CF Gower Memoir 4

REGIONAL GEOLOGY OF EASTERN LABRADOR (EASTERN MAKKOVIK AND GRENVILLE PROVINCES)

Michael gabbro 1426 ± 6 Ma

Pinwarian Pegmatite 1499 +8/-7 Ma

Labradorian & Grenvillian Granodiorite/tonalite gneiss 1658 ± 5 Ma (zircon) 978 ± 4 Ma (titanite)

Labradorian Quartz diorite 1654 ± 5 Ma

C.F. Gower Memoir 4

St. John’s Newfoundland and Labrador 2019

REGIONAL GEOLOGY OF EASTERN LABRADOR (EASTERN MAKKOVIK AND GRENVILLE PROVINCES)

C.F. Gower

Memoir 4

St. John’s, Newfoundland 2019 AVAILABILITY

Portions of this publication are available for free download through GEOFILES https://gis.geosurv.gov.nl.ca/minesen/geofiles/ or obtained from Geoscience Publications and Information, Geological Survey, Department of Natural Resources, Government of Newfoundland and Labrador, P.O. Box 8700, St. John’s, NL, Canada A1B 4J6 ([email protected]).

The purchaser or end user agrees not to provide a digital reproduction or copy of this product to a third party. Derivative products should acknowledge the source of the data.

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Recommended citation: Gower, C.F. 2019: Regional geology of eastern Labrador (eastern Makkovik and Grenville provinces). Government of Newfoundland and Labrador, Department of Natural Resources, Geological Survey, St. John’s, Memoir 4, 654 pages. [Geofile LAB/1752]

ISBN: 978-1-55146-697-2 Charles F. Gower, Emeritus Geoscientist Regional Geology Section, Department of Natural Resources Government of Newfoundland and Labrador P.O. Box 8700, St. John’s, NL, Canada A1B 4J6

FRONTISPIECE

Although not all encompassing, the image captures some of the key events (U–Pb zircon dates) in the geological history of the Grenville Province in eastern Labrador. Late Paleoproterozoic Labradorian granitoid rocks are intruded by Early Mesoproterozoic Pinwarian pegmatite and then mid-Mesoproterozoic Michael gabbro. Pre-Grenvillian history is well displayed because Grenvillian effects were modest at this outcrop. Grenvillian orogenesis is expressed by boudinage of the Michael gabbro (outside frame of image), accentuation of fabric in Labradorian granitoid rocks, and U–Pb titanite age. See Plate 10.2 for more detail. CONTENTS

Page ABSTRACT ...... xxx ACKNOWLEDGMENTS...... xxxii

CHAPTER 1 – INTRODUCTION

1.1 LOCATION ...... 1 1.2 PHYSIOGRAPHY ...... 1 1.3 INFRASTRUCTURE AND LAND USE...... 4 1.3.1 HIGHWAYS ...... 4 1.3.1.1 Trans-Labrador Highway ...... 4 1.3.1.2 Secondary Road Access ...... 5 1.3.1.3 Possible Highway from Northwest River to Postville ...... 5 1.3.2 PARKS ...... 5 1.3.2.1 Mealy Mountains National Park...... 5 1.3.2.2 Provincial Parks and Reserves ...... 5 1.3.3 HYDROELECTRICITY...... 5

CHAPTER 2 – PREVIOUS MAPPING

2.1 EXPLORER STAGE (1860–1890)...... 7 2.2 GOVERNMENT SURVEY COASTAL MAPPING STAGE (1895–1960) ...... 7 2.3 GEOLOGICAL SURVEY OF CANADA MAPPING STAGE (1960–1975) ...... 9 2.4 TARGETED GEOLOGICAL MAPPING STAGE (1975–1979) ...... 11

CHAPTER 3 – SYSTEMATIC 1:100 000-SCALE MAPPING OF EASTERN LABRADOR

3.1 MDA I (1979–1981) ...... 13 3.2 COOPERATIVE MINERALS PROGRAM (1982–1983)...... 13 3.3 MDA II (1984–1989) ...... 15 3.4 MDA III (1991–1995) ...... 15 3.5 PROVINCIAL FUNDING (1996–2000) ...... 15 3.6 PROVINCIAL FUNDING (POST 2000)...... 15 3.7 COMMENTS REGARDING MAPPING...... 15

CHAPTER 4 – PREVIOUS OTHER (NON-MAPPING) GEOLOGICAL STUDIES

4.1 REGIONAL REVIEWS AND ‘BEYOND EASTERN LABRADOR’ CORRELATIONS ...... 17 4.2. GEOCHRONOLOGY ...... 17 4.2.1 K–Ar AND Ar–Ar...... 17 4.2.1.1 K–Ar ...... 17 4.2.1.2 Ar–Ar ...... 18 4.2.2 Rb–Sr...... 18 4.2.3 Sm–Nd...... 19 4.2.4 U–Pb ...... 19 4.3 GEOPHYSICS...... 20 4.3.1 MAGNETIC ...... 20 4.3.2 GRAVITY ...... 20

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4.3.3 SEISMIC...... 20 4.3.4 PALEOMAGNETIC ...... 21 4.4 IGNEOUS PETROLOGY ...... 21 4.5 METAMORPHIC PETROLOGY...... 22 4.6 STRUCTURAL, TECTONIC AND GEODYNAMIC STUDIES...... 22 4.7 POST-GRENVILLIAN SUPRACRUSTAL ROCKS...... 22 4.8 SURFICIAL DEPOSITS ...... 23

CHAPTER 5 – INTRODUCTION TO REGIONAL GEOLOGY

5.1 MAKKOVIK PROVINCE...... 25 5.2 GRENVILLE PROVINCE...... 27 5.2.1 ‘EAGLE RIVER’ (LATE MAKKOVIKIAN) OROGENESIS (1810–1775 Ma) ...... 28 5.2.2 LABRADORIAN OROGENESIS (1710–1600 Ma) ...... 28 5.2.3 PINWARIAN OROGENESIS (1520–1460 Ma) ...... 35 5.2.4 POST-PINWARIAN–PRE-GRENVILLIAN EVENTS (1460–1090 Ma) ...... 35 5.2.5 GRENVILLIAN OROGENESIS (1090–985 Ma) AND LATE- TO POST-GRENVILLIAN EVENTS (985–920 Ma) ...... 35 5.2.6 NEOPROTEROZOIC AND PHANEROZOIC EVENTS ...... 36

CHAPTER 6 – PALEOPROTEROZOIC MAKKOVIK PROVINCE

(P2C, P3A 1900–1700 Ma)

6.1 SYN-MAKKOVIKIAN AILLIK GROUP (1885–1850 Ma) ...... 37

6.1.1 SOUTH OF BURNT ISLAND FELSIC VOLCANIC ROCKS (P2Cvf, P2Cvi) ...... 38 6.1.2 ‘LITTLE DOUBLE ISLAND’ FELSIC VOLCANIC ROCKS (P2Cvf/P2Cgd)...... 39 6.1.3 DOUBLE ISLAND FELSIC VOLCANIC ROCKS (P2Cvf, P2Css, P2Cvm) ...... 40 6.1.4 TUKIALIK BAY (EAST) FELSIC VOLCANIC ROCKS (P2Cvf) ...... 41 6.1.5 DEUS CAPE (WEST OF) FELSIC VOLCANIC ROCKS (P2Cvf/P2Csq) ...... 41 6.1.6 CAPE HARRISON METAMORPHIC SUITE FELSIC VOLCANIC ROCKS (P2Cvf/P2Cgd) ...... 42 6.1.7 TESSIALUK POND FELSIC VOLCANIC ROCKS (P2Cvf, P2Cvp) ...... 44 6.1.8 WEST OF BYRON BAY (P2Cvf) ...... 44 6.1.9 AILLIK GROUP MISCELLANEOUS...... 45 6.2. SYN- TO LATE-MAKKOVIKIAN GRANITOID ROCKS (1840–1820 Ma) ...... 45

6.2.1 DEUS CAPE GRANITOID ROCKS (P2Cgp)...... 45 6.3 LATE MAKKOVIKIAN (1820–1800 Ma) ...... 46

6.3.1 CAPE HARRISON METAMORPHIC SUITE (P2Cgd, P2Cgp, P2Cgr, P2Cmz) ...... 46 6.3.2 CAPE HARRISON METAMORPHIC SUITE CORRELATIVES? (P2Cgd, P2Cgr)...... 47 6.3.3 WHITE BEAR ISLANDS GRANULITE COMPLEX (P2Cgd, P2Cgp, P2Cgr, P2Cmz, P2Cdr) ...... 48 6.4 LATE- TO POST-MAKKOVIKIAN GRANITOID ROCKS (1800–1790 Ma) ...... 50 6.4.1 WESTERN CAPE HARRISON DOMAIN ...... 50

6.4.1.1 Big River Granitoid Rocks (P2Cgr, P2Cga) ...... 50 6.4.1.2 Stag Bay Granodiorite (P2Cgp) ...... 52 6.4.1.3 Numok Intrusive Suite (P2Cmz, P2Cmq, P2Cgr, P2Cyq)...... 54 6.4.1.4 ‘Little Double Island’ Granitoid Rocks (P2Cgd) ...... 55 6.4.1.5 Double Island Granitoid Rocks (P2Cgr, P2Cgp, P2Cgd) ...... 55 6.4.2 EASTERN CAPE HARRISON DOMAIN ...... 55

6.4.2.1 Byron Bay Granitoid Rocks (P2Cgp, P2Cgr, P2Cga) ...... 56 6.4.2.2 Cape Rouge Granitoid Rocks (P2Cgp, P2Cga) ...... 57 6.4.2.3 Alliuk Bight Granitoid Rocks (P2Cgp, P2Cgr, P2Cmz) ...... 58

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6.4.3 GRANITOID INTRUSIONS SOUTH OF THE CAPE HARRISON DOMAIN ...... 58

6.4.3.1 White Bear Lake Granitoid Rocks (P2Cgr) ...... 58 6.4.3.2 Lake Michael Megacrystic Granitoid Rocks (P2Cgp) ...... 59 6.4.3.3 South of Tessialuk Pond Granitoid Rocks (P2Cya) ...... 60 6.4.3.4 South of Byron Bay Granitoid Rocks (P2Cgr) ...... 60 6.4.3.5 Alliuk Bight (South) Megacrystic Granitoid Rocks (P2Cgp) ...... 60 6.4.3.6 Smokey Area Granitoid Rocks (P2Cgp, P2Cgd, P2Cgr, P2Cmz) ...... 61 6.5 POST-MAKKOVIKIAN GRANITOID ROCKS IN THE CAPE HARRISON DOMAIN (ca. 1720 Ma) ...... 62 6.5.1 ALKALI-FELDSPAR SYENITE ...... 62

6.5.1.1 Ragged Islands Alkali-feldspar Syenite (P2Cya) ...... 63 6.5.1.2 Tilt Cove Alkali-feldspar Syenite (P2Cya)...... 63 6.5.1.3 Holton Harbour Syenite to Alkali-feldspar Syenite (on map as P3Cyq) ...... 63 6.5.2 GRANITE AND ALKALI-FELDSPAR GRANITE ...... 64

6.5.2.1 Dog Islands Granite (P2Cga) ...... 64 6.5.2.2 Tukialik Granite (P2Cga) ...... 66

CHAPTER 7 – LATE PALEOPROTEROZOIC (PRE-LABRADORIAN)

SUPRACRUSTAL ROCKS (P3A 1810–1770 Ma)

7.1 INTRODUCTION...... 67 7.2 ISOTOPIC DATA ...... 67 7.2.1 U–Pb DATA ...... 67 7.2.1.1 Maximum Age of Deposition Based on Inherited Zircon ...... 67 7.2.1.2 Minimum Age of Deposition Based on Field Relationships ...... 69 7.2.1.3 Minimum Age of Deposition Based on Time of Metamorphism...... 69 7.2.1.4 Depositional Age Based on Interlayered Volcanic Rocks ...... 70 7.2.1.5 Conclusions Regarding Depositional Age of Supracrustal Gneiss ...... 70 7.2.2 OTHER ISOTOPIC DATA...... 70 7.2.2.1 Sm–Nd ...... 70 7.2.2.2 Rb–Sr ...... 70 7.2.2.3 K–Ar and Ar–Ar ...... 71 7.3 FIELD AND PETROGRAPHIC CHARACTERISTICS ...... 73 7.3.1 GROSWATER BAY TERRANE ...... 74

7.3.1.1 Mulligan Bay (P3Asp) ...... 74 7.3.1.2 Main River (P3Asp, P3Ass) ...... 74 7.3.1.3 East of Double Mer Barrens (P3Asp, P3Ass) ...... 76 7.3.1.4 Tom Luscombe Brook to Black Island (P3Asp, P3Ass, P3Asq) ...... 77 7.3.1.5 Nats Discovery Point (P3Ass?) ...... 79 7.3.1.6 Cuff Island (P3Avf/P3Ass)...... 80 7.3.1.7 George Island (P3Ass) ...... 80 7.3.1.8 Entry Island and Correlatives (on map as P2Csp) ...... 81 7.3.1.9 Cape Porcupine to Curlew Harbour (P3Asp) ...... 81 7.3.1.10 Sandy Bay (P3Asp)...... 82 7.3.2 HAWKE RIVER TERRANE; METASEDIMENTARY REMNANTS IN EARL ISLAND INTRUSIVE SUITE ...... 83

7.3.2.1 Southeast Sandwich Bay Assemblage (P3Asp, P3Ass, P3Asq, P3Asc, P3Avm) ...... 83 7.3.3 HAWKE RIVER TERRANE; PARADISE METASEDIMENTARY GNEISS BELT ...... 84

7.3.3.1 Mafic Extrusive Rocks (P3Avm, P3Aam) ...... 84 7.3.3.2 Calc-silicate Rocks (P3Asc) ...... 87 7.3.3.3 Quartzite/Metachert (P3Asq) ...... 87

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7.3.3.4 Psammitic Gneiss (P3Ass) ...... 88 7.3.3.5 Pelitic Gneiss (P3Asp) ...... 89 7.3.3.6 Diatexite (P3Asx) ...... 97 7.3.3.7 Ultramafic Rocks (on map as P3Cum)...... 97 7.3.3.8 Mafic Plutonic Rocks and Mafic Dykes (on map as P3Bam, P3Cam, P3Crg, P3Cd) ...... 98 7.3.3.9 Dioritic Rocks (on map as P3Bdr, P3Cdr) ...... 98 7.3.3.10 Granitoid Rocks (on map as Various P3B, P3C Units) ...... 99 7.3.4 HAWKE RIVER TERRANE; METASEDIMENTARY GNEISS IN WHITE BEAR ARM COMPLEX...... 99 7.3.5 LAKE MELVILLE TERRANE ...... 100 7.3.5.1 General Review...... 100

