Geology, geochronology, lithogeochemistry and metamorphism of the Holberg-Winter Harbour area, northern Graham Nixon, Hammack Jean, Fabrice Cordey

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Graham Nixon, Hammack Jean, Fabrice Cordey. Geology, geochronology, lithogeochemistry and metamorphism of the Holberg-Winter Harbour area, northern Vancouver Island. Geology, geochronol- ogy, lithogeochemistry and metamorphism of the Holberg-Winter Harbour area, northern Vancouver Island, 2011. ￿hal-03275126￿

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47 48 49 550000E 51 52 53 54 55 56 57 58 59 560000E 61 62 63 64 65 66 67 68 69 570000E 71 72 73 74 75 76 77 78 79 580000E 81 82 83 84 85 86 87 88 89 590000E 91 92 GEOSCIENCE MAP 2011-1 Jepther Cape Point Sutil Geology, Geochronology, Lithogeochemistry and Metamorphism 36 36 Weser Island of the Holberg-Winter Harbour Area, Northern Vancouver Island Parts of NTS 092L/05, 12, 13; 102I/08, 09 & 16 35 35 Lemon Loquillilla S kinne Point Cove G.T. Nixon, J.L. Hammack, V.M. Koyanagi, L.D. Snyder, G.J. Payie, A. Panteleyev, N.W.D. Massey, J.V. Hamilton, A.J. Orr, r R.M. Friedman, D.A. Archibald, J.W. Haggart, M.J. Orchard, E.T. Tozer, H.W. Tipper, T.P. Poulton, J. Palfy and F. Cordey 34 34 Creek Heimra Lake 48 PALEONTOLOGY GEOLOGY GEOCHRONOLOGY Irony 39 by by by Creek 32 Gorotisa J.W. HAGGART, M.J. ORCHARD, E.T. TOZER, H.W. TIPPER G.T. NIXON, J.L. HAMMACK, L.D. SNYDER, V.M. KOYANAGI, G.J. PAYIE, R.M. FRIEDMAN (The University of ) 33 Shuttleworth 33 Point and T.P. POULTON (Geological Survey of Canada) A. PANTELEYEV, N.W.D. MASSEY, J.V. HAMILTON and A.J. ORR D.A. ARCHIBALD (Queen's University) Bight J. PALFY (Hungarian Natural History Museum) (BC Geological Survey) F. CORDEY (University of Lyon) D.A. ARCHIBALD (Queen's University) 32 J.W. HAGGART (Geological Survey of Canada) k 32 e Christensen re Point C 0 24 ek re 31 C 31 kilometres

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N INTRUSIVE ROCKS 5630000N LAYERED ROCKS LAYERED ROCKS (Cont'd) U r s i e UPPER CRETACEOUS Lower Jurassic (Hettangian to Sinemurian) LOWER TO MIDDLE JURASSIC (ca. 197.5 to 169.9 Ma) 29 PEGATTEM CREEK SILTSTONE Phyl 29 QUEEN CHARLOTTE GROUP EQUIVALENTS (IN PART) ISLAND PLUTONIC SUITE S Dark grey-green to pale pinkish grey, medium to coarse-grained, equigranular h Cenomanian or Lower Turonian to ?Santonian Dark grey to greenish grey, fossiliferous siltstone and mudstone with minor shaley L C u lJPCs a r sh mudstone; possibly also occurs north of the Holberg-Stranby River fault system granitoid rocks and porphyry; includes gabbro (gb), hornblende±biotite-bearing u e a Lake JI r e r BLUMBERG FORMATION a k t diorite (di), quartz diorite (qdi), granodiorite (gd), plagioclase±hornblende Nissen Bight ie Massive to thinly bedded lithic to arkosic wacke with minor pebble to Upper Triassic (Rhaetian) to possibly Lower Jurassic (Hettangian) porphyry (po) and quartz-plagioclase±biotite porphyry (qpo); combined codes 28 28 indicate a range of common rock types (qdi-gd, quartz diorite - granodiorite) D uKBsn cobble conglomerate a L Phyl Creek Fisherman k ak VOLCANICLASTIC-SEDIMENTARY UNIT o Ursie e t Bay a Lake Interbedded volcaniclastic and sedimentary strata (predominantly submarine): Minor Intrusions TrJBvs Erma uKBcg Massive conglomerate with minor lenses of coarse-grained lithic wacke buff to grey-green, thin to very thickly bedded, calcareous to non-calcareous, volcanic 27 G