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80 a inclusion KL-2 and intergrowth field Summary and guide to figures 70 KL-3

In 2016, bedrock mapping and sampling by the Manitoba Geological Survey resulted Indicator in the conglomerate (MGS sample LX/KL-2) consist of chromite 60 Argyle lo Geology of diamond occurrences at southern Knee Lake, Oxford Lake–Knee Lake in the discovery of microdiamonds in shoreline outcrop at southern Knee Lake – a and Cr-spinel, whereas the lapilli tuff (MGS sample LX/KL-3) contains chromite, Cr- eo gic g a 50 a l discovery since confirmed and extended by Altius Minerals Corp. (press release, , Cr-spinel and diamond-inclusion Cr-spinel, indicative of a mantle-derived b s 2 3 u o Cr O (wt. %) September 25, 2017). The microdiamonds are hosted by polymictic volcanic magmatic precursor sourced from within the diamond stability field (>140 km 40 t r

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conglomerate and volcanic sandstone belonging to the Oxford Lake group (ca. 2.72 depth). Indicator compositions (Figures 18 & 19), coupled with the absence n

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a MGS HP y greenstone belt, Manitoba (NTS 53L14, 15) Ga) of the Oxford Lake–Knee Lake greenstone belt in the northwestern Superior of and ilmenite, suggest that the magmatic precursor was not kimberlitic. 30 province (Figures 1–5). Well-preserved primary features (Figures 6–8) indicate m 20 deposition as debris and turbidity flows in an alluvial or shallow-marine fan setting, Microdiamonds (n = 144; Figures 20 & 21) obtained from a 15.8 kg sample of the 1928 S.D. Anderson (Manitoba Geological Survey) 0 5 10 15 20 whereas interlayers of lapilli tuff (Figure 9) record influxes of pyroclastic material. volcanic conglomerate (sample LX/KL-2) are variable in colour, morphology and MgO (wt. %) 1.0 10 degree of resorption, with the largest stone weighing 0.2071 mg (0.00104 ct); a b c Whole- geochemical data (Figures 10 & 11) indicate primitive bulk compositions sample of the lapilli tuff did not yield , whereas lamprophyre dikes at Knee LIP (16.7–18.7 wt. % MgO; >500 ppm Cr, Ni) and alkaline affinities (1.2–3.3 wt. % K₂O) for Lake have yet to be assessed for diamonds or indicator minerals. 0.8 spinel OIB Y/15 the volcanic sedimentary rocks and lapilli tuff, collectively referred to as the 10 1 MORB Station: 52-97-1052 ARC 'ultramafic association', and are comparable to primitive alkaline lamprophyre Unconventional diamond occurrences hosted by lamprophyre dikes, polymict a b a b a b 0.6 NAD83 UTM 15N: 379904E, 6079883N dikes in the Knee Lake area (Figure 12), suggesting an association with lamprophyric volcaniclastic breccia and conglomerate in the Michipicoten greenstone belt (south- * Back arc NMORB OIB 2 Channel basin Major zoning TiO (wt. %) volcanism. central Superior province) near Wawa, Ontario, provide a useful analog to the cut VAT Cr/(Cr+Al) 0.4 1 trends of 0.1 occurrence at southern Knee Lake, with implications for exploration. 11413 14 * kimberlite (101) spinel Diverse clast types in the conglomerate include pyroxenite, gabbro and basalt, 0.2 EMORB Kimberlite MORB presumably derived from the ca. 2.83 Ga Hayes River group (Figure 13), representing As is the case in the Wawa area, the types and compositions of indicator minerals 11412 12 Th/Yb groundmass EMORB peridotite (88) spinel SSZ 0.01 peridotite the local basement. Distinctive cored clasts (Figure 14) in the diamondiferous hosted by the lamprophyric rocks at Knee Lake are distinctly different from those 0.1 11411 0.0 0 10 20 30 40 50 conglomerate are interpreted to represent pelletal lapilli that formed during intensive found in surficial sediments. The former are compatible with 'typical' mantle-derived (120) 10 0.0 0.2 0.4 0.6 0.8 1.0 NMORB 2+ 2+ Fe /(Fe +Mg) Al2 O 3 (wt. %) degassing within a diatreme vent and were subsequently reworked by sedimentary rocks such as komatiite or primitive arc basalt, which are major constituents of 11410 Alkaline (99) intercontinental processes. greenstone belts in the Superior province, whereas the latter are indicative of Calcalkaline rifts Figure 18: Bivariate plots for chromite and Cr-spinel grains recovered from MGS samples KL-2 8 Continental 11409 LX/KL-2 0.01 diverse sources, possibly including kimberlite. Consequently, any exploration (112) and KL-3: a) MgO vs. Cr₂O₃; fields for diamond inclusions, Argyle lamproite and HP lamprophyre (83) La/10 Nb/8 0.1 1 10 100 Multiphase ductile deformation fabrics (Figures 15 & 16), greenschist-facies strategy that employs drift prospecting will require careful consideration of not only Nb/Yb are from Fipke et al. (1995); field for kimberlite spinel is from Nowicki et al. (2007); b) 11408 Metres metamorphic assemblages, and interstratification with dacitic volcanic rocks dated at the complex surficial geology and ice-transport history in the Knee Lake region, but c d (75) 6 c d Figure 13: Trace element discrimination diagrams for clasts in conglomerate of Fe²⁺/(Fe²⁺+Mg) vs. Cr/(Cr+Al); compositional field for komatiite spinel is from Barnes and Roeder 2722 ± 3 Ma (Figures 5 & 17) confirm the Archean emplacement age, placing this also the potentially diverse and extensive sources of indicator minerals. 11407 (2001); compositional field and principal zoning trends for kimberlite groundmass spinel are from (95) the UFA (purple diamonds), shown in comparison to volcanic rocks of the diamond occurrence amongst the oldest known on Earth. 4 HRG at Oxford Lake and Knee Lake, representing the local basement during Roeder and Schulze (2008); c) Al₂O₃ vs. TiO₂ (after Kamenetsky et al., 2001). Abbreviations: ARC, 11406 (67) alkaline volcanism (green triangles; unpublished data from Syme et al., 1997, island-arc; LIP, large igneous province; OIB, ocean-island basalt; MORB, mid-ocean–ridge basalt;