7.3.5.2 Double Mer White Hills Metasedimentary Gneiss (P3Asp, P3Asc, P3Ass) ...... 106 7.3.5.3 Jordans Point Metasedimentary Gneiss (P3Ass, P3Asc) ...... 106 7.3.5.4 English River Metasedimentary Belt (P3Asq, P3Ass, P3Asp) ...... 108 7.3.5.5 East Backway Metasedimentary Gneiss Sliver (P3Ass, P3Asp, P3Avm)...... 108 7.3.5.6 Barron Lake Metasedimentary Gneiss Package (P3Asx, P3Ass, P3Asp) ...... 108 7.3.5.7 Gilbert Bay Metasedimentary Gneiss (P3Asp, P3Ass, P3Asx) ...... 109 7.3.5.8 U-Bend Metasedimentary Gneiss (P3Ass, P3Asx, P3Asp) ...... 110 7.3.6 MEALY MOUNTAINS TERRANE...... 110

7.3.6.1 East Mealy Metasedimentary Gneiss (P3Asp, P3Ass, P3Asx) ...... 110 7.3.6.2 Muskrat Lake Metasedimentary Gneiss Slivers (P3Asp)...... 117 7.3.6.3 Southwest Pond Metasedimentary Gneiss (P3Asp, P3Ass)...... 117

CHAPTER 8 – PRE-LABRADORIAN GRANITOID ROCKS

IN GRENVILLE PROVINCE (P3A 1800–1710 Ma)

8.1 EAGLE RIVER COMPLEX (P3Agd, P3Adr, P3Agr, P3Aam) ...... 119 8.1.1 NORTHERN SEGMENT OF EAGLE RIVER COMPLEX ...... 119 8.1.2 SOUTHERN SEGMENT OF EAGLE RIVER COMPLEX ...... 122

CHAPTER 9 – EARLY LABRADORIAN ANORTHOSITIC, MAFIC

AND ULTRAMAFIC ROCKS (P3B 1710–1660 Ma)

9.1 ALEXIS RIVER ANORTHOSITIC INTRUSION ...... 123

9.1.1 ANORTHOSITE AND LEUCOGABBRONORITE (P3Ban, P3Bln) ...... 124 9.1.2 GABBRONORITE (P3Brg) ...... 127 9.1.3 ULTRAMAFIC ROCKS (P3Bum)...... 127 9.1.3.1 Olivine Dominant ...... 127 9.1.3.2 Hornblende Dominant...... 129 9.1.3.3 Oxide Dominant ...... 129

9.1.4 MAFIC GRANULITE (P3Bag) ...... 129 9.1.5 AMPHIBOLITIC GNEISS (P3Bam) ...... 129 9.1.6 DIORITIC/QUARTZ DIORITIC GNEISS (P3Bdr) ...... 129 9.1.7 GRANITOID GNEISSIC ROCKS (P3B MISCELLANEOUS) ...... 130 9.1.8 MAFIC DYKES (P3Bd)...... 130 9.1.9 OBSERVATIONS REGARDING METAMORPHISM BASED ON PETROGRAPHIC STUDIES ...... 130

9.2 UPPER EAGLE RIVER MAFIC INTRUSION (P3Brg, P3Bag, P3Bln) ...... 130 9.2.1 UPPER EAGLE RIVER MAFIC INTRUSION CORRELATIVE? (P3Brg, P3Bag) ...... 131

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9.3 UNASSIGNED ULTRAMAFIC ROCKS (P3Bum)...... 132 9.3.1 LAKE MELVILLE TERRANE ...... 132 9.3.2 MEALY MOUNTAINS TERRANE...... 132

9.4 UNASSIGNED MAFIC AND RELATED ROCKS (P3B VARIOUS) ...... 134 9.4.1 LAKE MELVILLE TERRANE ...... 134 9.4.2 MEALY MOUNTAINS TERRANE...... 135

CHAPTER 10 – EARLY LABRADORIAN GRANITOID AND

ASSOCIATED ROCKS (P3B 1710–1660 Ma)

10.1 GROSWATER BAY TERRANE GRANITOID GNEISS ...... 128 10.1.1 ISOTOPIC DATA ...... 128 10.1.1.1 U–Pb ...... 128 10.1.1.2 Sm–Nd ...... 140 10.1.1.3 Rb–Sr ...... 140 10.1.1.4 Ar–Ar and K–Ar ...... 141

10.1.2 FIELD AND PETROGRAPHIC CHARACTERISTICS (P3Bdr, P3Bgd, P3Bgp, P3Bgr, P3Bmq) ...... 141 10.2 HAWKE RIVER TERRANE GRANITOID GNEISS (EARL ISLAND INTRUSIVE SUITE) ...... 144 10.2.1 ISOTOPIC DATA ...... 144 10.2.2 FIELD CHARACTERISTICS ...... 148

10.2.2.1 Diorite and Quartz Diorite (P3Bdr) ...... 148 10.2.2.2 Tonalite and Granodiorite (P3Bgd, P3Bgp) ...... 150 10.2.2.3 Granite (P3Bgr) ...... 150 10.2.2.4 Monzodiorite and Monzonite (P3Bmq) ...... 150 10.2.2.5 Mafic Dykes (P3Bd)...... 150 10.2.3 PETROGRAPHY ...... 151 10.3 LAKE MELVILLE TERRANE GRANITOID GNEISS ...... 151 10.3.1 ISOTOPIC DATA ...... 152 10.3.1.1 U–Pb ...... 152 10.3.1.2 Sm–Nd ...... 152 10.3.1.3 Rb–Sr ...... 152 10.3.1.4 Ar–Ar and K–Ar ...... 153 10.3.2 FIELD AND PETROGRAPHIC CHARACTERISTICS...... 153

10.3.2.1 Granodiorite to Granite Gneiss (Non-megacrystic) (P3Bgd, P3Bgr) ...... 153 10.3.2.2 Megacrystic Gneissic Granitoid Rocks (P3Bgp) ...... 154 10.3.2.3 Dioritic Rocks (P3Bdr)...... 157 10.3.2.4 Alkali-feldspar Granitoid Rocks and Syenite (P3Bga, P3Bya) ...... 158 10.3.3 WESTERN LAKE MELVILLE TERRANE ...... 159

10.3.3.1. Megacrystic Granitoid Rocks (P3Bgp) ...... 159 10.3.3.2 Non-megacrystic Granitoid Rocks (P3Bgd, P3Bgr, P3Bya) ...... 159 10.3.4 LAKE MELVILLE TERRANE VS. GROSWATER BAY TERRANE GRANITOID GNEISS ...... 160 10.4 MEALY MOUNTAINS TERRANE GRANITOID GNEISS ...... 160 10.4.1 ISOTOPIC DATA ...... 160 10.4.1.1 U–Pb ...... 160 10.4.1.2 Sm–Nd ...... 161 10.4.2 FIELD AND PETROGRAPHIC CHARACTERISTICS...... 162

10.4.2.1 Granodiorite to Granite Gneiss (P3Bgd, P3Bgr) ...... 162 10.4.2.2 Megacrystic Granitoid Gneiss (P3Bgp) ...... 162 10.4.2.3 Dioritic Gneiss (P3Bdr) ...... 163 10.4.2.4 Monzonite Gneiss (P3Bmn, P3Bmq) ...... 163

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CHAPTER 11 – LATE LABRADORIAN MAFIC AND ANORTHOSITIC INTRUSIVE BODIES (AND CLOSELY ASSOCIATED

GRANITOID ROCKS) (P3C 1660–1600 Ma)

11.1 INTRODUCTION ...... 165 11.2 CAPE HARRISON DOMAIN, MAKKOVIK PROVINCE ...... 166 11.2.1 ADLAVIK INTRUSIVE SUITE...... 166

11.2.1.1 Gabbroic Rocks (P3Crg, P3Cln, P3Cmn) ...... 167 11.2.1.2 Dioritic Rocks (P3Cdr) ...... 168 11.2.2 KOKKORVIK DYKES CORRELATIVES (P3Cd) ...... 168 11.2.3 PAMIULIK POINT MAFIC INTRUSION (P3Crg, P3Cmn) ...... 170 11.2.4 FALSE CAPE MAFIC–MONZONITIC INTRUSION (P3Cmn, P3Cmq) ...... 170 11.2.5 WEST OF BRIG HARBOUR ISLAND MAFIC INTRUSION (P3Crg, P3Cln, P3Cmn, P3Cum) ...... 171 11.2.6 UNNAMED OTHER ADLAVIK INTRUSIVE SUITE POSSIBLE CORRELATIVES (P3Crg, P3Cln, P3Cam, P3Cmn, P3Cum) ...... 172 11.3 GROSWATER BAY TERRANE ...... 172

11.3.1 POTTLES BAY MAFIC INTRUSION (P3Crg) ...... 173 11.3.2 PORCUPINE STRAND (WEST) MAFIC INTRUSIONS (P3Crg, P3Cln, P3Cam) ...... 173 11.3.3 GRADY ISLAND MAFIC INTRUSION (P3Crg, P3Cmz)...... 175 11.3.4 SPOTTED ISLAND (AND SURROUNDINGS) MAFIC INTRUSION (P3Crg, P3Cmz) ...... 178 11.3.5 UNNAMED OTHER ADLAVIK INTRUSIVE SUITE POSSIBLE CORRELATIVES (P3Crg, P3Cln, P3Cam, P3Cmn, P3Cum) ...... 179 11.3.5.1 General ...... 179 11.3.5.2 Petrography ...... 179

11.3.5.3 Mafic Dykes (P3Cd) ...... 180 11.4 HAWKE RIVER TERRANE ...... 181

11.4.1 DYKES RIVER MAFIC INTRUSIONS (P3Cum, P3Crg, P3Cln, P3Cln) ...... 181 11.4.2 DYKES RIVER MAFIC INTRUSIONS POSSIBLE CORRELATIVES (P3Cum, P3Crg) ...... 183 11.4.3 METAMORPHOSED MAFIC DYKES IN THE EARL ISLAND INTRUSIVE SUITE (P3Cd) ...... 184 11.4.3.1 Field Description...... 184 11.4.3.2 Age ...... 184 11.4.3.3 Petrography ...... 185 11.4.4 WHITE BEAR ARM COMPLEX AND SAND HILL BIG POND INTRUSION ...... 185 11.4.4.1 General Description ...... 185 11.4.4.2 Structure ...... 186 11.4.4.3 Age of WBAC and SHBP...... 189

11.4.4.4 Ultramafic Rocks (P3Cum) ...... 190 11.4.4.5 Anorthosite (P3Can) ...... 190 11.4.4.6 Leucogabbronorite and Leucotroctolite (P3Cln, P3Clt)...... 191 11.4.4.7 Gabbronorite, Troctolite (P3Crg) ...... 192 11.4.4.8 Monzogabbronorite (P3Cmn) ...... 192 11.4.4.9 Mafic Granulite (P3Cag) ...... 193 11.4.4.10 Amphibolite, Diorite and Gneissic Equivalents (P3Cam, P3Cdr) ...... 193 11.4.4.11 Metamorphic Zonation in Gabbronorite, Troctolite and their Leucocratic and/or Metamorphic Equivalents ...... 194

11.4.4.12 Mafic Dykes Within White Bear Arm Complex (P3Cd) ...... 197

11.4.4.13 Monzonite and Quartz Monzonite (P3Cmz, P3Cmq, P3Cgp) ...... 199 11.4.4.14 Granodiorite, Granite, Alkali-feldspar Granite and Quartz Syenite (P3Cgd, P3Cgr, P3Cga, P3Cyq) ...... 200

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11.4.5 WHITE BEAR ARM COMPLEX CORRELATIVE(?) AND BARRON LAKE GRANITOID ROCKS ...... 201

11.4.5.1 White Bear Arm Complex Correlative? (P3Cln, P33Can)...... 201 11.4.5.2 Barron Lake Granitoid Rocks (on map as P3Bgr or P3Cgr) ...... 201 11.4.6 SANDWICH BAY (NORTHWEST) MAFIC INTRUSION (P3Cam, P3Cln) ...... 203 11.5 LAKE MELVILLE TERRANE...... 203

11.5.1 MOUNT GNAT MAFIC GRANULITE BELT (P3Cag, P3Cam, P3Crg, P3Cln) ...... 203 11.5.2 SPILLOVER MAFIC–INTERMEDIATE ROCKS (P3Cam/P3Crg)...... 204 11.6 MEALY MOUNTAINS TERRANE...... 205 11.6.1 MEALY MOUNTAINS INTRUSIVE SUITE ...... 205

11.6.1.1 Anorthosite, Leucotroctolite, Leuconorite (P3Can, P3Clt, P3Cln) ...... 206 11.6.1.2 Monzonorite (P3Cmn) ...... 217 11.6.1.3 Dioritic Rocks (P3Cdr) ...... 219 11.6.1.4 Monzonite (P3Cmz) ...... 219 11.6.1.5 Quartz Monzonite (P3Cmq) ...... 222 11.6.1.6 K-feldspar Megacrystic Monzonite, Syenite and Granite (P3Cgp) ...... 222 11.6.1.7 Alkali-feldspar Granite, Granite and Quartz Syenite (P3Cga)...... 224 11.6.1.8 Granite (P3Cgr)...... 225 11.6.1.9 Isolated Intrusions East of MMIS...... 225 11.6.2 DOUBLE MER WHITE HILLS (MMIS CORRELATIVE?) ...... 227

11.6.2.1 Leucogabbronoritic and Dioritic Granulite (P3Cag, P3Cam, P3Cdr, P3Cln) ...... 227 11.6.2.2 Monzonitic Granulite (P3Cmz) ...... 227 11.6.2.3 Granitic Granulite (P3Cgr, P3Cgp, P3Cga, P3Cgd, P3Cmq) ...... 228 11.6.2.4 Mafic Dykes (P3Cd) ...... 228

CHAPTER 12 – LATE LABRADORIAN GRANITOID

INTRUSIONS (P3C 1660–1600 Ma)