breccia, lithic and feldspathic wacke, siltstone and limestone, locally coralline; lithic- TERTIARY k 27 C o e Lake r d e crystal tuff, lapilli tuff and reworked equivalents; and minor vitric tuff, pebbly sandstone, e k r Dark to pale grey, rhyolitic dike/sill; plagioclase±hornblende±quartz-phyric; e i k n C Cenomanian to ?Turonian siltstone, and volcaniclastic debris-flow deposits; may include black carbonaceous Tif possibly coeval with Alert Bay volcanic unit C shale, mudstone, siltstone and limestone (locally coralline) equivalent to unit TrJY in re e k SHALE UNIT the Mahatta - Alice Lake area (Geoscience Maps 2011-3 and 2011-4) C 26 re Quartz-feldspar-biotite porphyry; north of the map area e 17 a 26 k m Tipo at Christensen Point r Dark grey, calcareous to non-calcareous siltstone and impure limestone Upper Triassic (Carnian to Rhaetian) E uKs interbedded with subordinate wacke and minor pebble conglomerate (exposure restricted to the north shore of Sound) PARSON BAY FORMATION Medium grey to black, thinly laminated to medium bedded, impure limestone, EARLY(?) JURASSIC 25 Cenomanian? uTrP Godkin 25 calcareous to non-calcareous mudstone, siltstone and shale intercalated with Dark grey-green diabase to medium-grained gabbro sill; coeval 32 variable proportions of grey-green lithic feldspathic/tuffaceous wacke, minor JBid Ra Lake Lake Dark grey to grey-green and brownish grey siltstone, shale and greywacke; with Bonanza Group volcanism; dp, plagioclase porphyritic variety ne crystal-lithic tuff and reworked equivalents, volcaniclastic breccia and debris- ll uKQs locally fossiliferous of the flow deposits, and rare vitric tuff, pebbly sandstone and conglomerate; 36 Mountains shale locally yields abundant thin-shelled bivalves (Halobia sp., Monotis sp.); Medium grey, aphanitic to plagioclase-phyric rhyolite intrusion; JBif coeval with Bonanza Group volcanism 24 C limestone locally contains rare algal structures; may include coralline limestone re 24 LOWER CRETACEOUS ek Brownie (Sutton limestone equivalent in part; see below) near the top of the succession Nahshutti Ge Upper Valanginian to Barremian orgie Lake Lake Rannell LONGARM FORMATION EQUIVALENTS Sutton limestone equivalent: thin (<10m) unit of pale to medium grey, MAP SYMBOLS Lake Lake k massive reefoid limestone near the top of the Parson Bay Formation; 23 ee Greenish to brownish grey, thinly bedded to massive sandstone, siltstone, 22 Cr 23 contains silicified corals and other fossils; likely equivalent in part to 46 lKL mudstone, pebble conglomerate and minor coal; locally fossiliferous Geological contact, defined 21 Sutton limestone in the Cowichan Lake area, southern Vancouver Island Fi Lm i sh utt erm sh 40 Geological contact, approximate a Na Dark grey-green, basaltic tuff-breccia, crystal-lithic lapilli tuff and debris-flow n 56 30 UPPER TRIASSIC TO MIDDLE JURASSIC 45 uTrPvmc breccia; aphanitic to coarsely clinopyroxene-plagioclase±olivine-phyric Geological contact, inferred 22 67 57 22 BONANZA GROUP - NORTH OF HOLBERG FAULT 68 82 Creek Steeply dipping fault, defined h Lower (?Hettangian) to Middle (Bajocian) Jurassic 54 ug R P uTrPpmc Dark grey-green basaltic pillowed flows, pillow breccia and debris-flow breccia 63 iv 54 68 Isle HOLBERG VOLCANIC UNIT Steeply dipping fault, approximate er 28 40 45 45 71 28 35 72 30 Lake Undivided basaltic to rhyolitic flows, volcaniclastic and sedimentary rocks 21 21 Steeply dipping fault, inferred S 57 35 lmJH t 37 36 to the north of the map area Dark grey-green, andesitic tuff-breccia, lapilli tuff and debris-flow breccia; 39 24 30 uTrPvia plagioclase-hornblende-phyric Reverse fault, approximate (teeth on upper plate) 80 Tsulquate