2 1998; Anderson et al., 2012, 2013): a) La/10 vs. Y/15 vs. Nb/8 (Cabanis and SSZ, supra-subduction zone. Spinel compositions are consistent with typical arc volcanic rocks

6090000N 390000E Lecolle, 1989); b) Log Nb/Yb vs. Log Th/Yb (Pearce and Peate, 1995). (including lamprophyre) or komatiite. 96° 94° Paleozoic Intrusive rocks Abbreviations: EMORB, enriched mid-ocean–ridge basalt; NMORB, normal Paleoproterozoic WLP CLAIC 0 NKF Cinder Lake alkaline intrusive complex: Opischikona 5 HBT CLAIC mid-ocean–ridge basalt; OIB, ocean-island basalt; VAT, volcanic-arc tholeiite. syenite, monzogranite, pegmatite Narrows MS CS PC CC Figure 19: Bivariate plot Cinder Garnet Oxford Lake–Knee Lake Lake WLP Whitemud Lake pluton: peridotite (Al₂O₃ vs. Cr₂O₃) for Cr- greenstone belt , granite Figure 7: Simplified stratigraphic column for bedded polymictic 4 diopside grains from MGS 55° Knee Bayly Lake pluton: Lake granite / granodiorite conglomerate at the discovery outcrop in the eastern bay. Cross Oxford Serpentinite sample KL-3; compositional Lake Lake OSD Normally-graded beds are capped by pebbly sandstone, 3 Inclusion Spinel peridotite field for diamond-inclusion SWF Omusinapis Gods Point Figure 6: Outcrop photographs of diamondiferous polymictic conglomerate of the UFA: a) consistent with sedimentation from high-density turbidity Figure 12: Outcrop photographs of lamprophyre dikes at central Knee Lake: a) primitive (11 wt. % and and off-craton garnet Lake a b intergrowth peridotite and diamond-intergrowth Cr- Lake Pain Killer GF LISZ Bay AF boulder–cobble conglomerate, western bay; b) massive cobble–pebble conglomerate showing currents. Channel samples are from Altius Minerals Corp. (press MgO) lamprophyre ; b) flow-banded dike of more evolved lamprophyre (7.7 wt. % MgO); c) 2 3 diopside is from Nimis Sharpe Trout 2 Molson Lake TISZ polymictic clast population and rounded clasts, eastern bay; c) cobble–pebble conglomerate beds release, September 25, 2017), following up on the original MGS primitive (11.5 wt. % MgO) lamprophyre dike with thick chilled margins; d) coarse of Cr O (wt.%) Lake (2002); other compositional at the discovery outcrop (MGS sample LX/KL-2 locality) showing size grading and deeply scoured sample (LX/KL-2). Numbers in parentheses indicate diamond in primitive lamprophyre dike (same locality as previous photo). 54° Long Trout Opawakow Island Eclogite, fields are from Ramsay and NCT Falls Narrows basal contacts, eastern bay; d) detail of graded bed of polymictic conglomerate, discovery megacryst 0 5 counts in the +0.106 mm size fractions (note higher counts in 1 Tompkins (1994). Celtic and cognate Taskipochikay Knee Kilometres outcrop, eastern bay. sandy beds). Abbreviations: CC, cobble conglomerate; CS, coarse- Hayes Opapuskitew Island Island Bay GF Lake LISZ Lake River grained sandstone; MS, medium-grained sandstone; PC, pebble AF Diamond occurrence 0 F2 Lake showing conglomerate. 0 2 4 6 8 10 12 14 Winnipeg F 2 Fold axial trace a Al2 O 3 (wt.%) 50 Manitoba b kilometres Ontario Shear zone, fault F1 F S0 1 Younging direction Michikanes a b Lake TISZ Figure 1: Regional geological setting of the Oxford Geological contact 363000E 6075000N RU a Lake–Knee Lake greenstone belt in the northwestern Oxford Lake group Hayes River group Superior province (terminology after Stott et al., 2010). Synorogenic sedimentary rocks Volcanic subgroup Intermediate–felsic intrusive rocks; c d - Significant gold deposits are indicated by red circles. Greywacke, quartz greywacke Volcanic sedimentary rocks Volcanic conglomerate, greywacke Ultramafic–mafic sills S Abbreviations: HBT, Hudson Bay terrane; NCT, North 0 Volcanic, volcaniclastic and volcanic Volcanic conglomerate, greywacke S sedimentary rocks 1 Caribou terrane; NKF, North Kenyon fault; OSD, Sedimentary subgroup Felsic volcanic and volcaniclastic rocks J LS Oxford–Stull domain; SWF, Stull-Wunnummin fault. Arkosic quartz-greywacke, mudstone Andesitic–dacitic facies association Mafic volcanic rocks (flows): Polymictic conglomerate, greywacke, Basaltic andesite facies association aphyric / amphibolitic Location of Figure 2 is outlined. mudstone, iron formation Ultramafic facies association variolitic / porphyritic F2 L Figure 2: Simplified geology of southern Knee Lake (after Anderson et al., 2015a), including 2 diamond occurrences reported by Anderson (2017b) and Altius Minerals Corp. (press release, b c d 0.5 mm a b September 25, 2017). Geology outside the mapping limit is simplified from Gilbert (1985) and c d high-resolution aeromagnetic data. Hachure pattern indicates undivided tectonite. Abbreviations: Figure 20: Microdiamonds (MD) recovered from MGS sample LX-2: a) MD from the +0.425 mm AF and GF indicate structural boundaries between facies and greenschist facies size fraction, showing minor inclusions; b) examples of clear, colourless MD from the +0.212 rocks; LISZ, Long Island shear zone; TISZ, Taskipochikay Island shear zone. Location of Figure 3 is e f mm size fraction. outlined.