12.1 CAPE HARRISON DOMAIN, MAKKOVIK PROVINCE ...... 229 12.1.1 MOUNT BENEDICT INTRUSIVE SUITE...... 229

12.1.1.1 Gabbro and Diorite (P3Crg, P3Cdr)...... 229 12.1.1.2 Monzonite, Syenomonzonite and Syenite (P3Cmz, P3Cyq) ...... 230 12.1.1.3 Syenite, Quartz Syenite and Granite (P3Cga) ...... 231 12.1.1.4 Other Rock Types ...... 232

12.1.2 JEANETTE BAY QUARTZ SYENITE (P3Cyq)...... 234 12.1.3 WALKER LAKE QUARTZ MONZONITE (P3Cmq)...... 234 12.1.4 CROOKED RIVER GRANITE (P3Cgr) ...... 235 12.2 GROSWATER BAY TERRANE ...... 235

12.2.1 DOUBLE MER PLUTON (P3Cyq, P3Cga, P3Cmq) ...... 235 12.2.2 TOM LUSCOMBE BROOK GRANITOID INTRUSION (P3Cyq/P3Cgr) ...... 236 12.2.3 SNOOKS COVE GRANITOID INTRUSION (P3Cgr/P3Cyq)...... 237 12.2.4 POTTLES COVE HEAD SUITE (P3Cmz, P3Cgr)...... 238 12.3 HAWKE RIVER TERRANE ...... 239

12.3.1 CARTWRIGHT INTRUSIVE SUITE (P3Cgp, P3Cmq)...... 239 12.3.1.1 Description and Age ...... 239 12.3.1.2 Petrography...... 240

12.3.2 HAWKE BAY COMPLEX (P3Cdr, P3Cgd, P3Cgp, P3Cam)...... 241 12.3.2.1 Description ...... 241 12.3.2.2 Age and Origin ...... 243

12.3.3 CAPE BLUFF POND GRANITOID INTRUSIONS (P3Cgp, P3Cgd, P3Cga) ...... 243

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12.3.4 PARADISE ARM PLUTON (P3Cgp) ...... 244 12.3.4.1 Description and Age ...... 244 12.3.4.2 Petrography...... 246 12.3.4.3 Origin ...... 247

12.3.5 PARADISE ARM PLUTON SATELLITE (P3Cgp) ...... 247 12.4 LAKE MELVILLE TERRANE...... 248

12.4.1 THE BACKWAY MEGACRYSTIC GRANITOID BELT (P3Cgp) ...... 248 12.4.1.1 Paradise Arm – The Backway Granitoid Unit Correlation...... 248 12.5 MEALY MOUNTAINS TERRANE ...... 249

12.5.1 MIDDLE EAGLE RIVER PLUTON (P3Cmq, P3Cga) ...... 249 12.5.1.1 Isotopic Data ...... 249 12.5.1.2 Field Description...... 249

CHAPTER 13 – LATE PALEOPROTEROZOIC AND EARLY MESOPROTEROZOIC (PM 1810–1350 Ma)

13.1 PINWARE TERRANE SUPRACRUSTAL ROCKS ...... 251 13.1.1 CRITERIA FOR IDENTIFYING PROTOLITH OF MEDIUM- TO HIGH-GRADE SUPRACRUSTAL QUARTZOFELDSPATHIC GNEISSES ...... 251 13.1.2 UPPER ST. AUGUSTIN RIVER DISTRICT ...... 254 13.1.2.1 Quartzite and Psammitic Gneiss (PMsq, PMss)...... 255 13.1.2.2 Anomalous ‘Tonalitic’ Gneiss (PMtn) ...... 257 13.1.2.3 Pelitic Gneiss and Metasedimentary Diatexite (PMsp, PMsx) ...... 257 13.1.3 HENLEY HARBOUR DISTRICT ...... 258 13.1.3.1 Banded Amphibolite (PMvm)...... 259 13.1.3.2 Felsic Volcanic/Volcanoclastic Protolith (PMvf) ...... 261 13.1.3.3 Quartzofeldspathic Rocks Derived from Clastic Metasediments (PMss) ...... 263 13.1.3.4 Quartzite and Quartz-rich Meta-arkose (PMsq) ...... 265 13.1.3.5 ‘Tonalitic’ Gneiss (PMtn) ...... 266 13.1.3.6 Pelitic Rocks (Muscovite-bearing) (PMsp) ...... 266 13.1.3.7 Pelitic Rocks (Sillimanite ± Cordierite-bearing) (PMsp)...... 268 13.1.3.8 Calc-silicate Rocks (PMsc)...... 271 13.2 PINWARE TERRANE FOLIATED AND GNEISSIC GRANITOID ROCKS ...... 272 13.2.1 OVERVIEW OF ROCK TYPES PRESENT ...... 272 13.2.2 AGE OF PINWARE TERRANE GRANITOID ROCKS...... 274 13.2.3 SYENITIC, QUARTZ SYENITE AND ALKALI-FELDSPAR GRANITE (PMyq) ...... 276 13.2.3.1 Specific Details of Unit PMyq Granitoid Rocks ...... 277 13.2.4 GRANITE (PMgr) ...... 277 13.2.4.1 Specific Details of Unit PMgr Granitoid Rocks...... 279 13.2.5 QUARTZ MONZONITE AND MONZONITE (PMmq) ...... 281 13.2.5.1 Specific Details of Unit PMmq Granitoid Rocks...... 282 13.2.6 GRANODIORITE AND MINOR TONALITE (PMgd, PMtn) ...... 284 13.2.6.1 Specific Details of Units PMgd and PMtn Granitoid Rocks ...... 285 13.2.6.2 Comment on Protolith of Granodioritic and Tonalitic Gneiss ...... 286 13.2.7 QUARTZ MONZODIORITE AND DIORITE (PMmd, PMdr)...... 286 13.2.7.1 Specific Details of Units PMmd and PMdr Granitoid Rocks ...... 287 13.2.8 K-FELDSPAR MEGACRYSTIC GRANITOID ROCKS (PMgp) ...... 288 13.2.8.1 Specific Details of Unit PMgp Granitoid Rocks ...... 288 13.2.9 COMMENTS ON WHOLE-ROCK GEOCHEMISTRY OF UNIT PM GRANITOID ROCKS ...... 290 13.3 PINWARE TERRANE FOLIATED AND GNEISSIC MAFIC ROCKS ...... 291 13.3.1 AMPHIBOLITE (PMam) ...... 291 13.3.1.1 Specific Details of Unit PMam Amphibolite ...... 293

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13.3.2 LEUCO-AMPHIBOLITE AND LEUCOGABBRONORITE (PMln)...... 296 13.3.3 GABBRO, NORITE, TROCTOLITE (PMrg) ...... 297 13.3.4 LARGER REMNANT ULTRAMAFIC TO MONZONORITIC BODIES IN THE PINWARE TERRANE ...... 297 13.3.4.1 Specific Details of Larger Remnant Mafic Bodies...... 297

CHAPTER 14 – EARLY MESOPROTEROZOIC (M1 1600–1350 Ma)

14.1 PINWARE–MEALY MOUNTAINS TERRANE BOUNDARY MAFIC ROCKS ...... 301 14.1.1 NO-NAME LAKE MAFIC INTRUSION ...... 302

14.1.1.1 Olivine Gabbro/Melagabbro, Grading into Ultramafic Rocks (M1um) ...... 302 14.1.1.2 Gabbro and Leucogabbro (M1rg, M1ln) ...... 302 14.1.1.3 Amphibolite (M1am) ...... 303 14.1.1.4 Monzogabbro to Leucomonzogabbro (M1mn) ...... 305 14.1.1.5 Diorite to Monzodiorite (M1ln/M1mz) ...... 305 14.1.2 FOLD CLOSURE INTRUSIONS (M1rg) ...... 305 14.1.3 UPPER PARADISE RIVER INTRUSIVE SUITE (MAFIC–ANORTHOSITIC)...... 305

14.1.3.1 Gabbronorite to Ultramafic Rocks (M1um) ...... 306 14.1.3.2 Leucogabbronorite (M1ln) ...... 307 14.1.3.3 Anorthosite (M1an) ...... 308 14.1.3.4 Monzogabbronorite (M1mn) ...... 308 14.1.4 Kyfanan Lake Layered Mafic–Anorthositic Intrusion ...... 308

14.1.4.1 Ultramafic Rocks (M1um) ...... 309 14.1.4.2 Troctolite, Norite and Gabbro (M1rg)...... 310 14.1.4.3 Leucocratic Equivalents of Troctolite, Norite and Gabbro (M1ln)...... 310 14.1.4.4 Anorthosite and Anorthositic Gabbro (M1an)...... 310 14.1.4.5 Metamorphic Derivatives of the Previous Four Units ...... 311 14.1.4.6 Regional Variation in Mineral Assemblages ...... 311 14.1.5 SCATTERED OUTCROPS NORTH OF THE KYFANAN LAKE LAYERED INTRUSION

(M1dr, M1am, M1rg) ...... 311 14.1.6 TRIANGLE INTRUSION (M1an) ...... 311 14.1.7 ST. LEWIS RIVER GORGE REMNANT INTRUSIONS (M1um, M1rg/M1am) ...... 312 14.1.8 LONG HARBOUR MAFIC ROCKS (on map as PMrg, PMln, PMam)...... 312 14.2 PINWARE–MEALY MOUNTAINS TERRANE BOUNDARY FELSIC ROCKS...... 312 14.2.1 UPPER PARADISE RIVER INTRUSIVE SUITE (MONZONITE–GRANITE) ...... 312

14.2.1.1 Monzonite to Monzodiorite (M1mz)...... 313 14.2.1.2 Quartz Monzonite to Monzonite (M1mq)...... 315 14.2.1.3 Quartz Syenite, Syenite, Minor Alkali-feldspar Granite (M1yq) ...... 315 14.2.1.4 Granite, Alkali-feldspar Granite, Minor Quartz Monzonite (M1gr)...... 316 14.2.2 PINWARE–MEALY MOUNTAINS TERRANE BORDER MAFIC–FELSIC WHOLE-ROCK CHEMISTRY...... 316 14.3 PINWARIAN ACTIVITY ELSEWHERE IN EASTERN LABRADOR ...... 317 14.3.1 MINOR GRANITOID INTRUSIONS ...... 317 14.3.2 METAMORPHIC OVERPRINTING...... 317 14.3.3 RESULTS CHALLENGED ...... 317

CHAPTER 15 – EARLY TO MIDDLE MESOPROTEROZIC (M1 1460–1350 Ma)

15.1 MICHAEL GABBRO (M1d) ...... 321 15.1.1 SUMMARY OF INVESTIGATIONS ...... 321 15.1.2 RECOGNITION OF MICHAEL GABBRO ...... 321

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15.1.3 GEOCHRONOLOGY...... 323 15.1.4 MINERAL ASSEMBLAGES...... 325 15.1.5 MINERAL CHEMISTRY...... 326 15.1.6 WHOLE-ROCK CHEMISTRY ...... 327

15.2 LINEAR MAFIC BODY IN CARTWRIGHT INTRUSIVE SUITE (on map as P3Crg) ...... 328 15.3 UPPER PARADISE RIVER MAFIC DYKES (M1d/M2d) ...... 330 15.4 MOKAMI HILL GRANITOID INTRUSION (M1gr/M1yq)...... 332

CHAPTER 16 – MIDDLE MESOPROTEROZOIC (M2 1350–1200 Ma)

16.1 FOX HARBOUR BIMODAL VOLCANIC BELTS ...... 335 16.1.1 DISCOVERY ...... 335 16.1.2 DESCRIPTION...... 336 16.1.3 GEOCHRONOLOGY...... 336

16.2 UPPER NORTH RIVER GRANITOID INTRUSION (M2gr, M2yq) ...... 337 16.3 MEALY DYKES (M2d)...... 339 16.3.1 MEALY DYKES IN MEALY MOUNTAINS REGION ...... 339 16.3.1.1 Introduction...... 339 16.3.1.2 Geochronology ...... 340 16.3.1.3 Description ...... 340 16.3.1.4 Petrography and Mineral Chemistry...... 342 16.3.1.5 Whole-rock Chemistry ...... 342 16.3.2 PERIPHERAL MEALY DYKES ...... 344 16.4 OTHER MAFIC INTRUSIVE ROCKS ...... 345

16.4.1 ISOLATED MAFIC ROCK OCCURRENCE AT CG00-205 (on map as M1d) ...... 345 16.4.2 LOURDES-DU-BLANC-SABLON GABBRONORITE (M2rg)...... 346 16.5 BATTLE ISLAND SUPRACRUSTAL ROCKS ...... 346 16.5.1 CROSSBEDDED PSAMMITE (on map as PMss) ...... 348 16.5.1.1 Geochronological Study of Crossbedded Psammite ...... 348 16.5.2 MIXED PSAMMITE, CALC-SILICATE SCHIST AND PELITIC SCHIST (on map as PMss) ...... 348 16.5.3 CALC-SILICATE ROCKS AND SEMI-PELITE (on map as PMsc) ...... 349 16.5.4 PSAMMITE (on map as PMss) ...... 349 16.5.5 CALC-SILICATE ROCKS (on map as PMsc)...... 349 16.5.6 CALCAREOUS PSAMMITE (on map as PMss/PMsc) ...... 350 16.5.7 BATTLE ISLAND SUPRACRUSTAL ROCKS CORRELATIVES? (on map as PMsp)...... 350

CHAPTER 17 – LATE MESOPROTEROZOIC (M3 1200–900 Ma)

17.1 PRE-GRENVILLIAN INTRUSIONS (M3A 1200–1090 Ma)...... 351 17.1.1 GILBERT BAY GRANITE (M3Agr)...... 351 17.1.1.1 Gilbert Bay Granite Peripheral Minor Granitic Intrusions (M3Agr) ...... 353 17.1.2 GILBERT BAY? MONZOGABBRONORITE (M3Amn)...... 353 17.1.3 AILLIK MAFIC DYKE CORRELATIVE? (on map as M3Bd) ...... 354 ca. 17.2 EARLY SYN-GRENVILLIAN INTRUSIONS (M3B 1090–1045 Ma) (p, f)...... 354 17.2.1 HENRIETTA ISLAND PEGMATITE ...... 356 17.2.2 SOUTHWEST BROOK GRANITE...... 356 17.2.3 BIOTITE GRANODIORITE DYKE ON PARADISE RIVER ...... 356 17.2.4 MECKLENBURG HARBOUR APLITIC VEIN...... 356 17.2.5 BEAVER BROOK MICROGRANITE DYKE ...... 357 ca. 17.3 LATE SYN-GRENVILLIAN INTRUSIONS (M3B 1045–985 Ma) ...... 357 17.3.1 FOLD-TEST INTRUSIONS (M3Bgp) ...... 357 17.3.2 TROUT RIVER HEADWATERS PLUTON? (M3Bgr/PMgr) ...... 359