River 5620000N 85 Mainly dark grey-green to medium grey, basaltic to andesitic flows and Reverse fault, inferred (teeth on upper plate) M mJHm volcaniclastic rocks including plagioclase-hornblende-phyric andesite, UPPER TRIASSIC a r 36 70 85 Unconformity, approximate y plagioclase-clinopyroxene-phyric basalt-andesite with sparse hornblende 24 5620000N megacrysts (~1cm), tuff-breccia, lapilli tuff and reworked equivalents; minor VANCOUVER GROUP 36 sedimentary rocks including volcanic breccia, wacke, siltstone, mudstone Unconformity, inferred 22 C 35 15 35 and shale; locally may include minor rhyolitic flows and tuffs Upper Triassic (Carnian to Lower Norian) re 75 Limit of mapping e 30 k QUATSINO FORMATION 19 35 80 19 80 85 Medium grey to grey-green, aphanitic to feldspar-phyric, rhyolitic to dacitic AC Medium to pale grey, thinly bedded to massive micritic limestone and locally bioclastic Line of vertical cross-section 22 28 50 mJHf flows, flow domes and/or pyroclastic rocks including flow and pyroclastic Brink 46 53 uTrQ limestone; minor silica replacement and chert nodules; rare laminated interbeds, oolitic k 42 22 breccia, welded to non-welded crystal-lithic lapilli tuff with carbonized wood Outcrop examined ee Lake Kains layers and algal structures; locally fossiliferous Cr 45 fragments; may locally include thin interbedded volcanic breccia and wacke, 47 74 38 58 Lake and minor basaltic to andesitic flows 18 90 18 Outcrop too small to show at map scale 36 60 20 43 20 k Upper Triassic (Carnian; possibly Middle Triassic (Ladinian) at the base) 57 24 Cree l 86 75 Brownish to greenish grey, laminated to medium-bedded, feldspathic Structure el 29 s 20 62 26 KARMUTSEN FORMATION s 25 46 mJHs volcanic wacke and pebbly sandstone locally cross-bedded with organic- 30 86 u 25 R ins rich horizons; and dark grey to black shale, mudstone and siltstone Bedding, inclined, vertical, overturned 15 32 Ka Undifferentiated, dark grey-green basalt flow/hyaloclastite/pillow lava 75 80 41 uTrK 14 17 55 17 (outside the map area) Eric Fisher 26 Volcanic flow lamination, inclined, vertical man 45 Dark grey-green volcaniclastic and sedimentary rocks including basaltic 30 Lake 14 45 lmJHvs ek R 20 37 55 to andesitic, plagioclase-clinopyroxene and plagioclase-hornblende-phyric re 34 62 i Upper Karmutsen Formation: Flow Member Eutaxitic foliation/welding, inclined C 42 25 21 ve 20 90 lapilli tuff and tuff breccia, volcanic breccia, wacke and minor siltstone 45 r 55 49 85 64 55 30 50 69 45 55 and mudstone; locally includes basaltic to andesitic flows Patrick 37 12 Dark grey-green, aphanitic to plagioclase-phyric basalt flows, commonly Dike, inclined, vertical 15 75 uTruKf 16 37 72 k 16 amygdaloidal and locally exhibiting laminar flow features (vesicle trains) 70 38 e St 19 85 e 40 Tertiary dike, inclined, vertical r 72 Upper Triassic (Norian) to Lower Jurassic (Sinemurian or younger) and pipe vesicles; may include minor pillow lava and hyaloclastite 10 42 25 G 15 45 25 70 21 10 C 32 30 o 27 37 k 62 o e d 30 RIVER SILTSTONE-WACKE Axis of minor fold, inclined 13 re s 57 Dark grey-green, plagioclase-megacrystic (1-2cm) basalt flows; commonly C 50 p 15 32 32 66 38 e 25 82 amygdaloidal and locally exhibiting trachytoid