Surv. Can., 1995-C, p11-18.
Peterson, T.D. and van Breemen, O. (1999): Review and progress report of Proterozoic granitoid rocks of the western Churchill Province, Northwest Territories (Nunavut); in Current Research, Canadian Shield, Geol. Surv. Can., 1999-C, p119-127.
Peterson, T.D., van Breemen, O., Sandeman, H.A., and Cousens, B. (2002): Proterozoic (1.85-1.75 Ga) igneous suites of the Western Churchill Province: Granitoid and ultrapotassic magmatism in a reworked Archean hinterland; Precamb. Resear., v119, p73-100.
Peterson, T.D., van Breemen, O., Sandeman, H.A., and Rainbird, R.H. (2000): Proterozoic (1.85-1.75 Ga) granitoid plutonism and tectonics of the Western Churchill Province; GeoCanada 2000, Calgary, May 29 to June 2, conference CD-ROM, abstr. #539.
Rainville, S. (2002): Geochemical investigation and geological mapping of possible Ennadai-Rankin metavolcanic rocks in the Bonokoski Lake area, northeastern Saskatchewan; unpubl. B.Sc. thesis, Univ. Regina, 52p.
Rainville, S., Harper, C.T., Watters, B., and Coulson, I.M. (2002): Petrology and lithogeochemistry of mafic metavolcanic rocks at Bonokoski Lake, northwestern Hearne Province, northeast Saskatchewan: Probable equivalents of the Ennadai-Rankin Greenstone Belt; Geol. Assoc. Can./Miner. Assoc. Can., Jt. Annu. Meet., Saskatoon, May 27 to 29, Abstr. Vol. 27, p95.
Reilly, B.A. (1989): Bedrock geological mapping, Hatle Lake area (part of NTS 64M-13 and -14); in Summary of Investigations 1989, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep. 89-4, p11-16.
__________ (1993): Bedrock geological mapping, Hatle Lake area (part of NTS 64M-13 and -14); Sask. Energy Mines, Open File Rep. 93-2, 21p.
Sandeman, H., Davis, W., Hanmer, S., MacLachlan, K., Peterson, T., Ryan. J., Tella, S., Cousens, B., and Relf, C. (2000): Geochemistry of Neoarchean plutonic rocks of the Hearne Domain, Western Churchill Province, Nunavut: Granitoids associated with the formation and stabilization of “arc-like” oceanic crust; GeoCanada 2000,Calgary, May 29 to June 2, conference CD-ROM, abstr. #810.
Selbekk, R.S. and Skjerlie, K.P. (2000): Tonalite magma formation in island arcs by anatexis in the presence of subducted seawater: Ordovician analogue of Archean tonalites?; Fall Meeting 2000, Eos Trans., AGU, 81(48), abstr. V72B-03.
Senkow, M.D. (2003): Investigation of a presumed rhodochrosite occurrence in Hurwitz Group carbonate rocks, Many Islands Lake area, northeast Saskatchewan; unpubl. B.Sc. thesis, Univ. Regina, 40p.
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Shearer, C.K., Papike, J.J., and Jolliff, B.L. (1992): Petrogenetic links among granites in the Harney Peak rare-element granite–pegmatite system, Black Hills, South Dakota; Can. Mineral., v30, p785-809.
Sillitoe, R.H. (1996): Granites and metal deposits; Episodes, v19, p126-133.
Smithies, R.H. and Champion, D.C. (2000): The Archean high-Mg diorite suite: Links to tonalite-trondhjemite-granodiorite magmatism and implications for Early Archean crustal growth; J. Petrol., v41, p1653-1671.
Smithies, R.H., Champion, D.C., and Cassidy, K.F. (2003): Formation of Earth’s early Archean continental crust; Precamb. Resear., v127, p89-101.
Taylor, S.R. and McLennan, S.M. (1985): The Continental Crust: Its Composition and Evolution. An Examination of the Geological Record Preserved in Sedimentary Rocks; Blackwell Publications, Oxford, 328p.
Tella, S., LeCheminant, A.N., Sanborn-Barrie, M., and Venance, K.E. (1997): Geology and structure of parts of MacQuoid Lake map area, District of Keewatin, Northwest Territories; in Current Research, Canadian Shield, Geol. Surv. Can., 1997-C, p123-132.
Williams, M.L., Jercinovic, M.J., and Terry, M.P. (1999): Age mapping and dating of monazite on the electron microprobe: Deconvoluting multistage tectonic histories; Geol., v27, p1023-1026.