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17.3.3 OUTSIDE BIG POND GRANITOID ROCKS (M3Bgr/PMgr) ...... 360 17.3.4 LATE SYN-GRENVILLIAN MINOR GRANITIC INTRUSIONS (p, f)...... 361 17.3.4.1 Battle Island Pegmatite ...... 361 17.3.4.2 L’Anse-au-Diable Pegmatite...... 361 17.3.4.3 Porphyroclastic Pegmatite ...... 362 17.3.4.4 Microgranite on St. Augustin River ...... 362 17.3.4.5 Second Choice Lake Pegmatite ...... 362 17.3.4.6 Pegmatite, Mealy Mountains Terrane...... 362 17.3.5 NEPHELINE-BEARING SYENITIC ROCKS ...... 362

17.3.5.1 Northwest of Black Bay Nepheline Syenite (M3Byn)...... 362 17.3.5.2 South of Kyfanan Lake Aegerine-/Nepheline-bearing Syenite (M3Byn) ...... 363 ca. 17.4 EARLY POST-GRENVILLIAN INTRUSIONS (M3C 985–975 Ma) ...... 365 17.4.1 RED BAY GABBRONORITE (M3Crg) ...... 365 17.4.2 NORTHWEST OF PINWARE GABBRONORITE (M3Crg) ...... 366 17.4.3 UPPER BEAVER BROOK INTRUSION ...... 366

17.4.3.1 Gabbronorite (M3Crg) ...... 366 17.4.3.2 Monzonorite (M3Cmn)...... 368 17.4.3.3 Quartz Monzonite and Granite (M3Cmq, M3Cgr) ...... 368 17.4.4 PICTON POND INTRUSION ...... 370

17.4.4.1 Monzonorite (M3Cmn)...... 370 17.4.4.2 Quartz Monzonite and Granite (M3Cmq, M3Cgr) ...... 370 17.4.5 LOWER PINWARE RIVER INTRUSION ...... 371

17.4.5.1 Leucogabbronorite (M3Cln)...... 371 17.4.5.2 Alkali-feldspar Syenite (M3Cyq) ...... 372 17.4.6 FOX POND PLUTON (M3Cyq) ...... 373 17.4.7 OTHER ALKALI-FELDSPAR SYENITE BODIES (M3Cyq) ...... 373 17.4.8 MAFIC DYKES (M3Cd) ...... 374 17.4.8.1 L’Anse-au-Diable Dykes...... 374 17.4.8.2 York Point Dykes ...... 379 17.4.8.3 Gilbert Bay Dykes ...... 379 17.4.8.4 Other Potentially Correlative Dykes...... 380 17.4.8.5 Lithogeochemistry of Late-Grenvillian Mafic Dykes ...... 381 ca. 17.5 LATE POST-GRENVILLIAN INTRUSIONS (M3D 975–955 Ma)...... 382 17.5.1 HISTORICAL BACKGROUND ...... 382 17.5.2 CHARACTERISTICS ...... 383 17.5.3 CROOKS LAKE MAP REGION...... 383

17.5.3.1 Lynx Lake Granite (M3Dgr)...... 383 17.5.3.2 North of Lynx Lake Granite (M3Dgp/M3Dgr) ...... 385 17.5.4 EAGLE RIVER MAP REGION...... 386

17.5.4.1 Eagle River Headwaters Granite (M3Dgr)...... 386 17.5.4.2 One-Legged Lake Monzonite (M3Dmq) ...... 386 17.5.4.3 13B10 West Monzonite to Quartz Monzonite (M3Dmz, M3Dmq) ...... 387 17.5.4.4 13B10 Southwest Granite to Alkali-feldspar Granite (Megacrystic in Part) (M3Dgp/M3Dgr) ...... 387 17.5.4.5 13B10 Southeast Seriate to Megacrystic Granite (M3Dgp/M3Dgr) ...... 388 17.5.4.6 13B09 Southeast Granite (M3Dgp/M3Dgr)...... 388 17.5.5 UPPER ST. AUGUSTIN RIVER MAP REGION ...... 388

17.5.5.1 13B05 North-central Syenite to Monzonite (M3Dyq/M3Dmq)...... 388 17.5.5.2 Joir River Granite (M3Dgr) ...... 389 17.5.5.3 Michaels River Monzonite to Alkali-feldspar Granite (M3Dmq, M3Dyq, M3Dgr) ...... 390 17.5.5.4 Halfway Pond Granite (M3Dgr)...... 391 17.5.5.5 Upper St. Augustin River Monzonite to Granite (M3Dmz, M3Dmq, M3Dyq, M3Dgr)...... 391 17.5.5.6 13B04 Southwest Monzonite to Syenite (M3Dmq/M3Dyq) ...... 391

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17.5.5.7 Matse River Quartz Monzonite to Quartz Syenite (M3Dmq) ...... 391 17.5.5.8 13B03 Central Quartz Monzonite (M3Dmq) ...... 393 17.5.5.9 13B03 Southeast Monzonite to Granite (M3Dmz, M3Dmq, M3Dgr)...... 393 17.5.6 UPPER ST. PAUL RIVER MAP REGION ...... 394

17.5.6.1 13B07 Central Granite (M3Dgr) ...... 394 17.5.6.2 13B02 Southwest Monzonite (M3Dmz)...... 394 17.5.6.3 13B02 South-central Monzonite (M3Dmq/M3Dmz)...... 394 17.5.6.4 Four Corners Lake Granite (M3Dgr) ...... 395 17.5.7 KYFANAN LAKE MAP REGION ...... 395

17.5.7.1 St. Lewis River Headwaters Granite (M3Dgr)...... 395 17.5.7.2 Upper St. Lewis River West Granite and Alkali-feldspar Granite (M3Dgr) ...... 395 17.5.7.3 Upper St. Lewis River North Granite (M3Dgr) ...... 396 17.5.7.4 Upper St. Lewis River East Monzonite (M3Dmq)...... 396 17.5.7.5 Upper St. Paul River North Granite (M3Dgr) ...... 396 17.5.7.6 Upper St. Paul River Northwest Monzonite to Syenite (M3Dmq, M3Dyq) ...... 396 17.5.7.7 Upper St. Paul River Northeast Granite (M3Dgr) ...... 398 17.5.7.8 Upper St. Paul River West Granite (M3Dgr) ...... 398 17.5.7.9 Upper St. Paul River East Monzonite to Alkali-feldspar Granite (M3Dmq, M3Dgr)...... 399 17.5.7.10 Rivière Bujeault West Quartz Monzonite to Granite (M3Dmq, M3Dgr) ...... 399 17.5.7.11 Rivière Bujeault Headwaters Alkali-feldspar Quartz Syenite to Granite (M3Dyq, Locally M3Dgr) ...... 399 17.5.8 PORT HOPE SIMPSON MAP REGION ...... 401

17.5.8.1 Southwest Pond Granite (M3Dgr) ...... 401 17.5.9 ST. LEWIS RIVER MAP REGION ...... 401

17.5.9.1 Upper Pinware River Granite (M3Dgr, Locally M3Dgp) ...... 401 17.5.9.2 Chateau Pond Granite (M3Dgr, Locally M3Dmq)...... 402 17.5.10 PINWARE MAP REGION ...... 403

17.5.10.1 Lac Senac Granite (M3Dgr, Locally M3Dmq) ...... 403 17.5.10.2 Stokers Hill Granite (M3Dgr)...... 403 17.5.11 UNEXPOSED PLUTONS (M3D?) ...... 403 17.5.12 LATE- TO POST-GRENVILLIAN MINOR INTRUSIONS (M3Dgr, f, p) ...... 404 17.5.13 UPPER ST LEWIS RIVER (EAST) MAFIC DYKES (M3Dd) ...... 406 17.5.14 GENERAL OBSERVATIONS ON POST-GRENVILLIAN PLUTONS ...... 406 17.5.15 SOME LITHOGEOCHEMICAL FEATURES OF LATE MESOPROTEROZOIC GRANITOID PLUTONS...... 407

CHAPTER 18 – NEOPROTEROZOIC

18.1 SUPRACRUSTAL ROCKS ...... 409 18.1.1 DOUBLE MER FORMATION (NDm) ...... 409 18.1.1.1 Historical Background ...... 409 18.1.1.2 Double Mer Half-graben...... 409 18.1.1.3 Lake Melville Graben ...... 411 18.1.1.4 The Lake Melville Rift System ...... 411 18.1.1.5 Depositional Environment ...... 412 18.1.1.6 Age of the Double Mer Formation ...... 412 18.1.2 DOUBLE MER FORMATION CORRELATIVES ...... 413 18.1.2.1 Churchill River ...... 413 18.1.2.2 Kenamu River ...... 413 18.1.2.3 The Backway (NDm) ...... 413 18.1.2.4 Sandwich Bay Conglomerate (NSb)...... 414 18.1.2.5 Gilbert River Arkose (NGi) ...... 414

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18.1.2.6 Clastic Dykes on the Shore of Lake Melville (Nc) ...... 415 18.1.2.7 Clastic Dykes on Great Caribou Island (Nc) ...... 416 18.1.2.8 Clastic Dykes at St. Augustin ...... 416 18.1.3 LOWER LABRADOR GROUP...... 416 18.1.3.1 Bateau Formation (NCBa) ...... 418 18.1.3.2 Regolith on Southernmost St. Peter Islands (Included with NCLc) ...... 418 18.1.3.3 Lighthouse Cove Formation (NCLc) ...... 418 18.2 LONG RANGE DYKES, QUARTZ VEINS AND CARBONATE VEINS ...... 420 18.2.1 LONG RANGE DYKES (Nd) ...... 420 18.2.1.1 White Bear River Estuary Dyke Corridor ...... 420 18.2.1.2 Earl Island Dyke Corridor ...... 423 18.2.1.3 Cartwright Island Dyke Corridor ...... 425 18.2.1.4 Curlew Harbour Dyke Corridor ...... 427 18.2.1.5 Table Bay Dyke Corridor ...... 428 18.2.1.6 Open Bay Dykes ...... 428 18.2.1.7 Cooper Island Dyke Corridor ...... 428 18.2.1.8 Double Island (Southeast of Battle Island) and Truck Island ...... 430 18.2.1.9 Distribution of K-feldspar in Long Range Dykes ...... 430 18.2.1.10 Lithogeochemistry of Long Range Dykes ...... 432 18.2.2 QUARTZ VEINS (Nq) ...... 432 18.2.2.1 St. Lewis River Area...... 432 18.2.2.2 Upper Alexis River ...... 433 18.2.2.3 Upper Paradise River Area ...... 434 18.2.2.4 No-Name Lake Area ...... 435 18.2.2.5 Island of Ponds ...... 435 18.2.3 CARBONATE VEINS (Nc) ...... 435 18.2.3.1 Lake Melville Rift System ...... 435 18.2.3.2 Sandwich Bay Graben ...... 435

CHAPTER 19 – PHANEROZOIC

19.1 EARLY CAMBRIAN ...... 437 19.1.1 UPPER LABRADOR GROUP...... 437 19.1.1.1 Bradore Formation (CBr) ...... 437 19.1.1.2 Forteau Formation (CFo) ...... 437 19.2 DEVONO–CARBONIFEROUS AND/OR LATER (Dd) ...... 438 19.2.1 SANDWICH BAY DYKES ...... 438 19.2.2 NORMAN BAY DYKES ...... 438 19.2.3 BATTLE HARBOUR DYKE...... 439 19.2.4 CHARLOTTETOWN ROAD DYKES ...... 441 19.2.5 LITHOGEOCHEMISTRY OF PHANEROZOIC MAFIC DYKES ...... 441 19.3 SURFICIAL DEPOSITS ...... 442

CHAPTER 20 – STRUCTURE

20.1 MAKKOVIK PROVINCE (CAPE HARRISON DOMAIN) ...... 443 20.2 GRENVILLE PROVINCE...... 444 20.2.1 GROSWATER BAY TERRANE ...... 445 20.2.2 HAWKE RIVER TERRANE ...... 448 20.2.3 LAKE MELVILLE TERRANE ...... 449 20.2.4 MEALY MOUNTAINS TERRANE...... 455 20.2.5 PINWARE TERRANE ...... 458

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20.3 NEOPROTEROZOIC ...... 462 20.3.1 RIFT BASINS AND RELATED FAULTS...... 462 20.3.2 FAULT-RELATED MAFIC DYKES, QUARTZ VEINS AND CARBONATE VEINS ...... 463 20.4 CAMBRIAN...... 464 20.5 DEVONO–CARBONIFEROUS AND/OR LATER ...... 464 20.6 RECENT EARTHQUAKES ...... 465

CHAPTER 21 – REGIONAL METAMORPHISM

21.1 DISTRIBUTION OF METAMORPHIC MINERALS BY ROCK TYPE ...... 467 21.1.1 PELITIC GNEISS...... 467 21.1.2 OTHER SUPRACRUSTAL ROCK TYPES ...... 471 21.1.3 GRANITOID GNEISS ...... 471 21.1.4 MAFIC ROCKS ...... 475 21.2 PRESSURE–TEMPERATURE ESTIMATES ...... 475 21.2.1 SMOKEY ...... 475 21.2.2 DOUBLE MER ...... 481 21.2.3 RIGOLET ...... 481 21.2.4 SANDWICH BAY ...... 481 21.2.5 SAND HILL BIG POND ...... 481 21.2.6 PORT HOPE SIMPSON...... 482 21.2.7 PINWARE...... 482 21.2.8 GEOTHERMOBAROMETRIC SUMMARY ...... 482 21.3 INTERPRETATION OF METAMORPHISM BY PROVINCE/TERRANE ...... 483 21.3.1 MAKKOVIK PROVINCE (CAPE HARRISON DOMAIN) ...... 483 21.3.2 GROSWATER BAY TERRANE ...... 484 21.3.3 HAWKE RIVER TERRANE ...... 484 21.3.4 LAKE MELVILLE TERRANE ...... 486 21.3.5 MEALY MOUNTAINS TERRANE...... 486 21.3.6 PINWARE TERRANE ...... 486 21.4 POST-GRENVILLIAN METAMORPHISM ...... 487 21.4.1 LATE- TO POST-GRENVILLIAN PLUTONS ...... 487 21.4.2 LATE NEOPROTEROZOIC ...... 487