texture; intercalated with 17 er e Dark grey to grey-green, medium bedded to thinly laminated, siliceous siltstone, uTruKfx Riv d 10 80 aphanitic or plagioclase-phyric basalt near the top of the succession Axial plane of minor fold, inclined 15 63 30 40 54 15 TrJN mudstone and feldspathic lithic wacke; locally contains massive beds of basaltic 88 52 45 eed er to andesitic volcaniclastic breccia and thin rhyolitic tuff beds 20 oodsp p 42 65 Axis of primary flow fold, inclined G el Hushamu Small outcrop of plagioclase-megacrystic (1-2cm) basalt flow; commonly 16 H 35 26 65 82 37 arp amygdaloidal and locally exhibiting trachytoid texture; intercalated with Axial plane of primary flow fold, inclined 37 Sh 15 40 60 Upper Triassic (Carnian to Rhaetian) 44 18 44 aphanitic or plagioclase-phyric basalt near the top of the succession Soren 25 Lakes 62 70 17 14 33 29 60 14 PARSON BAY FORMATION Lineation, inclined (slickenfibres on steeply dipping fault) Lake 30 30 45 62 Ri 77 ve Similar lithologies to those found south of the Holberg-Stranby River fault system; Dark grey-green, massive to laminated, basalt pillow breccia and Ludvig r 60 75 uTruKh Lineation, vertical (slickenfibres on steeply dipping fault) 30 42 uTrP coarser sedimentary and volcaniclastic deposits appear to be less common hyaloclastite sandstone Lake 50 26 J and Sutton limestone equivalent has not been observed Lineation, horizontal (slickenfibres on steeply dipping fault) e 28 H 53 ns u 54 30 28 e s 13 n h 52 13 75 a 35 Plagioclase-megacrystic (<2cm) basalt pillow breccia and hyaloclastite Axial trace of anticline m 35 79 43 u 85 BONANZA GROUP - SOUTH OF HOLBERG FAULT uTruKhx sandstone 36 30 C 25 Lower Jurassic (Upper Pliensbachian) Fossils r e 38 32 e 17 k HATHAWAY CREEK VOLCANIC-SEDIMENTARY UNIT Dark grey-green, closely packed, pillowed basalt flows; aphanitic and TIN uTruKp Macrofossil locality (fossil age code below; identification by E. T. Tozer, 12 37 51 12 variably amygdaloidal Kelley 42 C Dark grey to greenish grey, massive to medium bedded, heterolithic volcanic H. W. Tipper and J. W. Haggart) r Island 40 22 50 e lJHCvs e breccia, feldspathic lithic wacke and siltstone 64 40 TlC(W) 30 70 k 28 33 GSC Macrofossil locality (fossil age code below) 70 50 23 28 56 Plagioclase-megacrystic (<2cm) pillowed basalt flows 33 uTruKpx TC 35 72 Dark grey to grey-green, pillowed to massive, plagioclase-megacrystic (<2cm) 27 30 Conodont locality (fossil age code below; identification by M. J. Orchard) 11 33 34 11 lJHCpx basaltic to andesitic flows; texturally similar to units lJLx/lJLpx 25 87 45 57 70 TeN 34 Thin (<8m) beds and lenses of pale to medium grey, micritic to rarely GSC Conodont locality (fossil age code below; identification by 12 44 33 38 47 45 5610000N uTruKls 45 30 Dark grey-green, massive to medium bedded and locally laminated, weakly calcareous, bioclastic or oolitic limestone intercalated with basalt near the top of M. J. Orchard) lJHCs feldspathic lithic wacke, siltstone, mudstone and minor shale, volcanic breccia and the flow succession 21 30 T 40 50 water-washed, basaltic lapilli tuff; carbonized wood fragments and locally fossiliferous Radiolarian locality (fossil age code below; identification by F. Cordey) 87 70 22 30 82 11 Cles k 54 76 5610000N 60 70 44 klagh e 16 J 25 20 re Thin (0.5-5m) beds and lenses of inter-volcanic limestone of unit uTruKls 36 50 C Lower Jurassic (Hettangian to Upper Sinemurian) GSC Radiolarian