0.2500 10000 6080969N n = 144 a b LISZ Figure 3: Simplified geology 0.2000 Knee LX/KL-2 of southeastern Knee Lake 1000

371537E Lake Y showing the distribution of 0.1500 Knee Y Figure 9: Outcrop photographs of lapilli tuff (MGS sample LX/KL-3 locality) in the 100 Lake the ultramafic facies Figure 14: Outcrop photographs of pelletal lapilli from diamondiferous conglomerate in the

Y Y western bay: a) -supported lapilli tuff showing the essentially monolithic character 0.1000 Y association (UFA) and the eastern bay: a) pebble conglomerate bed containing abundant pelletal lapilli (arrows); b) pelletal Y Figure 8: Outcrop photographs of sandstone in the UFA: a) pebbly sandstone showing scour-and- (gabbro clast indicated by arrow); b) detail of lapillus showing ragged margin and 10

2722 ±3 Ma locations of the western 0.0500 Y lapilli (arrow) and dark green clasts of juvenile lithic material (J); c) detail of lapillus (dashed

fill channel at the base and convolute bedding at the top, eastern bay; b) turbiditic sandstone and Microdiamond weight (mg) Y and eastern bays (type vesicular texture. Figure 5 ‘eastern outline), showing serpentinite core and lithic rim; d) large lapillus showing thin continuous rim of mudstone, showing normal size-grading (black arrow), load structures (LS), ripples (arrow) and 0.0000 Number of microdiamonds/Tonne bay’ localities of the UFA). Also dark green lithic material around a pyroxenite core. 1 mudstone rip-ups (RU), western bay; bedding is overturned in this location; pencil points north; 0 25 50 75 100 0.1 1 shown are the locations of Figure 15: Outcrop photographs of deformation structures at southern Knee Lake, based on the Square Mesh Sieve Size (mm) LX/KL-3 Cumulative percentile TaskipochikayTaskipochikay c) normally-graded sandstone bed with contorted rip-ups of mudstone, eastern bay; d) diffuse a b deformation sequence of Anderson et al. (2015b) and Anderson (2016): a) isoclinal F₁ fold, Island MGS samples LX/KL-2 and Island ‘western compound size-grading and cross-bedding in pebbly sandstone and conglomerate, eastern bay. 100 defined by iron formation in greywacke ('S₀' indicates bedding), overprinted by F₂ folds (axial Figure 21: Distribution plots for microdiamonds (MD) from MGS sample LX-2 (15.8 kg): a) bay’ LX/KL-3, and diamond 100 occurrences reported by Eastern Bay Western Bay planes are indicated by dashed lines); b) steep L₂ stretching lineation in conglomerate; prolate cumulative percentile plot of MD size by weight, showing a continuous distribution up to the 95th Figure 4 fabric indicated by aspect ratios of clasts on the horizontal and vertical outcrop faces; c) bedding- Altius Minerals Corp. Bedding, upright (n = 12) Bedding, upright (n = 2) percentile; b) square-mesh sieve size vs. number of MD/tonne (log-log) showing a linear, relatively a TISZ Bedding, tops unknown (n = 10) b Bedding, overturned (n = 3) parallel S₁ foliation and isoclinal F₂ fold in the UFA, western bay; d) vertical outcrop face showing 382259E steep distribution curve for sample LX-2 (blue line; dashed line indicates best-fit); shown for 0 2 10 Macroscopic fold axis (n = 1) Bedding, tops unknown (n = 2) Rock/Chondrites 10 6 30 Intersection lineation (n = 2) steep stretching lineation (L₂) at a high-angle to bedding in the hinge of a mesoscopic F₂ fold in comparison purposes are MD distribution curves (grey lines) for samples of resedimented Locations of Figure 4 and Rock/Primitive Mantle kilometres a Basalt Basaltic- Andesite Dacite the UFA, western bay; e) shallow-plunging L₄ stretching lineation defined by deformed clasts in Figure 5 are outlined. 5 andesite b volcaniclastic kimberlite from the Misery complex of the Ekati mine (Krebs et al., 2016); data from a 6076444N Shoshonitic series volcanic conglomerate; f) mylonitic S₄ foliation and F₄ Z-folds in the Long Island shear zone continuous channel sample (12.9 m, 128kg) collected by Altius Minerals Corp. (press release, Oxford Lake group Hayes River group 4 20 1 1 (asymmetric quartz boudins indicate dextral shear). September 25, 2017; see Figure 7 for channel location) across the discovery outcrop is indicated by High-K calcalkaline series Volcanic sedimentary rocks Mafic volcanic rocks the orange line (dashed line indicates best-fit); the conglomerate shows high concentrations of MD 3 c d