CHAPTER 22 – ISOTOPIC DATA SYNTHESIS

22.1 U–Pb ...... 489 22.1.1 1900–1700 Ma ...... 489 22.1.2 1700–1500 Ma ...... 491 22.1.3 1500–1100 Ma ...... 491 22.1.4 1100–900 Ma ...... 494 22.2 Rb–Sr ...... 496 22.2.1 SUITES TO WHICH REGRESSION ANALYSIS HAS BEEN APPLIED ...... 496 22.2.2 INITIAL Sr RATIOS FOR SINGLE SAMPLES DATED BY U–Pb METHODS ...... 497 22.3 Sm–Nd ...... 497 22.3.1 PALEOPROTEROZOIC AND EARLY MESOPROTEROZOIC FELSIC PLUTONIC AND VOLCANIC ROCKS...... 501 22.3.2 PALEOPROTEROZOIC METASEDIMENTARY AND MAFIC VOLCANIC ROCKS ...... 501 22.3.3 LATE PALEOPROTEROZOIC MAFIC PLUTONIC AND ANORTHOSITIC ROCKS ...... 504 22.3.4 MESOPROTEROZOIC MAFIC INTRUSIONS ...... 504 22.3.4.1 Michael Gabbro ...... 504

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22.3.4.2 Mealy Dykes ...... 504 22.3.4.3 Blanc-Sablon Gabbro ...... 505 22.3.5 MESOPROTEROZOIC FELSIC PLUTONIC ROCKS AND MINOR INTRUSIONS ...... 505 22.4 Ar–Ar AND K–Ar ...... 508

CHAPTER 23 – TECTONIC HISTORY

23.1 PRE-MAKKOVIKIAN AND MAKKOVIKIAN ...... 511 23.1.1 RIFTING STAGE (2250–2100 Ma) ...... 511 23.1.2 ACCRETIONARY PHASE (2100–1800 Ma) ...... 511 23.1.2.1 Approach and Accretion of an Outboard Arc (2100–1900 Ma)...... 511 23.1.2.2 Development of a Continental-margin Arc, Closely Followed by Back-arc Rifting (1900– 1850 Ma)...... 513 23.1.2.3 Formation/Accretion of a Second (Outboard?) Arc (1850–1800 Ma) ...... 513 23.1.2.4 Post-collisional Events (1800–1700 Ma) ...... 513 23.1.3 GRENVILLE PROVINCE CHRONOLOGICAL CORRELATIVES...... 513 23.2 PRE-LABRADORIAN AND LABRADORIAN (1800–1600 Ma) ...... 514 23.2.1 APPROACH OF OUTBOARD ARC, OR CONTINENTAL-MARGIN ARC (1800–1680 Ma) ...... 514 23.2.2 LABRADORIAN ARC MAGMATISM AND COLLISION(?) OF OUTBOARD ARC (1680–1645 Ma)...... 514 23.2.3 POST-COLLISIONAL LABRADORIAN EVENTS (1645–1600 Ma)...... 516 23.3 PRE-PINWARIAN AND PINWARIAN (1600–1460 Ma) ...... 516 23.3.1 POST-LABRADORIAN–PRE-PINWARIAN EVENTS (1600–1520 Ma) ...... 516 23.3.2 PINWARIAN OROGENESIS (1520–1460 Ma) ...... 516 23.4 POST-PINWARIAN–PRE-GRENVILLIAN (1460–1090 Ma) ...... 518 23.4.1 EARLY AND MIDDLE ELSONIAN (1460–1290 Ma) ...... 518 23.4.2 LATE ELSONIAN (1290–1230 Ma) ...... 518 23.4.3 POST ELSONIAN–PRE-GRENVILLIAN (1230–1090 Ma) ...... 518 23.5 GRENVILLIAN (1090–985 Ma) ...... 519 23.5.1 EVIDENCE FOR INDENTOR CONFIGURATION...... 519 23.5.1.1 Geochronological Data ...... 519 23.5.1.2 Structural Criteria ...... 519 23.5.1.3 Geophysical Criteria ...... 520 23.5.1.4 Indentor Model ...... 520 23.5.2 ROLE OF INDIVIDUAL TERRANES IN GRENVILLIAN INDENTOR MODEL ...... 522 23.5.2.1 Groswater Bay and Hawke River Terranes ...... 522 23.5.2.2 Lake Melville Terrane...... 523 23.5.2.3 Mealy Mountains and Pinware Terranes ...... 523 23.5.3 LATE GRENVILLIAN MAGMATIC EVENTS ...... 524 23.5.3.1 Early Posttectonic Magmatism (985–975 Ma)...... 524 23.5.3.2 Late Posttectonic Magmatism (975–955 Ma) ...... 524 23.5.3.3 Post-Grenvillian Waning (955–920 Ma)...... 524 23.6 POST-GRENVILLIAN...... 524

REFERENCES ...... 525

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APPENDIX 1 – MAPS AND DATABASE A1.1 MAPPING STYLE...... 547 A1.2 FEATURES OF THE 1:100 000-SCALE MAPS ...... 548 A1.2.1 MARGINAL NOTES ...... 548 A1.2.2 LEGEND ...... 548 A1.2.3 LITHOLOGICAL BOUNDARIES ...... 548 A1.2.4 MARGINAL MAPS ...... 548 A1.2.5 OTHER FEATURES ...... 549 A1.3 DATABASE...... 549 A1.3.1 DATA STATION TABLES ...... 549 A1.3.1.1 Data Station Location ...... 551 A1.3.1.2 Areas Mapped ...... 552 A1.3.1.3 Aerial Photographs...... 552 A1.3.1.4 Traverse Mode ...... 553 A1.3.1.5 Date of Field Observation ...... 554 A1.4 ROCK NAMES, UNIT NAMES AND UNIT DESIGNATORS ...... 554 A1.4.1 ROCK NAME ...... 554 A1.4.2 UNIT NAME ...... 555 A1.4.3 UNIT DESIGNATORS ...... 555 A1.5 FIELD PHOTOGRAPHS ...... 556 A1.6 STRUCTURAL DATA...... 556 A1.6.1 STRUCTURAL DATA ENTRY AND EDITING ...... 556 A1.7 SAMPLING...... 557 A1.7.1 FIELD PRACTICES ...... 557 A1.7.2 SAMPLES TABLE ...... 557 A1.7.2.1 Samples Collected During 1:100 000-scale Mapping ...... 557 A1.7.2.2 Samples Collected During other Mapping Projects in the Region ...... 558 A1.7.3 EARLY-PROJECT GEOCHRONOLOGY SAMPLE CONFUSION ...... 559 A1.8 PETROGRAPHIC DATA ...... 560 A1.9 MINERAL OCCURRENCES ...... 560 A1.10 MINERAL IDENTIFICATIONS ...... 561 A1.11 PALEOMAGNETIC DATA...... 561 A1.11.1 PUBLISHED STUDIES ...... 561 A1.11.1.1 Author Not Involved ...... 561 A1.11.1.2 Author Involved ...... 562 A1.11.2 UNPUBLISHED STUDIES...... 562 A1.12 GEOCHEMICAL DATA ...... 562 A1.12.1 SAMPLE COLLECTION ...... 562 A1.12.2 COMPILATION OF DATA ...... 562 A1.12.3 VALIDATION OF ANALYTICAL DATA ...... 563 A1.12.3.1 Comparisons Between Analytical Methods...... 563 A1.12.3.2 Comparisons Between Duplicate Samples ...... 563 A1.12.3.2 Comparisons with Controls (Standards) ...... 563 A1.13 GEOCHRONOLOGICAL DATA...... 564 A1.13.1 U–Pb GEOCHRONOLOGICAL DATA ...... 565 A1.13.2 Sm–Nd GEOCHRONOLOGICAL DATA...... 565 A1.13.3 Rb–Sr GEOCHRONOLOGICAL DATA...... 565 A1.13.4 K–Ar AND Ar–Ar GEOCHRONOLOGICAL DATA...... 565 A1.14 MISCELLANEOUS DATA TABLES...... 565 A1.14.1 GEOTHERMOBAROMETRIC DATA ...... 565 A1.14.2 OXYGEN ISOTOPIC DATA...... 565 A1.14.3 DYKES...... 565

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APPENDIX 2 – SELECTED STAINED SLABS Slab Image 6.1. Examples of Aillik Group potential correlatives (some mylonitic or migmatized) in the Cape Harrison domain ...... 568 Slab Image 6.2. Syn- to late-Makkovikian granitoid rocks (Deus Cape granitoid rocks, Cape Harrison Metamorphic Suite and possible correlatives, and White Bear Islands granulite complex (WBIGC); Cape Harrison domain and adjacent Grenville Province ...... 569 Slab Image 6.3. Late- to post-Makkovikian granitoid rocks in the Cape Harrison domain ...... 570 Slab Image 6.4. Post-Makkovikian granitoid rocks in the Cape Harrison domain ...... 571

Slab Image 7.1. Late Paleoproterozoic pelitic to psammitic supracrustal rocks (Groswater Bay and northwestern Lake Melville terranes) ...... 572 Slab Image 7.2. Late Paleoproterozoic supracrustal rocks of the Paradise metasedimentary gneiss belt ...... 573 Slab Image 7.3. Late Paleoproterozoic pelitic gneiss, calc-silicate rock, quartzite and diatexite in the Lake Melville terrane ...... 574 Slab Image 7.4. Late Paleoproterozoic pelitic gneiss in the East Mealy metasedimentary gneiss ...... 575

Slab Image 8.1. Pre-Labradorian granitoid rocks in the Grenville Province assigned to the Eagle River complex ...... 576

Slab Image 9.1 Early Labradorian Alexis River anorthositic intrusion and Upper Eagle River mafic intrusion ...... 577 Slab Image 10.1. Early Labradorian dioritic to granitic rocks in the Groswater Bay terrane...... 578 Slab Image 10.2. Early Labradorian dioritic to granitic rocks in the Hawke River terrane ...... 579 Slab Image 10.3. Early Labradorian granodioritic to granitic rocks in the Lake Melville terrane ...... 580 Slab Image 10.4. Early Labradorian granodioritic to granitic rocks in the Mealy Mountains terrane ...... 581

Slab Image 11.1. Late Labradorian mafic rocks in the Cape Harrison domain, Makkovik Province...... 582 Slab Image 11.2. Late Labradorian mafic rocks in the Groswater Bay terrane...... 583 Slab Image 11.3. Late Labradorian mafic rocks in the Hawke River terrane ...... 584 Slab Image 11.4. Late Labradorian mafic rocks in the Lake Melville terrane ...... 585 Slab Image 11.5. Late Labradorian anorthositic rocks in the Mealy Mountains intrusive suite, Mealy Mountains terrane...... 586 Slab Image 11.6. Late Labradorian monzogranitic rocks in the Mealy Mountains intrusive suite, Mealy Mountains terrane...... 587

Slab Image 12.1. Late Labradorian granitoid rocks, Makkovik Province ...... 588 Slab Image 12.2. Late Labradorian granitoid rocks, Groswater Bay terrane ...... 589 Slab Image 12.3. Late Labradorian granitoid rocks, Hawke River, Lake Melville, and Mealy Mountains terranes ...... 590

Slab Image 13.1. Pinware terrane supracrustal rocks; St. Augustin district ...... 591 Slab Image 13.2. Pinware terrane supracrustal rocks; Henley Harbour district (Pitts Harbour Group) ...... 592 Slab Image 13.3. Pinware terrane granitoid rocks (all having known Pinwarian U–Pb ages) ...... 593 Slab Image 13.4. Pinware terrane mafic rocks...... 594

Slab Image 14.1. Pinware–Mealy Mountains terrane boundary ultramafic to anorthositic rocks ...... 595 Slab Image 14.2. Pinware–Mealy Mountains terrane boundary felsic rocks ...... 596

Slab Image 15.1. Michael gabbro...... 597 Slab Image 15.2. Linear mafic body in Cartwright intrusive suite ...... 598 Slab Image 15.3. Upper Paradise River mafic dykes...... 598

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Slab Image 16.1. Upper North River granitoid intrusion and Fox Harbour volcanic belt ...... 599 Slab Image 16.2. Mealy dykes and other, possibly coeval, mafic rocks ...... 600 Slab Image 16.3. Battle Island supracrustal rocks ...... 601

Slab Image 17.1. Gilbert Bay granite and related? rocks ...... 602 Slab Image 17.2. Fold-Test intrusions ...... 603 Slab Image 17.3. Late syn-Grenvillian granitic, syenitic and nepheline-bearing syenitic intrusions ...... 604 Slab Image 17.4. Early post-Grenvillian mafic rocks ...... 605 Slab Image 17.5. Early post-Grenvillian felsic intrusions ...... 606 Slab Image 17.6. Early post-Grenvillian felsic (syenitic) intrusions (Lower Pinware River and Fox Pond bodies) ...... 607 Slab Image 17.7. Early post-Grenvillian mafic dykes (L’Anse-au-Diable, York Point, Gilbert Bay)...... 608 Slab Image 17.8. Late post-Grenvillian intrusions – west area ...... 609 Slab Image 17.9. Late post-Grenvillian intrusions – central-west area ...... 610 Slab Image 17.10. Late post-Grenvillian intrusions – central-east area ...... 611 Slab Image 17.11. Late post-Grenvillian intrusions – east area ...... 612

Slab Image 18.1. Double Mer Formation and clastic dykes ...... 613 Slab Image 18.2. Lower Labrador Group ...... 614 Slab Image 18.3. Long Range dyke – White Bear River estuary dyke corridor ...... 615 Slab Image 18.4. Quartz veins and fault breccia (despite labels, most are both) ...... 616