locality (fossil age code below; identification by 80 35 18 2 46 45 24 57 F. Cordey) 30 33 LE MARE LAKE VOLCANIC UNIT 54 28 88 46 40 36 34 68 P 44 G 28 Undifferentiated basaltic to rhyolitic flows and pyroclastic rocks (mainly subaerial); 09 48 l Y 35 09 Fossil age designation e e o 75 17 47 g r 90 32 47 u lJL includes ash-flow and rare airfall tuff and reworked equivalents, minor pillow lava, pillow 47 a u 15 g 30 10 16 tt 35 p h T Late Triassic; J Jurassic; K Cretaceous 35 e p breccia, hyaloclastite and rare pyroclastic surge deposits, locally intercalated with marine Selected References 48 17 m a 55 k 34 n e 29 to non-marine volcanic conglomerate, sandstone, siltstone, mudstone, impure limestone e early; m middle; l late 26 e 32 5 55 r C 70 Breitsprecher, K. and Mortensen, J. K. (2004): BCAge 2004A-1: a database of isotopic age determinations 43 r 70 and debris-flow deposits 31 C 37 e 14 ek 64 30 for rock units from British Columbia; Ministry of Energy and Mines, Open File 2004-3 (Release 3.0). C Carnian; N Norian; R Rhaetian S 74 C 28 Late Triassic: 08 a r 23 08 75 n e 24 48 C 58 Dark grey-green, basaltic to andesitic flows with minor intercalated volcaniclastic and 24 43 e 35 r Haggart, J. W. and Tipper, H. W. (1994): New results in Jura-Cretaceous stratigraphy, northern Vancouver Jurassic: H Hettangian; S Sinemurian; 34 k 28 ee 45 lJLm sedimentary lithotypes similar to unit lJLvs; locally includes minor pillow lava/breccia; 45 30 24 50 k Island, British Columbia; Geological Survey of Canada, Paper 1994-E, pages 59-66. 37 36 33 may include minor rhyolitic flows and pyroclastic rocks P Pliensbachian; T Toarcian 48 Janousek, V., Farrow, C. M. and Erban, V. (2006): Interpretation of whole-rock geochemical data in igneous 50 44 Medium grey, rhyolitic to dacitic flows, flow domes and/or pyroclastic rocks, including Cretaceous: B Berriasian; V Valanginian 38 petrology: introducing Geochemical Data Toolkit (GCDkit); Journal of Petrology, Volume 47, pages 1255-1259. 07 34 07 lJLf flow and pyroclastic breccias, welded to non-welded crystal-lithic lapilli tuff and rare 30 40 51 g 32 18 30 airfall tuff; aphanitic to feldspar-phyric; locally may include thin sedimentary deposits, H Hauterivian; B Barremian in 78 42 25 Jeletzky, J. A. (1976): Mesozoic and ?Tertiary rocks of , Vancouver Island, British Columbia; n 55 30 n Josef high-silica andesite and minor basaltic flows Geological Survey of Canada, Bulletin 242, 243 pages. Cape 50 o Henriksen Point Cn Cenomanian; C Coniacian R 32 86 35 Palmerston 32 34 24 37 Norton Point Dark grey-green, plagioclase-megacrystic (0.8-2cm), variably amygdaloidal basaltic Muller, J. E. and Roddick, J. A. (1983): Geology, Alert Bay - Cape Scott, British Columbia; Geological Survey 32 20 Ammonite Zone: (W) Welleri; (C) Cordilleranus; 06 43 55 06 lJLx to andesitic flows; locally intercalated with aphanitic and plagioclase-phyric flows; of Canada, Map 1552A, scale 1:250 000. M 58 (Ca) Canadensis; (O) Obtusum; 62 35 55 ac 37 texturally similar to plagioclase-megacrystic Karmutsen basalt in units uTruKf/ Muller, J. E., Northcote, K. E. and Carlisle, D. (1974): Geology and mineral deposits of Alert Bay - Cape Scott 35 ja 55 28 43 c 22 46 uTruKfx/uTruKhx/uTruKpx k 45 21 map area, Vancouver Island, British Columbia; Geological Survey of Canada, Paper 74-8, 77 pages. (R) Raricostatum 40 80 28 52 65 Dahlstrom 48 86 17 43 40 54 Point 5 Panteleyev, A., Reynolds, P. H. and Koyanagi, V. M. (1995): 