Wood, D.A. (1980): The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary volcanic province; Earth Planet. Sci. Lett., v50, p11-30.
Saskatchewan Geological Survey 18 Summary of Investigations 2004, Volume 2
Appendix 1 – Analytical Techniques The following procedures were used by Activation Laboratories Ltd. (Actlabs) in processing the rock samples supplied by Saskatchewan Industry and Resources. The samples were prepared for analyses by crushing the sample to minus 10 mesh, mechanically splitting the sample and then pulverizing with mild steel to obtain at least 95% at minus 150 mesh. For research quality analyses, Actlabs uses a lithium metaborate–tetraborate fusion ICP technique for the whole rock package (major oxides plus Ba, Sr, Y, Sc, Zr, Be, and V) and for the 45 trace and rare earth element ICP-MS package (also includes Ba, Sr, Y, Zr, and V). To obtain lower detection limits for certain elements (Ag, As, Au, Bi, Br, Cd, Cr, Cu, Ir, Ni, S, Sc, Se, and Zn), some of which are not included in the standard trace element package; the analyses are done by INAA. Fluorine was done as an add-on to the above package by ISE. Lithium was analysed by ICP-MS following an aqua regia extraction. The mineralized samples listed in Appendix 6 were encapsulated, irradiated, and measured in a multielement mode by INAA for Au plus 34 trace elements at enhanced detection limits.
Every tenth sample in a submitted batch underwent a replicate analysis. In addition, internal Actlabs standards were run with each batch and those values included along with the accepted values with each report. The accuracy of analyses was consistently very high.
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Appendix 2 – Geochemical Data for the Archean Migmatites and Intrusive Rocks of the Phelps Lake Region UTM Coordinates are for Zone 13, Based on NAD 83. Note: Gb, gabbro; DM, dioritic migmatite; TM, tonalitic migmatite; Tg, tonalite gneiss; GL, leucogranite gneiss; G, granite gneiss; al, allanite; n/a, not analysed; and py, pyrite; negative values are below detection limit for that element.
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Appendix 3 – Geochemistry of Ennadai Group Volcanic and Sedimentary Rocks UTM Coordinates are for Zone 13 and Based on NAD 83. Note: EVM, Ennadai mafic volcanic regional samples; EVM Bono, mafic volcanic samples from Bonokoski Lake; EVM min, weakly pyrite, pyrrhotite, ±chalcopyrite-bearing Ennadai mafic volcanic rocks, EVMminQV, with pyritic quartz veins; EVFr, Ennadai felsic (rhyolite) volcanic; ESIFo,s,k, Ennadai iron formation, oxide, sulphide, silicate facies; and n/a, not analysed; negative values are below detection limit for those elements.
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0111-CAMP 0111-CAMPR 0111-0043 0211-1124 0211-1127 0111-356 0111-4187 0311-3028 0111-341 0111-343 0111-297 0111-329 0111-330 0111-336 0111-4188 0111-4188R 0311-1020ESIF ESIF EVM min EVM min EVM min EVM min EVM min EVM min EVM min EVM min EVM min EVMminQV EVMminQV EVMminQV EVMminQV EVMminQV EVMminQV
Saskatchewan Geological Survey 22 Summary of Investigations 2004, Volume 2
Appendix 4 – Geochemistry of Hurwitz Group Rocks UTM Coordinates are for Zone 13 and Based on NAD 83. Note: HAp, Ameto Formation pelite; HApf,o,s, ferruginous pelite, oxide facies, sulphide facies; HWcs, Watterson Formation, calc-silicate rocks; HWm,qv, marble, with quartz veining; Wp, Wollaston Supergroup pelite; n/a, not analysed; negative values are below detection limits.
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Appendix 5 – Chemistry of Proterozoic Intrusive Rocks UTM Coordinates are for Zone 13 and Based on NAD 83. Note: Hud G, Hudson granite suite; Hud G(Mo), with molybdenite; Nuel G; Nueltin granite suite; Nuel G(F), fluorite bearing; Lep peg; lepidolite-bearing pegmatite; and n/a, not analysed; negative values are below detection limits.
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Appendix 6 – Iron Sulphide– and Quartz Vein–bearing Samples from the Phelps Lake Area UTM Coordinates are for Zone 13 and Based on NAD 83. Note: ESIFs, Ennadai Group sulphide facies iron formation; EVFr, Ennadai felsic volcanic (rhyolite); EVM, Ennadai mafic volcanic; bldr, boulder, po, pyrrhotite; py, pyrite; qtzite, quartzite; QV, quartz veins; negative values are below detection limits.