Volcanic conglomerate, greywacke 2 in the smaller size fractions, whereas the steep slopes of the best-fit lines suggest that the 100 Y K O (wt. %) MgO (wt. %) 2 10 100 maximum stone size is likely to be ~2 mm. Volcanic, volcaniclastic and volcanic Younging direction Calcalkaline series sedimentary rocks Geological contact 1 a b Tholeiite series Andesitic–dacitic facies association Fold axial trace 10 Foliation (n = 14) Foliation (n = 6) 0 0 Rock/Chondrites 10 Stretching lineation (n = 2) c d Stretching lineation (n = 4)

40 50 60 70 40 50 60 70 Rock/Primitive Mantle Exploration implications (syncline, anticline) Shear zone, dextral (n = 6) Shear zone, dextral (n = 8) SiO2 (wt. %) SiO2 (wt. %) Basaltic andesite facies association 10000 100 Shear zone, stretching lineation (n = 6) Fault, shear zone The southern Knee Lake microdiamond occurrence represents the first discovery of diamonds Ultramafic facies association c d Mapping limit 1 1 associated with alkaline volcanic rocks in Manitoba. 10 e f

cn Although diamonds are typically hosted by kimberlite intrusions (e.g., Kjarsgaard, 2007), 100 6080500N 381500E 1000 100 significant deposits and occurrences are also associated with other types of mantle-derived

LISZ (La/Yb) Cr+Ni (ppm) 1 intrusions, including lamproite and ultramafic lamprophyre, and calcalkaline lamprophyre (e.g., 1 Fault-bounded wedge Gurney et al., 2005). Examples of the latter association in the Michipicoten belt near Wawa, of Hayes River group 2 3 6078700mN 10 Rock/Chondrites 10 Ontario (Lefebvre et al., 2005), are strongly analogous to the Knee Lake diamond occurrence and ‘western bay’ Rock/Primitive Mantle Figure 16: Lower-hemisphere, equal-angle stereographic projections of structural data c provide insight into the potential complexity of these systems, with relevance to exploration (Knee Lake) Contact 100 0.1 d 40 50 60 70 40 50 60 70