40 Ar/ 39 Ar ages of hydrothermal minerals in acid Conodont Zone: (N) upper Nodosus 48 70 34 eek 33 R r 43 44 C 80 Small outcrop of plagioclase-megacrystic basaltic to andesitic flows of unit lJLx sulphate-altered Bonanza volcanics, northern Vancouver Island (92L/12); in Geological Fieldwork 1994, Grant, 05 k i 51 55 38 47 05 ac 33 v 46 37 47 Jules u upper cj 56 R 34 e 40 54 Michelsen B. and Newell, J. M., editors, Ministry of Energy, Mines and Petroleum Resources, Paper 1995-1, pages 61-65. a i r M 32 v 37 Point e 35 ay 45 k Bay (no label indicates age indeterminate; 30 r 36 w 49 80 ee 48 tha 32 36 25 r Steiger, R. H. and Jäger, E. (1977): Subcommission on geochronology: convention on the use of decay 38 Ha C Dark grey-green, plagioclase-megacrystic basaltic to andesitic pillowed flows; combined codes indicate age/zone range) R a f t 28 Hathaw lJLpx constants in geo- and cosmochronology; Earth and Planetary Science Letters, Volume 6, pages 359-362. R 80 ay 50 texturally equivalent to units lJLx/lJHCpx iv 25 27 e 24 26 04 r 48 28 04 Geochronology 32 45 38 Streckeisen, A. and LeMaitre, R. W. (1979): A chemical approximation to the modal QAPF classification of the C o v e 27 32 27 76 31 50 Grey-green sedimentary strata including impure limestone, calcareous to non- igneous rocks; Neues Jahrbuch für Mineralogie Abhandlungen, Volume 136, pages 169-206. 45 80 15 28 16 75 34 U-Pb zircon date (Ma, 2 sigma); Zrd, detrital zircon (determined by 46 27 50 lJLs calcareous mudstone, shale, siltstone, sandstone and tuffaceous equivalents; 50 44 40 R. M. Friedman) 62 16 44 may include minor intercalated tuff and volcaniclastic breccia 30 43 31 76 03 30 45 03 Interbedded volcaniclastic and sedimentary strata; includes lithic and crystal-lithic K/Ar date (Ma, 2 sigma error); Bi, biotite (Breitsprecher and 38 50 28 30 WHOLE-ROCK GEOCHEMISTRY LEGEND 75 lJLvs lapilli tuff and reworked equivalents, pyroclastic and epiclastic volcanic breccia, Mortensen, 2004) ek 38 Commerell re sandstone, siltstone, mudstone, impure limestone, and minor debris-flow and C 34 25 Point Moore 55 L (MgO>12 wt %) Basaltic Dacite- 40 39 ow phreatomagmatic deposits; may include minor lava flows Ar/ Ar date (Ma, 2 sigma error); Hb, hornblende (determined by er Classification Picrite Basalt Andesite Andesite Rhyolite Plutonic Rocks 27 27 D. A. Archibald) 35 Lake SiO wt % _ _ _ 02 36 A 02 2 < 53 < 53 >53 < 57 >57 < 63 > 63 50 Dark grey-green, basaltic to andesitic lapilli tuff, tuff-breccia and reworked h

Topkn d w 39 ot 46 a lJLvp equivalents locally interbedded with pillow lava, pillow breccia, fine-grained 40 39 h Ar/ Ar date (Ma, 2 sigma error); Hb, hornblende; Sc, sericite; 47 en 50 i D c hyaloclastite and minor lava flows Volcanic Rocks Major Intrusions Al, alunite (Breitsprecher and Mortensen, 2004; Panteleyev et al., 1995) k h Lake 43 r e 50 20 a e e 35 o 42 35 v r 82 i 24 l

t C Least altered o 35 R Metamorphism 01 20 67 48 40 01 44 15 40 43 Alkali metasomatized 51 28 55 45 Hornblende hornfels facies: hornblende+plagioclase±epidote±quartz C 46 54 re 37 21 5600000N Severely altered * e 28 G k 43 Upper greenschist facies: actinolite+chlorite+albite±epidote±quartz a l ±calcite 54 a yina * High proportions of veinlets and/or amygdule fillings, or pervasive fine-grained alteration, commonly involving chlorite, epidote, 36 to la 40 34 K albite, calcite, quartz, sericite, prehnite, zeolites and clay minerals, and less commonly actinolite, potassium feldspar and pumpellyite. 