Slab Image 19.1. Phanerozoic mafic dykes ...... 617

xviii FIGURES Page Figure 1.1. Eastern Labrador showing area addressed in this report. A. Names and locations of 1:100 000-scale geological maps for eastern Labrador, B. Major communities and cultural features (present and proposed roads, parks and power transmission line) ...... 2 Figure 1.2. Physiographic features of eastern Labrador showing area addressed in this report. A. Digital elevation model, B. Hypsometrically tinted version of same data (pale-green – low elevations; brown – high elevations). Highest point is in Mealy Mountains at 1097 m...... 3 Figure 2.1. Early geological mapping in eastern Labrador. A. Lieber’s (1860) map showing eastern Labrador as underlain by ‘Domino’ gneiss (blue), B. Government survey coastal mapping 1890–1960 ...... 8 Figure 2.2. Geological mapping in eastern Labrador between 1960 and 1979. A. Geological Survey of Canada mapping (1960–1975), B. ‘Targeted’ geological mapping of specific areas (1975–1979). Note that year of mapping indicated, rather than year of publication ...... 10 Figure 3.1. Systematic 1:100 000-scale mapping of eastern Labrador. A. Data stations and areas colour coded according to six time-related stages of mapping. Non-matching dots indicate data collected outside the defined time period, B. Data stations and areas colour coded according to project year from 1979 onward. Data captured from Geological Survey of Canada projects carried out by Emslie (1976) and Hanmer and Scott (1990) are also shown ...... 14 Figure 5.1. Structural provinces in eastern Laurentia, also showing area addressed in this report...... 25 Figure 5.2. Pre-Labrador Sea reconstruction of relationship between Makkovik Province and Ketilidian Mobile Belt ...... 26 Figure 5.3. Simplified geological map of the Makkovik Province, showing domain classification, major structures and U–Pb emplacement ages ...... 27 Figure 5.4. Compilation geological map of the eastern Grenville Province ...... 28 Figure 5.5. Simplified geological map of eastern Labrador...... 30 Figure 5.6. Geological time and eastern Labrador. Right-hand column modified from Gower and Krogh (2002) ...... 32 Figure 5.7. Terranes and major geological structures in eastern Labrador (Gower et al., 2008a) ...... 33 Figure 5.8. Regional aeromagnetic map for eastern Labrador...... 34 Figure 6.1. Age of Aillik Group felsic volcanic rocks vs. Easting (suggesting eastward younging?) ...... 38 Figure 6.2. Distribution of Aillik Group correlative rocks in the Cape Harrison domain...... 38 Figure 6.3. Distribution of Cape Harrison Metamorphic Suite and potentially correlative rocks...... 45 Figure 6.4. Subdivision of late- to post-Makkovikian granitoid rocks in the Cape Harrison domain, and potentially correlative rocks to the south...... 52 Figure 6.5. Post-Makkovikian granitoid rocks in the Cape Harrison domain ...... 62 Figure 7.1. Distribution of late Paleoproterozoic (pre-Labradorian) supracrustal rocks in eastern Labrador, also locating sites offering depositional age constraints from geochronological data. Subareas addressed in text are indicated in boxed text...... 68 Figure 7.2. Distribution of selected metamorphic minerals in late Paleoproterozoic pelitic gneiss. A. Sillimanite, B. Kyanite, C. Garnet, D. Cordierite ...... 73 Figure 7.3. Distribution of selected metamorphic minerals in late Paleoproterozoic pelitic gneiss. A. Orthopyroxene, B. Osumilite, C. Sapphirine, D. Muscovite...... 74 Figure 7.4. Distribution of late Paleoproterozoic supracrustal rocks north of Lake Melville, also depicting metamorphic domain classification and locating geothermobarometric sites and results obtained from them (cf. Gower and Erdmer, 1988). 3a, 3b, and 3c are subdivisions of metamorphic domain 3. Apart from pelitic gneiss results, those four monzonitic granulites are also included...... 75 Figure 7.5. Distribution of late Paleoproterozoic supracrustal rocks flanking Groswater Bay. Some localities too small to be shown. See text for discussion regarding possible younger age for supracrustal rocks on Black Island ...... 77 Figure 7.6. Distribution of supracrustal rock types in Paradise metasedimentary gneiss belt, and associated meta-igneous rocks ...... 85

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Figure 7.7. Distribution of thin section locations and metamorphic minerals in Paradise metasedimentary gneiss belt pelitic gneiss. A. Thin section locations, B. Muscovite and staurolite, C. Sillimanite, D. Kyanite...... 89 Figure 7.8. Distribution of metamorphic minerals in Paradise metasedimentary gneiss belt pelitic gneiss and simplified metamorphic domain interpretation. A. Cordierite, B. Garnet, C. Orthopyroxene, osumilite and sapphirine, D. Metamorphic domain interpretation ...... 93 Figure 7.9. Distribution of selected metamorphic minerals in late Paleoproterozoic pelitic gneiss in the Lake Melville terrane. A. Sillimanite, B. Garnet, C. Cordierite, orthopyroxene and kyanite ...... 100 Figure 7.10. Progressive metamorphism in pelitic East Mealy metasedimentary gneiss ...... 111 Figure 8.1. Pre-Labradorian granitoid rocks in the Grenville Province assigned to the Eagle River complex ...... 119 Figure 9.1. Early Labradorian anorthositic, mafic and ultramafic intrusions (including Alexis River anorthositic intrusion and Upper Eagle River mafic intrusion)...... 124 Figure 10.1. Early Labradorian granitoid and associated rocks...... 137 Figure 11.1. Late Labradorian intrusive rocks focusing on mafic and anorthositic rocks and closely associated granitoid rocks. See next chapter for other late Labradorian granitoid rocks (left unla- belled in this figure)...... 166 Figure 11.2. Coastal cross-sectional exposure of the Pottles Bay mafic intrusion from field sketch and notes (CG82-027). Notes have been edited for readability. Total width of intrusion uncertain, but guestimated to be about 400 m. The intrusion was originally described from south to north and interpreted to be top-to-the-south. A key point of the figure is the interplay between igneous, metamorphic and deformational processes...... 174 Figure 11.3. Little Grady Island layered mafic–monzonitic intrusion, illustrating emplacement and deformational history (cf. O’Flaherty, 1986). If the plagioclase phenocrysts floated, then, of course, the sense of rotation would be reversed ...... 176 Figure 11.4. Rock type distribution in the White Bear Arm complex and Sand Hill Big Pond intrusion ...... 186 Figure 11.5. Structural framework for the White Bear Arm complex and Sand Hill Big Pond intrusion ...... 187 Figure 11.6. Interpreted mode of emplacement and subsequent deformation of the White Bear Arm complex ...... 188 Figure 11.7. Distribution of ultramafic rocks in White Bear Arm complex ...... 190 Figure 11.8. Metamorphic zonation in gabbronorite, troctolite, and their leucocratic and/or metamorphic equivalents. A. Field distribution of coronites and garnet, B. Metamorphic zonation based on petrographic observations (see text) ...... 195 Figure 11.9. Regional map of Mealy Mountains intrusive suite. Note that the eastern and western parts (divided by longitude 60°W) were mapped by entirely different groups of geologists, so the differences evident might be more apparent than real...... 205 Figure 11.10. Mapping in the eastern half of Mealy Mountains intrusive suite ...... 207 Figure 11.11. Names used in text refer to various parts of the MMIS ...... 208 Figure 11.12. Primary igneous layering in Kenemich, Etagualet and Bow Tie units ...... 210 Figure 11.13. Location of orthopyroxene megacrysts and granitic pods in MMIS...... 212 Figure 11.14. Distribution of monzonite dykes and enclaves in monzonite in MMIS ...... 221 Figure 12.1. Late Labradorian granitoid rocks not addressed in previous chapter (named units) ...... 230 Figure 12.2. Mount Benedict Intrusive Suite and Jeanette Bay quartz syenite. The spatially related Pamiulik Point mafic intrusion was addressed in the previous chapter ...... 231 Figure 12.3. Double Mer pluton...... 236 Figure 12.4. Snooks Cove granitoid intrusion and Pottles Cove Head suite ...... 237 Figure 12.5. Cartwright intrusive suite...... 239 Figure 12.6. Hawke Bay complex and Cape Bluff Pond granitoid intrusions...... 242 Figure 12.7. Paradise Arm pluton and The Backway megacrystic granitoid belt. Inset shows how the two units may be related, by restoring to pre-40-km-dextral-fault configuration ...... 245 Figure 12.8. Middle Eagle River pluton. Boundaries and names of four 1:100 000-scale map regions indicated ...... 248

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Figure 13.1. Distribution and nature of supracrustal rocks in the Pinware terrane, also showing their subdivision into Upper St. Augustin River and Henley Harbour districts ...... 252 Figure 13.2. Details of distribution and nature of supracrustal rocks in the Upper St. Augustin River district and U–Pb geochronological results ...... 254 Figure 13.3. Details of distribution and nature of supracrustal rocks in the Henley Harbour district and U–Pb geochronological results ...... 259 Figure 13.4. Distribution of some key minerals in rocks interpreted to have either a felsic volcanic or arenaceous protolith in the Henley Harbour district ...... 262 Figure 13.5. Distribution of some key minerals in pelitic rocks in the Henley Harbour district ...... 267 Figure 13.6. Distribution of some key minerals in calc-silicate rocks in the Henley Harbour district ...... 271 Figure 13.7. Distribution of granitoid rocks in the Pinware terrane. Both late Paleoproterozoic and Mesoproterozoic granitoid rocks are included (Unit PM)...... 273 Figure 13.8. Locations mentioned in section on Pinware terrane foliated and gneissic granitoid rocks ...... 273 Figure 13.9. Map enlargement of Lodge Bay area...... 284 Figure 13.10. Selected whole-rock geochemical variation diagrams attempting to discriminate between Labradorian and Pinwarian granitoid rocks in the Pinware terrane ...... 291 Figure 13.11. Variation in Rb + Y + Nb in Pinware terrane foliated and gneissic granitoid rocks, carrying the implication that the low and high Rb + Y + Nb categories correlate with Labradorian and Pinwarian granitoid rocks, respectively ...... 292 Figure 13.12. Distribution of Unit PM mafic rocks in the Pinware terrane. Both late Paleoproterozoic and Mesoproterozoic rocks are included ...... 293

Figure 14.1. Distribution of Unit M1 ultramafic, mafic and anorthositic rocks at the Pinware–Mealy Mountains terrane boundary ...... 301 Figure 14.2. Upper Paradise intrusive suite (monzonite–granite). Potentially related mafic to anorthositic rocks shown in grey ...... 313 Figure 14.3. Pinwarian activity north of Pinware terrane identified by U–Pb geochronological data ...... 318 Figure 15.1. Distribution of Michael gabbro. Geochronological results also shown; U–Pb and Sm–Nd sample sites labelled...... 322 Figure 15.2. Metamorphic zones defined on the basis of mineral assemblages in Michael gabbro ...... 325 Figure 15.3. Michael gabbro major- and trace-element geochemical variation diagrams. Red circles –

high-P2O5 group; blue circles – low-P2O5 group. Open circles are from the author’s database; filled circles are samples re-analyzed by R.F. Emslie and N. Devereaux (and for which Sm–Nd isotopic data are also available)...... 328 Figure 15.4. Michael gabbro trace-element petrotectonic discrimination diagrams ...... 329

Figure 15.5. Michael gabbro showing distribution of high-P2O5 (red circles) and low-P2O5 (blue circles) groups. Filled circles are sites for which Sm–Nd isotopic data are also available ...... 330 Figure 15.6. Upper Paradise River mafic dyke(?) localities (black circles) and suggested dyke trend (dashed lines). For geographic reference, grey background represents Upper Paradise River intrusive suite and Kyfanan Lake layered mafic intrusion ...... 332 Figure 15.7. Mokami Hill granitoid intrusion location. See text for reference to other features also shown ...... 333 Figure 16.1. Distribution of supracrustal rocks of the Road Belt, MT Belt and South Belt in the Fox Harbour area identified by Search Minerals Inc. (Miller, 2015) ...... 335 Figure 16.2. Upper North River granitoid intrusion...... 339 Figure 16.3. Distribution of Mealy dykes, Upper Paradise River dykes(?) and other potentially correlative minor mafic intrusions ...... 341 Figure 16.4. Stereographic plot for the Mealy dykes. Maximum: strike 247°/76°N...... 342 Figure 16.5. Lithogeochemical characteristics of the Mealy dykes – part 1 ...... 343 Figure 16.6. Lithogeochemical characteristics of the Mealy dykes – part 2 ...... 344 Figure 16.7. Battle Island geological features and geochronological sites ...... 347 Figure 17.1. Gilbert Bay granite, peripheral minor granitic intrusions, and Gilbert Bay(?) monzogabbronorite ...... 351

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Figure 17.2. Aillik mafic dyke correlative(?). Inset shows location of Aillik dykes...... 354 Figure 17.3. Early and late syn-Grenvillian intrusive and metamorphic zircon and monazite ages ...... 355 Figure 17.4. ‘Fold-Test’ intrusions, so-called because, by ascertaining if bodies of similar-looking K- feldspar megacrystic granitoid rocks correlate on either side of the fold, then the existence of the fold is demonstrated and a maximum age for folding determined. Inset illustrates (simplified) how present outcrop distribution could be achieved through differing deformation response on opposite limbs of a crescent-shaped body...... 357 Figure 17.5. Late syn-Grenvillian and early post-Grenvillian intrusions in the Pinware terrane ...... 360 Figure 17.6. Early post-Grenvillian mafic dykes; regional distribution, names and ages...... 375 Figure 17.7. Spatial relationship between L’Anse-au-Diable mafic dykes and Red Bay gabbronorite ...... 376 Figure 17.8. Some lithogeochemical features of the L’Anse-au-Diable, York Point, Gilbert Bay and Upper St. Lewis River mafic dykes...... 381 Figure 17.9. Further lithogeochemical characteristics of late Grenvillian mafic dykes (L’Anse-au- Diable, York Point and Gilbert Bay) and contrast with Phanerozoic mafic dykes (Sandwich Bay, Norman Bay, Charlottetown Road and Battle Harbour). See Chapter 19 for latter aspect ...... 382 Figure 17.10. Late post-Grenvillian granitoid intrusions; regional distribution, names and ages...... 383 Figure 17.11. A, B. Selected pre- and syn-Grenvillian granitoid intrusions in Y + Nb vs. Rb and Y vs. Nb space, C, D. Early- and late-post-Grenvillian granitoid intrusions in Y + Nb vs. Rb and Y vs. Nb space. Shaded boxes distinguish early post-Grenvillian dates...... 408 Figure 18.1. Double Mer Formation, inferred correlative rocks including clastic dykes, and related faults. Inset shows distribution of lower Labrador Group (Bateau and Lighthouse Cove formations) ...... 410 Figure 18.2. Long Range dykes, quartz veins and carbonate veins...... 421 Figure 18.3. Distribution of K-feldspar in Long Range dykes ...... 431 Figure 18.4. Lithogeochemical characteristics of the Long Range dykes ...... 432 Figure 19.1. Lighthouse Cove, Bateau, Bradore and Forteau formations ...... 437 Figure 19.2. Phanerozoic mafic dykes (Sandwich Bay, Norman Bay, Battle Harbour and Charlottetown Road dykes) ...... 439 Figure 19.3. Lithogeochemical characteristics of the Sandwich Bay, Norman Bay, Charlottetown Road and Battle Harbour mafic dykes ...... 441 Figure 20.1. Structural fabrics in the Cape Harrison domain, Makkovik Province...... 444 Figure 20.2. Makkovik Province reconstruction after 18 km of dextral displacement on Adlavik Brook– Tukialik Bay faults removed ...... 445 Figure 20.3. Planar structures in the Groswater Bay, Hawke River and Lake Melville terranes ...... 447 Figure 20.4. Linear structures in the Groswater Bay, Hawke River and Lake Melville terranes ...... 448 Figure 20.5. Structural data and interpretation in the area north of Double Mer ...... 450 Figure 20.6. Structural data and interpretation in the Rigolet district ...... 451 Figure 20.7. Structural data and interpretation at the southeast end of the Lake Melville terrane ...... 455 Figure 20.8. Planar structures and interpretation in the Mealy Mountains and Pinware terranes...... 456 Figure 20.9. Linear structures and interpretation in the Mealy Mountains and Pinware terranes...... 457 Figure 20.10. Structural data and interpretation in the southern part of the Pinware terrane ...... 461 Figure 20.11. Block diagrams illustrating mechanism for the formation of a basin due to change in ori- entation of major faults. A. Simplistic configuration that results in a wedge-shaped gap forming between two blocks down-faulted to the east, B. More realistic development of subsidiary faults both parallel to, and at a high angle to major faults. Giant quartz veins are linked to same cause ...... 463 Figure 20.12. Recent earthquakes in eastern Labrador: location, date and magnitude ...... 466 Figure 21.1. Distribution of sillimanite and kyanite in pelitic rocks in eastern Labrador...... 468 Figure 21.2. Distribution of cordierite and garnet in pelitic rocks in eastern Labrador ...... 469 Figure 21.3. Distribution of orthopyroxene, osumilite and sapphirine in pelitic rocks in eastern Labrador ...... 470