LISZ 377800mE from the UFA: a) poles to bedding in the eastern bay; star represents pole to girdle Knee 5 methodologies. SiO2 (wt. %) SiO (wt. %) 4 Shear zone 2 (dashed line) defined by bedding orientations and indicates the plunge of a Lake LX/KL-3 1 1 Figure 10: Whole-rock geochemical data for various components of the UFA La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Nb La Ce Pr Nd Zr Sm Eu Ti Dy Y Yb Lu macroscopic F₂ fold (star); b) poles to bedding (S₀) in the western bay; stars indicate As in the Michipicoten belt, discontinuous exposure and complex structure at Knee Lake hinder 0 1000 (sandstone, blue squares; lapilli tuff, green triangle; clasts in conglomerate, purple DVC Gabbro, pyroxenite Figure 11: Chondrite and primitive mantle–normalized trace-element diagrams for measured S₀-S₂ intersection lineations, corresponding to mesoscopic F₂ fold hinges; c) stratigraphic correlations of diamondiferous units. In addition, the type and chemistry of metres diamonds), including for comparison purposes examples of primitive lamprophyre the various components of the UFA, including for comparison purposes examples of L₂ lineation and poles to planar fabrics (foliation is S₂; shear zones are S₄) in the indicator minerals obtained from the diamondiferous rocks differ significantly from those Gold occurrence Volcanic sandstone, mudstone, 6 Oxford Lake group Porphyritic dikes from Oxford Lake and Knee Lake (red circles; grey tie-lines indicate the most lamprophyre dikes from Oxford Lake and Knee Lake (symbols as in Figure 10); a) and eastern bay; d) L₂ (steep) and L₄ (shallow) lineations and poles to planar fabrics Quartz-tourmaline veins or alteration andesite lapilli tuff (UFA) recovered from surficial sediments (e.g., Fedikow et al., 2002), indicating derivation from Andesitic–dacitic facies association (calcalkalic) primitive dikes); a) SiO₂ vs. K₂O; fields for shoshonitic, high-K calcalkaline, calcalkaline Ankerite veins or alteration b) sandstone and lapilli tuff; c) and d) clasts in conglomerate (different coloured tie- (foliation is S₂; shear zones are S₄) in the western bay. different sources. At Knee Lake, drift prospecting is further complicated by a number of factors, Volcanic conglomerate, sandstone, Quartz-feldspar porphyry dike Volcanic conglomerate, and mudstone sandstone (UFA) and tholeiitic series are from Peccerillo and Taylor (1976); b) SiO₂ vs. MgO; c) SiO₂ vs. lines indicate the three different profiles evident in this sample set); e) and f) Microdiamond occurrence including several directions of ice flow, widespread dilution of the local bedrock signature by far- Dacitic fragmental rocks Dacitic tuff and tuff breccia sum of Cr+Ni; d) SiO₂ vs. (La/Yb)cn (cn, chondrite normalized; values of Sun and lamprophyre dikes (grey tie-lines indicate the most primitive dikes). Normalizing Andesitic flows and fragmental rocks Stratigraphic younging Heterolithic pebble travelled calcareous till, streamlined landforms that do not reflect the ice-flow transport 8 Basaltic andesite facies association (shoshonitic) conglomerate McDonough, 1989). Diagrams illustrate the compositional similarity of the volcanic values are from Sun and McDonough (1989). Fold axial trace (F2 ) direction, and a locally thick blanket of glaciolacustrine clay (Trommelen, 2015). 