77 57 20 38 Holberg 5600000N 40 10 Prehnite-pumpellyite facies mainly: pumpellyite±prehnite+chlorite+albite 75 25 o 54 28 43 C 30 75 K n i Fault ±epidote±quartz±calcite r 50 36 e r e 30 m 16 p e 27 Early Jurassic Middle Jurassic k 65 37 p o IUGS Lm 40 25 s 50 K 35 o Zeolite facies and acid-sulphate alteration assemblages: Lm, laumontite; 99 n 99 Classification H Mt Brandes Nahwitti Lake Hushamu Wanokana Mesonorm Al, alunite; Zu, zunyite; Ml, melanterite; Rz, rozenite; Pp, pyrophyllite; 38 55 42 a 38 34 50 w St, stilbite (X-ray diffraction determinations by M. Chaudry); maximum 20 i Pluton Batholith Creek Pluton vs CIPW 26 s Creek Pluton Q Topknot 60 n regional zeolite-grade metamorphism developed in Middle Jurassic Wedel 75 a Point 10 k 60 w Holberg volcanic rocks north of the Holberg-Stranby fault system Island 38 15 i 35 98 k Cr 98 Lm e U re 65 eek C Retrograde zeolite mineral assemblages: Lm, laumontite (X-ray diffraction p r C 46 e p e ag g gd tn 50 e determination by M. Chaudry)

55 k k r B e e A e 34 20 ar 40 r h 50 B 44 w C C i 52 44 ree s Mineralization h 65 k h 90 i 97 o c 97 20 m e Leeson C h 12 l ree o 43 k a t 52 15 r MINFILE locality (092L 052/102I 014) 40 o t k qmd/ qdi/ a e 52/014 47 l s n re aqs qs qm 33 39 w t o o d e C qmg qgb r K Lake p o im 5 25 S Topography C N P A P 48 ek C 65 A e r r 55 k 65 r 28 ee 57 e e in k 52 e 74 e as sy mz md/mg di/gb 96 46 C sht k 24 r 96 CIPW (wt %) normative compositions projected in QAP: Q (qz), A (Or) and P (Ab+An) taking Fe2O3 as 0.15FeOt (total Fe as FeO). Grey diamonds fall in Lake 47 48 49550000E 51 52 53 54 55 56 57 60 Greenwood ua 53 C n Q 26 48 the extension of the Wanokana Creek Pluton in the Quatsino-Port McNeill area (Geoscience Map 2011-2). Nomenclature of plutonic rocks on the map is ag, alkali-feldspar granite; g, granite; gd, granodiorite; tn, tonalite; aqs, o 48 s Point 44 alkali-feldspar qz syenite; qs, qz syenite; qm, qz monzonite; qmd/qmg, e 20 based on the IUGS modal QAP mineralogical classification. Any discrepancy between modal and CIPW rock nomenclature is due in part to the projection Flooded land (swamp) e 65 56 C erg qz monzodiorite/qz monzo-gabbro; qdi/qgb, qz diorite/qz gabbro; as, 66 L reek 13 scheme. The CIPW projection of least altered plutonic rocks (n=96; grey/black dots) yields an overabundance of Or in the norm due to the presence of 35 alkali-feldspar syenite; sy, syenite; mz, monzonite; md/mg, monzodiorite/ 55 49 McNiffe umb K-bearing mafic hydrous minerals (biotite, hornblende) relative to the mesonorm (red crosses); the latter produces a bias towards tonalite in the granitoid Stream or river 41 44 34 68 Robson Bl 95 95 rocks (not a common rock type) whereas the CIPW projection shows bias towards quartz monzodiorite (much less common than quartz diorite). monzogabbro; di/gb, diorite/gabbro Hazard Cove East 25 40 Contour (100m) Point 14 e ak 36 Schloss Cove 30 L 37 Spencer 45 66 34 Island Holberg - Winter Harbour Area 56 Spot height (m) 59 tel Cove Shapland 75 Bo 38 36 (parts of 92L/05, 12, 13; 44 50 94 42 66 11 30 Cove 94 D E F 102I/08, 09 & 16) 58 46 Road (gravel) 52 70 24 metres 55 Brockton Holberg Fault Nahwitti 77 50 50 24 Prideaux 42 75 12 25 47 Island 33 1500 River Fault 70 k 29 38 Point e 63 Port McNeill 57 re 30 Notes Acknowledgments C 42 23 17 TrJBvs 26 45 1000 uTrQ 93 Matthews 75 70 93 50 Nordstrom All isotopic dates are calculated using We sincerely appreciate the warm