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Figure 21.4. Distribution of garnet, epidote and scapolite in calc-silicate supracrustal rocks ...... 472 Figure 21.5. Distribution of garnet and epidote in granitoid gneiss in eastern Labrador ...... 473 Figure 21.6. Distribution of clinopyroxene and orthopyroxene (igneous and metamorphic) in granitoid gneiss in eastern Labrador ...... 474 Figure 21.7. Distribution of perthite vs. microcline in granitoid gneiss in eastern Labrador...... 476 Figure 21.8. Distribution of orange-brown biotite vs. green biotite in granitoid gneiss in eastern Labrador ...... 477 Figure 21.9. Distribution of primary vs. relict igneous olivine and coronal vs. non-coronal (granoblastic) garnet in mafic rocks in eastern Labrador. Primary olivine represents lowest grade areas and granoblastic garnet the highest...... 478 Figure 21.10. Distribution of granoblastic orthopyroxene vs. double coronal orthopyroxene–amphibole (mantling olivine) in mafic rocks in eastern Labrador. This figure is complementary to Figure 21.8 ...... 479 Figure 21.11. Metamorphic pressure–temperature estimates in pelitic gneiss in eastern Labrador ...... 480 Figure 21.12. Geothermobarometric pressure–temperature determinations in pelitic gneiss: A. Plotted

according to Al2SiO5 polymorph present, B. Plotted according to assigned terrane...... 483 Figure 21.13. Model to explain metamorphic grade equivalence between Labradorian (or older) host rocks and Mesoproterozoic Michael gabbro that intrudes them, without involving post- Michael gabbro – pre-Grenvillian burial ...... 485 Figure 22.1. U–Pb geochronological data between 1900 and 1700 Ma for the Makkovik and Grenville provinces in eastern Labrador ...... 490 Figure 22.2. U–Pb geochronological data between 1700 and 1500 Ma for the Makkovik and Grenville provinces in eastern Labrador ...... 492 Figure 22.3. U–Pb geochronological data between 1500 and 1100 Ma for the Grenville Province in eastern Labrador...... 493 Figure 22.4. U–Pb geochronological data between 1100 and 900 Ma for the Makkovik and Grenville provinces in eastern Labrador ...... 494 Figure 22.5. Rb–Sr isotopic data. A. Initial ratios from regression analysis using regression age, B. Initial ratios for all samples using known U–Pb age or inferred emplacement age, C. Initial ratios using only known emplacement ages from same or nearby sample ...... 498 Figure 22.6. Sm–Nd epsilon vs. age plots. A. All samples, assuming emplacement age where not determined, B. Only samples for which emplacement age is known ...... 500

Figure 22.7. Depleted mantle (TDM) age-group distribution in eastern Labrador for felsic plutonic and volcanic rocks...... 502

Figure 22.8. Depleted mantle (TDM) age-group distribution in eastern Labrador for metasedimentary gneiss and mafic volcanic rocks ...... 503

Figure 22.9. Depleted mantle (TDM) age-group distribution in eastern Labrador for late Paleoproterozoic mafic plutonic and anorthositic rocks ...... 505

Figure 22.10. Depleted mantle (TDM) age-group distribution in eastern Labrador for Michael gabbro, Mealy dykes and Blanc-Sablon gabbro ...... 506

Figure 22.11. Depleted mantle (TDM) age-group distribution in eastern Labrador for Mesoproterozoic felsic plutonic rocks and minor felsic intrusions ...... 507 Figure 22.12. Ar–Ar and K–Ar biotite and hornblende geochronological data for the eastern Grenville Province. Location of 1000 Ma muscovite thermochron based on data shown by Gower (2003) ...... 508 Figure 23.1. Comparison of models for the tectonic evolution of the Makkovik Province ...... 512 Figure 23.2. Model for tectonic evolution in the Grenville Province in eastern Labrador during Labradorian orogenesis ...... 515 Figure 23.3. Model for tectonic evolution in eastern Laurentia during the Pinwarian orogeny and post- Pinwarian to pre-Grenvillian period ...... 517 Figure 23.4. Zipper model illustrating migration of a spreading centre under a cratonic block without concomitant subduction ...... 518

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Figure 23.5. Refined depiction of thermochrons in the eastern Grenville Province, including U–Pb data in addition to Ar–Ar and K–Ar data. A composite 1090 Ma thermochron (the time of the start of Grenvillian orogenesis) is included as the defining line between Grenvillian and pre-Grenvillian dates, but it can only be separated from the 1000 Ma thermochron in eastern Labrador...... 520 Figure 23.6. Thermochrons and Grenvillian features farther south in eastern Labrador showing complementary pattern...... 521 Figure 23.7. Regional Bouguer anomaly map for the eastern Grenville Province, also including some geochronological boundaries transferred from previous figure. High Bouguer anomalies – red; low Bouguer anomalies – blue ...... 522 Figure 23.8. Essence of Grenvillian indentor model configuration (from Gower et al., 2008a). The upper cross-section, based on the models of Beaumont et al. (2001, 2004), is incorporated into the lower block diagram depicting the Grenville Province in eastern Labrador to be the result of a colliding, overriding, indenting continent ...... 523 Figure A1.1. Data station spatial density, according to map region ...... 551

xxiv PLATES Page Plate 1.1. Selected physiographic features in southeast Labrador ...... 4 Plate 6.1. Examples of Aillik Group correlative rock types in the Cape Harrison domain (south of Burnt Island, ‘Little Double Island’, and Double Island areas) ...... 40 Plate 6.2. Examples of Aillik Group correlative rock types in the Cape Harrison domain (Deus Cape, Cape Harrison, and Tessialuk Lake areas) ...... 42 Plate 6.3. Examples of tonalite–granodiorite migmatitic gneiss of the Cape Harrison Metamorphic Suite and potential correlatives...... 47 Plate 6.4. White Bear Islands granulite complex granodiorite gneiss at dated locality (also showing crosscutting later mafic and felsic dykes). Modified from Krogh et al. (2002) ...... 49 Plate 6.5. Examples of late- to post-Makkovikian granitoid rocks in the Cape Harrison domain ...... 51 Plate 6.6. Tilt Cove alkali-feldspar syenite intruded by mafic–felsic composite dyke (CG79-118) ...... 63 Plate 6.7. Post-Makkovikian granitoid rocks in the Cape Harrison domain...... 65 Plate 7.1. Paleoproterozoic metasedimentary gneiss from the Double Mer region. Images A and B referred to in Section 7.3.1.2 and images C and D in Section 7.3.5.2 ...... 76 Plate 7.2. This rock is interpreted as a pelitic–psammitic metasediment in which graded bedding is preserved. The dark-grey, very fine-grained material marks the top of one graded unit that was then overlain by the basal creamy-grey, medium-grained material of the next unit. The sedimentary layers have been folded into an S-fold and show a well-defined axial-planar cleavage. The cleavage has been deflected, or is lacking, in the coarser grained material. The frac- ture cleavage has acted locally as small faults that have displaced bedding. Inset diagram pro- vides clarification (CG79-797) ...... 78 Plate 7.3. Some features of psammitic gneiss on Black Island, north side of Groswater Bay. The rocks are interpreted as part of the same unit as that shown in Figure 7.2 ...... 79 Plate 7.4. Rocks derived from supracrustal protoliths in the eastern Groswater Bay terrane...... 80 Plate 7.5. Mafic volcanic rocks from Paradise metasedimentary gneiss belt ...... 86 Plate 7.6. Calc-silicate rocks, quartzite–metachert and sulphide-rich material associated with mafic volcanic rocks in Paradise metasedimentary gneiss belt ...... 88 Plate 7.7. Pelitic gneiss in Paradise metasedimentary gneiss belt (PMGB) – part 1 ...... 90 Plate 7.8. Pelitic gneiss in Paradise metasedimentary gneiss belt (PMGB) – part 2 ...... 94 Plate 7.9. Garnetiferous and corundum-bearing pelitic gneiss in Lake Melville terrane ...... 101 Plate 7.10. Psammitic gneiss, quartzite and marble in Lake Melville terrane ...... 103 Plate 7.11. Pelitic gneiss in Mealy Mountains terrane ...... 114 Plate 8.1. Eagle River complex at two U–Pb geochronology sites...... 120 Plate 9.1. Alexis River anorthositic intrusion showing examples of very coarse grain size, igneous layering and graded layering ...... 125 Plate 9.2. Alexis River anorthositic intrusion in severely deformed state ...... 126 Plate 9.3. Features of ultramafic and mafic rocks assigned to be early Labradorian ...... 133 Plate 10.1. Key U–Pb geochronology locality in Cuff Island area illustrating intrusive and tectonized contacts between granodiorite gneiss and a mafic intrusion...... 139 Plate 10.2. Key U–Pb geochronology locality at Double Island illustrating field relationships with respect to younger units and detailed appearance of dated granitoid rocks (CG84-172)...... 140 Plate 10.3. Examples of folding in Groswater Bay terrane granitoid gneiss ...... 142 Plate 10.4. Incongruent melting and mafic dykes in Groswater Bay terrane granitoid gneiss...... 143 Plate 10.5. Key U–Pb geochronology locality at Red Island in Hawke River terrane. The later black dyke can be traced without interruption across the outcrop (CG84-436) ...... 147 Plate 10.6. Key U–Pb geochronology locality at Partridge Bay in the Hawke River terrane. The host gneissic quartz diorite was intruded by an early mafic dyke, followed by deformation and migmatization. The later mafic dyke postdated migmatization but was subsequently intruded by pegmatite. Inset is intended to better illustrate intrusive relationship of pegmatite into unmigmatized mafic dyke. *Actual dated pegmatite is farther west, but cuts the same unmigmatized mafic dyke (CG85-492)...... 148

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Plate 10.7. Composite key U–Pb geochronology locality at Shoal Bay in Hawke River terrane based on two sampling sites 1.8 km apart. The muscovite-bearing granite was dated at both localities and is correlated (CG85-532 and CG85-654)...... 149 Plate 10.8. Key U–Pb geochronology localities in Lake Melville terrane (Neveisik Island, Second Choice Lake and Mecklenburg Harbour) ...... 153 Plate 10.9. Some specific features of Lake Melville terrane granitoid gneiss ...... 155 Plate 10.10. Dated and undated gneissic granitoid rocks in the Mealy Mountains terrane ...... 161 Plate 11.1. Examples of mid- to late-Labradorian mafic intrusions in the Cape Harrison domain, Makkovik Province ...... 169 Plate 11.2. Features of the Little Grady Island layered gabbronorite–monzonite unit ...... 177 Plate 11.3. Features of Dykes River mafic intrusion, and net-veined mafic rock from southeast Sandwich Bay...... 182 Plate 11.4. Features of White Bear Arm complex (WBAC) and Sand Hill Big Pond (SHBP) mafic intrusion...... 191 Plate 11.5. White Bear Arm complex (WBAC), continued; and WBAC possible correlatives ...... 200 Plate 11.6. Some features of anorthositic members of the Mealy Mountains intrusive suite (MMIS) ...... 215 Plate 11.7. Some features of monzogranitic members of the Mealy Mountains intrusive suite (MMIS) ...... 218 Plate 12.1. Examples of late-Labradorian granitoid intrusions in the Cape Harrison domain (Makkovik Province), and Groswater Bay terrane...... 232 Plate 12.2. Examples of late-Labradorian granitoid intrusions in the Groswater Bay and Hawke River terranes...... 238 Plate 12.3. Examples of late-Labradorian granitoid intrusions in the Hawke River, Lake Melville and Mealy Mountains terranes ...... 246 Plate 13.1. Examples of rocks in the Upper St. Augustin River district having (or suspected to have) a sedimentary protolith ...... 256 Plate 13.2. Rocks in the Henley Harbour district interpreted to have volcanic protoliths ...... 260 Plate 13.3. Rocks in the Henley Harbour district interpreted to have an arenaceous protolith ...... 264 Plate 13.4. Rocks in the Henley Harbour district interpreted to have pelitic and calc-silicate protoliths ...... 269 Plate 13.5. Pinware terrane foliated and gneissic syenite and granite ...... 278 Plate 13.6. Pinware terrane foliated and gneissic quartz monzonite and granodiorite ...... 283 Plate 13.7. Pinware terrane foliated and gneissic quartz monzodiorite and K-feldspar megacrystic granitoid rocks ...... 287 Plate 13.8. Example of an unusual Pinware terrane amphibolite. Based on stained slabs and thin sections, the white areas are interpreted as recrystallized plagioclase phenocrysts ...... 295 Plate 13.9. Pinware terrane foliated and gneissic mafic rocks ...... 296 Plate 14.1. Pinware–Mealy Mountains terrane boundary mafic rocks. No-Name Lake mafic intrusion (A, B) and Upper Paradise River suite (C, D)...... 303 Plate 14.2. Pinware–Mealy Mountains terrane boundary mafic rocks; Kyfanan Lake layered mafic–anorthositic intrusion ...... 309 Plate 14.3. Upper Paradise River intrusive suite (monzonite–granite) ...... 314 Plate 15.1. Michael gabbro and Upper Paradise River mafic dyke. UPRIS – Upper Paradise River intrusive suite ...... 323 Plate 16.1. Examples of 1300–1200 Ma Mesoproterozoic units (Fox Harbour volcanic rocks; Upper North River granitoid intrusion; Mealy dykes; and Battle Island supracrustal rocks) ...... 337 Plate 17.1. Pre-Grenvillian Gilbert Bay granite and examples of dated syn-Grenvillian minor granitoid intrusions (WBAC – White Bear Arm complex). Zircon ages, where not specified otherwise ...... 352 Plate 17.2. Syn-Grenvillian ‘Fold-Test’ K-feldspar megacrystic granitoid unit and examples of dated syn- Grenvillian pegmatites...... 358 Plate 17.3. Late syn-Grenvillian alkali-feldspar syenite intrusions, and early post-Grenvillian mafic bodies...... 363 Plate 17.4. Early post-Grenvillian granitoid intrusions; Upper Beaver Brook and Picton Pond bodies ...... 369