0 200 Volcanic conglomerate, sandstone, mudstone, Shear zone/fault sandstone, lapilli tuff and the primitive lamprophyre dikes. iron formation and porphyritic flows Andesitic–dacitic facies 7 Bedding trendline Metres Ultramafic facies association (lamprophyric) 376900mE association Contact 6077900mN Figure 17: Outcrop photographs of dacitic volcanic conglomerate (DVC; ca. 2722 Ma; Corkery et For these reasons, the initial stages of follow-up exploration should focus on detailed mapping 9 Volcanic conglomerate, sandstone, Iron formation TISZ mudstone and lapilli tuff al., 2000) interstratified with the UFA in the western bay: a) massive to crudely stratified, clast- of volcaniclastic, sedimentary and intrusive rocks of the ultramafic facies association, and the Figure 5: Detailed map of the western bay (Anderson, 2017b) showing thick References Kamenetsky, V.S., Crawford, A.J. and Meffre, S. 2001: Journal of Petrology, v. 42, p. 655–671. 376500E 6077500N Hayes River group Anderson, S.D. 2016: Report of Activities 2016, Manitoba Geological Survey, p. 1–15. Kjarsgaard, B.A. 2007: Geological Association of Canada, Mineral Deposits Division, Special Publication No. 5, p. 245–272. Acknowledgments supported DVC; b) sharp basal contact of DVC (top), showing mudstone rip-ups derived from the collection of well-constrained bedrock samples for caustic fusion and heavy mineral separation Aphyric basaltic fragmental rocks, QFP and basalt dikes lenses of dacitic volcanic conglomerate (DVC) of the andesitic–dacitic facies Anderson, S.D. 2017a: Report of Activities 2017, Manitoba Geological Survey, p. 1–11. Krebs, M.Y., Pearson, D.G., Stachel, T., Stern, R.A., Nowicki, T. and Cairns, S. 2016: Economic Geology, v. 111, p. 503–525. Anderson, S.D. 2017b: Manitoba Geological Survey, Open File Report OF2017-3, 27 p. Lefebvre, N., Kopylova, M. and Kivi, K. 2005: Precambrian Research, v. 138, p. 57–87. underlying UFA (bottom); c) DVC containing a large angular block of pebble conglomerate (below in order to establish the spatial distribution of diamondiferous rocks and the nature of their Aphyric basaltic flows, gabbro and quartz diorite association (2722 Ma; Corkery et al., 2000) interstratified with the ultramafic Anderson, S.D., Kremer, P.D. and Martins, T. 2012: Report of Activities 2012, Manitoba Geological Survey, p. 6–22. Nimis, P. 2002: The Canadian Mineralogist, v. 40, p. 871–884. J. Deyholos, D. Downie and M. Stocking (University of Manitoba) provided capable and enthusiastic indicator mineral populations. In addition, an orientation survey of surficial sediments inland facies association (UFA). Diamond occurrence as reported by Altius Minerals Anderson, S.D., Kremer, P.D. and Martins, T. 2013: Report of Activities 2013, Manitoba Geological Survey, p. 7–22. Nowicki, T.E., Moore, R.O., Gurney, J.J. and Baumgartner, M.C. 2007: Developments in Sedimentology, v. 58, p. 1235–1267. hammer) derived from the UFA; d) thin lens of DVC interstratified with the UFA. Figure 4: Revised geology of