hospitality shown 47 40 Island 44 uTrQ TrJN y 45 30 57 20 Monday uTrQ mJHf JIpo the decay constants recommended to us by the residents of northern Vancouver Island. er Cove Rocks British om 500 TrJN by Steiger and Jäger (1977); recent We thank Mike and Sophie Moore and Dave Ross 70 tg 42 32 26 Bedwell on estimates of K decay constants would for accommodations in Winter Harbour and Holberg, Campbell River M 45 52 Islands May lJLm lmJHvs 37 Point C increase the 40 Ar/ 39 Ar age by ca. 1%. respectively. Western Forest Products Inc., kindly l 0 92 26 e 92 52 a K uTrQ provided maps and digital files of logging roads in 31 90 Koskimo g Geology in remote areas and outside Vancouver 62 h e uTrP uTrQ w the area. Critical reviews by L. J. Diakow, N. W. D. Columbia 46 Hunt Islands lmJHvs uTruKf the limit of mapping was compiled 64 q -500 lJLm uTrP Islets u uTrP from BC Assessment Reports and Massey, J. L. Nelson and P. Schiarizza substantially Lippy 48 o mJHm mJHm JIqdi-gd Island 58 46 d improved the final cartographic product. Sadly, two of Point i Muller and Roddick (1983). Montgomery 55 Islands e uTrP uTrQ our co-authors, Drs. E. T. Tozer and H. W. Tipper of Point 62 -1000 uTrQ uTruKf 91 75 91 the Geological Survey of Canada, passed away Vancouver C uTruKf 25 McAllister uTrQ Cliffe r uTruKf uTruKf uTruKf uTrmKh? recently; their contributions to invertebrate 30 e C Point Chapman e C anada Islet Mabbott k r -1500 palaeontology will be sorely missed. 2011-1 2011-2 Islet ee Kains Island k (no vertical exaggeration) USA Point 72 73 74 75 76 77 78 79580000E 81 82 83 84 8586 87 88 89 590000E 91 92 A B C Victoria 5590000N Pinnacle metres Browning Spencer Goodspeed 2011-3 2011-4 2011-5 50 Island Digital Cartography Data Compilation 1500 Inlet Fault Cove Fault River Fault 89 89 uTrP Base Map Information G. T. Nixon G. T. Nixon, K. A. Johnston, 1000 uTruKf 35 JIqdi-gd Olympic Magnetic M. C. Kelman and R. D. M. Rayner Kains Base map produced from digital TRIM (Terrain TrJN uTrQ 0 100 200 35 North lJLm Island 0º 46' Resource Inventory Management) 1:20 000-scale 500 lJLf lKL uTrP Cape topographic database, British Columbia Ministry of uKBsn TrJBvs uTrQ uTruKp Peninsula Approximate mean magnetic lJLf 88 Parkins 30 88 Natural Resource Operations. Recommended Citation TrJN kilometres declination February 2011 for 0 uTrP lmJHvs

centre of map area: 18 degrees North Grid Magnetic North American Datum 1983 (NAD83). Universal Nixon, G. T., Hammack, J.L., Koyanagi, V.M., Snyder, L. D., Payie, G. J., Panteleyev, A., 33 minutes east, decreasing Declination uKBcg uTruKf Transverse Mercator Projection (Zone 9). Elevation in Massey, N.W.D., Hamilton, J.V., Orr, A. J., Friedman, R. M., Archibald, D.A., Haggart, J.W., uTrQ uTrQ mJHm uTrP annually 12.6 minutes per year Orchard, M.J., Tozer, E.T., Tipper, H.W., Poulton, T. P., Palfy, J. and Cordey, F. (2011): -500 metres above mean sea level. Contour interval 100m. lJLm lJLm lJLm uTrP uTruKf JIqdi-qpo uTruKf JIqdi-gd Geology, geochronology, lithogeochemistry and metamorphism of the Holberg-Winter lJLm Harbour area, northern Vancouver Island; BC Ministry of Energy and Mines, JIpo uTrQ -1000 uTruKf uTruKf TrJN 58 59 560000E 61 62 63 64 65 66 67 68 69 570000E 71 Geoscience Map 2011-1, 1:50 000 scale. lJLm uTrmKh? lmJHvs uTrmKh? uTruKf uTrQ uTrP uTruKf -1500 (no vertical exaggeration) uTrmKh, Hyaloclastite Member of the Middle Karmutsen Formation (not exposed in the Holberg-Winter Harbour map area)