the southeastern portion of southern Knee Lake (Anderson, Anderson, S.D., Syme, E.C., Corkery, M.T., Bailes, A.H. and Lin, S. 2015a: Manitoba Geological Survey, Preliminary Map PMAP2015-1, 1:20 000 scale. Pearce, J.A. and Peate, D.W. 1995: Annual Review of Earth and Planetary Sciences, v. 23, p. 251–285. assistance during the field mapping component of this study. The author benefited from from the eastern and western bays, including detailed characterization of the glacial till as per Corp. Anderson, S.D., Syme, E.C., Corkery, M.T., Bailes, A.H. and Lin, S. 2015b: Report of Activities 2015, Manitoba Geological Survey, p. 9–23. Peccerillo, A. and Taylor, S.R. 1976: Contribution to and Petrology, v. 58, p. 63–81. 2017a). Numbers (1–9) indicate major, fault-bounded, lithostructural panels. Barnes, S.J. and Roeder, P.L. 2001: Journal of Petrology, v. 42, p. 2279–2302. Ramsay, R.R. and Tompkins, L.A. 1994: Proceedings of the 5th International Kimberlite Conference, Araxá, Brazil, Special Publication, v. 2, p. 329–345. discussions with R. Syme, T. Corkery and A. Chakhmouradian, and C. Böhm provided a thorough the recommendations of Trommelen (2015), as well as conventional geochemical analysis for Cabanis, B. and Lecolle, M. 1989: Comptes Rendus de l'Academie des Sciences, v. 309, p. 2023–2029. Roeder, P.L. and Schulze, D.J. 2008: Journal of Petrology, v. 49, p. 1473–1495. Abbreviations: LISZ, Long Island shear zone; QFP, quartz-feldspar porphyry; TISZ, Corkery, M.T., Cameron, H.D.M., Lin, S., Skulski, T., Whalen, J.B. and Stern, R.A. 2000: Report of Activities 2000, Manitoba Geological Survey, p. 129–136. Stott, G.M., Corkery, M.T., Percival, J.A., Simard, M. and Goutier, J. 2010: Ontario Geological Survey, Open File Report 6260, p. 20-1–20-10. review of the manuscript. Mineral separation and analysis (microdiamonds and indicator minerals) elements known to be enriched in the diamondiferous rocks (e.g., Ba, Cr, Ni, Sr), may also prove Fedikow, M.A.F., Nielsen, E., Conley, G.G. and Lenton, P.G. 2002: Manitoba Geological Survey, Open File Report OF2002-1. Sun, S-s. and McDonough, W.F. 1989: Geological Society of London, Special Publications, v. 42, p. 313–345. Taskipochikay Island shear zone. Microdiamonds have been recovered from the ultramafic Fipke, C.E., Gurney, J.J. and Moore, R.O. 1995: Geological Survey of Canada, Bulletin 423, 86 p. Syme, E.C., Corkery, M.T., Bailes, A.H., Lin, S., Cameron, H.D.M. and Prouse, D. 1997: Report of Activities, 1997, Geological Services, p. 37–46. was funded by Mount Morgan Resources Ltd. (M. Fedikow), Polaris Capital Ltd. (R. Day), Indicator valuable. Gilbert, H.P. 1985: Geological Services, Geological Report GR83-1B, 76 p. Syme, E.C., Corkery, M.T., Lin, S., Skulski, T. and Jiang, D. 1998: Report of Activities, 1998, Geological Services, p. 88–95. Explorations Ltd. (J. Lee) and H. Westdal. facies association in panels 2 and 7. Gurney, J.J., Helmstaedt, H.H., Le Roex, A.P., Nowicki, T.E., Richardson, S.H. and Westerlund, K.J. 2005: Economic Geology 100th Anniversary Volume, p. 143–177. Trommelen, M.S. 2015: Manitoba Geological Survey, Geoscientific Paper GP2013-3, 30 p. plus 13 appendices.