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Plate 17.5. Early post-Grenvillian Lower Pinware River intrusion ...... 372 Plate 17.6. Early post-Grenvillian mafic dykes (L’Anse-au-Diable, York Point and Gilbert Bay types)...... 377 Plate 17.7. Examples of characteristic horizontal jointing commonplace in post-Grenvillian granitoid plutons ...... 384 Plate 17.8. Examples of post-Grenvillian granitoid plutons – part 1 ...... 385 Plate 17.9. Examples of post-Grenvillian granitoid plutons – part 2 ...... 392 Plate 17.10. Examples of post-Grenvillian granitoid plutons – part 3 ...... 397 Plate 17.11. Examples of post-Grenvillian granitoid plutons – part 4 ...... 400 Plate 18.1. Double Mer Formation in the Double Mer half graben and the Lake Melville graben ...... 411 Plate 18.2. Double Mer Formation correlative occurrences ...... 414 Plate 18.3. Clastic dykes; assumed correlative with Double Mer Formation ...... 416 Plate 18.4. Lower Labrador Group (Bateau and Lighthouse Cove formations) ...... 419 Plate 18.5. White Bear River estuary Long Range dyke; lithological character and minor associated dykes...... 422 Plate 18.6. Long Range dykes (Earl Island, Cartwright Island, Curlew Harbour and Cooper Island dykes) ...... 426 Plate 18.7. Examples of quartz veins and associated fault brecciation...... 434 Plate 19.1. Unconformity between Grenville Province crystalline basement and overlying Bradore Formation (CG93-193) ...... 438 Plate 19.2. Phanerozoic mafic dykes in eastern Labrador...... 440 Plate 20.1. Mylonitic structures and kinematic indicators in Groswater Bay and Hawke River terranes ...... 446 Plate 20.2. Rigolet thrust zone mylonite and recumbent folding in Lake Melville terrane ...... 452 Plate 20.3. Some structural features of the central and southeastern Lake Melville terrane ...... 454 Plate 20.4. Mylonite in the Pinware terrane ...... 460

xxvii PHOTOMICROGRAPHS Page Photomicrograph 6.1. Aillik Group correlatives in the Cape Harrison domain, Makkovik Province, and mylonitic rocks that may superficially resemble them...... 43 Photomicrograph 7.1. Mylonitized pelitic gneiss in Paradise metasedimentary gneiss belt, and pelitic gneiss enclaves in Earl Island intrusive suite, Hawke River terrane ...... 72 Photomicrograph 7.2. Features of Paradise metasedimentary gneiss belt muscovite- or cordierite-bearing pelitic gneiss ...... 91 Photomicrograph 7.3. Features of Paradise metasedimentary gneiss belt osumilite-bearing pelitic gneiss ...... 96 Photomicrograph 7.4. Lake Melville terrane calc-silicate rocks ...... 105 Photomicrograph 7.5. East Mealy metasedimentary gneiss...... 112 Photomicrograph 9.1. Metamorphic reactions in Alexis River anorthositic intrusion...... 128 Photomicrograph 10.1. Allanite and epidote in early Labradorian granitoid rocks in the Groswater Bay and Hawke River terranes...... 145 Photomicrograph 10.2. Some features of garnet in Lake Melville terrane granitoid rocks...... 156 Photomicrograph 11.1. Some features of White Bear Arm complex...... 198 Photomicrograph 11.2. High-grade metamorphic reactions in Labradorian mafic rocks ...... 202 Photomicrograph 12.1. Some features of late Labradorian granitoid rocks...... 233 Photomicrograph 13.1. Pinware terrane supracrustal rocks in the Henley Harbour district...... 253 Photomicrograph 14.1. Examples of Pinware–Mealy Mountains terrane boundary mafic rocks ...... 304 Photomicrograph 15.1. Examples of Early to Middle Mesoproterozoic (1460–1350 Ma) units...... 331 Photomicrograph 16.1. Examples of Middle Mesoproterozoic (1350–1200 Ma) units...... 338 Photomicrograph 17.1. Examples of late syn-Grenvillian nepheline-bearing syenite intrusions ...... 364 Photomicrograph 17.2. Examples of early post-Grenvillian major intrusions...... 367 Photomicrograph 17.3. Early post-Grenvillian mafic dykes ...... 378 Photomicrograph 18.1. Neoproterozoic supracrustal rocks ...... 417 Photomicrograph 18.2. Long Range major dykes ...... 424

xxviii TABLES Page Table 7.1 Sm–Nd isotopic data for metasedimentary gneiss in eastern Labrador ...... 71 Table 10.1. Geological history of Earl Island intrusive suite based on field relationships, minor intrusions and U–Pb dating at four key localities...... 146 Table 10.2. Sm–Nd isotopic data for the Earl Island intrusive suite...... 148 Table 11.1. Mafic dykes related to the Grady Island mafic intrusion...... 177 Table 11.2. Metamorphosed mafic dykes from the Groswater Bay terrane ...... 181 Table 11.3. Ar–Ar data for metamorphosed mafic dykes intruding the Earl Island intrusive suite ...... 185 Table 11.4. Metamorphosed mafic dykes (amphibolite) intruding the Earl Island intrusive suite...... 185 Table 11.5. Progressive mineralogical changes in White Bear Arm complex ...... 196 Table 11.6 Metamorphosed mafic dykes in the White Bear Arm complex ...... 199 Table 13.1. Field/slab names vs. names based on thin section examination...... 274 Table 13.2. Labradorian and Pinwarian U–Pb ages of foliated to gneissic granitoid rocks from the Pinware terrane ...... 275 Table 19.1. Norman Bay dykes ...... 439 Table 20.1. Recent earthquakes in eastern Labrador...... 465 Table 22.1. Units in eastern Labrador for which Rb–Sr isochrons or errorchrons have been reported ...... 497 Table A1.1. Summary of number of data stations, area of map, and data-station density for each map region in eastern Labrador ...... 550 Table A1.2. Aerial photographic coverage for eastern Labrador...... 553 Table A1.3. Correlation between U–Pb geochronology samples and whole-rock geochemical samples analyzed by Schärer (1991) ...... 559

xxix

ABSTRACT

This report, in conjunction with already published 1:100 000-scale geological maps, addresses the regional geology of the eastern parts of the Makkovik and Grenville provinces in Labrador, Canada.

The Makkovik Province represents the remnants of a former Paleoproterozoic accretionary orogen that developed on the southern flank of pre-Makkovikian Laurentia, mostly between 1900 and 1790 Ma. It comprises three structural domains, namely: i) the Kaipokok domain in the west, ii) the Aillik domain in the centre, and iii) the Cape Harrison domain in the east. Only the Cape Harrison domain is considered in this report. It includes remnants of Aillik Group 1855 Ma felsic volcanic rocks, but mostly consists of various Paleoproterozoic granitoid and gneissic rocks, namely the 1840 Ma Deus Cape granitoid, the 1820–1790 Ma Numok and related intrusive suites, the 1720 Ma Strawberry Intrusive Suite, and late Paleoproterozoic (1650 Ma) plutons.

The Grenville Province in eastern Labrador comprises late Paleoproterozoic and Mesoproterozoic rocks that formed during multiple orogenic events between ca. 1810 and 950 Ma. Six stages of geological development can be identified, namely: i) ‘Eagle River’ (late Makkovikian correlative) orogenesis (1810–1775 Ma), ii) Labradorian orogenesis (1710–1600 Ma), iii) Pinwarian orogenesis (1520–1460 Ma), iv) Post-Pinwarian–Pre-Grenvillian events (1460–1090 Ma), v) Grenvillian orogenesis followed by late- to post-Grenvillian events (1090–985 Ma; 985–920 Ma), and vi) Neoproterozoic and Phanerozoic events. The Eagle River, Labradorian, Pinwarian and Grenvillian orogenies were active-margin accretionary events, whereas the Grenvillian orogeny represents a continent–continent collision, which also terminated active Proterozoic accretionary tectonism in this region. The Grenville Province in eastern Labrador is subdivided into five terranes, which are, from north to south, Groswater Bay terrane, Hawke River terrane, Lake Melville terrane, Mealy Mountains terrane, and Pinware terrane. These have most geological significance in a Grenvillian context, but are referenced in a geographical sense when refer- ring to earlier rocks.

Rocks formed during the Eagle River orogeny can be divided into granitoid units and metasedimentary gneiss. The granitoid rocks have 1810–1775 Ma ages and clearly established the existence of a magmatic event in the Grenville Province well before Labradorian orogenesis. It was coeval with, or partially slightly younger than, the Numok intrusive event in the eastern Makkovik Province. The metasedimentary gneiss protolith was overwhelmingly pelitic, but associated rocks include psammitic gneiss, quartzite–metachert, mafic volcanic rocks, and rocks derived from calcareous protoliths. The depositional age of the metasedimentary gneiss remains uncertain, but is argued to have been between 1810 Ma and 1770 Ma.

Labradorian orogenesis in the eastern Grenville Province entailed an evolving series of events reflecting accretion of an outboard arc. The Labradorian orogeny has, traditionally, been defined as commencing at 1710 Ma, but scattered 1740–1700 Ma dates from the Groswater Bay terrane suggest greater affinity with the Strawberry Intrusive Suite in the Makkovik Province than hitherto supposed. There may have been a hiatus in activity between 1705 and 1680 Ma, after which volumi- nous Labradorian calc-alkaline magmatism occurred (1680–1655 Ma). Deformation and metamorphism were concentrated between 1665 and 1655 Ma, followed by a change in tectonic conditions, heralding the start of Trans-Labradorian magmatism (1655–1645 Ma). Post-Trans-Labradorian magmatism involved emplacement of trimodal mafic–anorthositic–monzogranitic rocks. Both time range and composition of trimodal magmatic products overlap with those of the preceding Trans- Labradorian magmatism (1655–1625 Ma), and were accompanied by deformation and metamorphism between 1645 and 1625 Ma. Late Labradorian events, between 1625 and 1600 Ma, involved the emplacement of minor granitic intrusions and sporadic, diverse, and dwindling metamorphism–deformational activity.

The key feature that characterizes dated Pinwarian magmatism (1520–1460 Ma) is an overwhelmingly granitic (sensu stricto) character. Large bodies are confined to the southern part of the eastern Grenville Province, with only minor Pinwarian felsic magmatism farther north. In addition to widespread granitic magmatism, Pinwarian activity also involved metamorphism and deformation. The Pinwarian event is interpreted as reflecting a continental-margin arc over a north-dipping subduction zone.

Post-Pinwarian–Pre-Grenvillian events (1460–1090 Ma) do not involve orogenesis. Early post-Pinwarian–pre- Grenvillian activity (1460–1350 Ma) in eastern Labrador is represented by the Michael gabbro (1450–1425 Ma) and the 1417 Ma Mokami Hill quartz monzonite in the Groswater Bay terrane. The middle phase (1350–1290 Ma), in eastern Labrador, is

xxxi marked by the 1296 Ma Upper North River granite and coeval felsic volcanism, both found in the Lake Melville terrane. The late phase (1290–1230 Ma) in eastern Labrador is exemplified by the 1250 Ma Mealy dykes in the Mealy Mountains terrane. The lead-up to the start of Grenvillian orogenesis in eastern Laurentia was largely a period of inactivity, but is signposted in eastern Labrador by the deposition of the Battle Island supracrustal rocks and the emplacement of the Gilbert Bay granite.

Grenvillian orogenesis in the eastern Grenville Province extended from 1090 to 985 Ma, followed by late- to post- Grenvillian events between 985 and 920 Ma. It is interpreted in terms of a tectonic indentor model. In the Groswater Bay and Hawke River terranes, Grenvillian orogenesis was modest and unaccompanied by magmatism. Pre-Grenvillian titanite ages are commonly preserved. The Lake Melville terrane was the scene of the most severe Grenvillian activity, being characterized by northwest-verging thrusting north of Lake Melville and dextral strike‒slip transposition from Lake Melville to the southern Labrador coast. Deformation and metamorphism were associated with emplacement of minor granitoid intrusions ‒ at least, during the early stages of activity. Orogenesis started in the Lake Melville terrane at 1090 Ma, much earlier than in the other terranes (ca. 1050 Ma). The Mealy Mountains terrane also experienced mild Grenvillian orogenesis. Magmatism was very minor, except in southern parts of the terrane, which were affected by late- to post-Grenvillian granitoid pluton emplacement. The Pinware terrane, in contrast to the other terranes, was characterized by extensive granitoid pluton emplacement accompanied by moderate- to high-grade metamorphism, commencing at ca. 1040 Ma, and continuing until 985 Ma, at which time metamorphism and deformation declined significantly. Later Grenvillian events are divided into two groups. The older event (985–975 Ma) included alkalic mafic dyking and anorthositic‒mafic‒alkalic magmatism, whereas the younger event (975–955 Ma) was one of monzonitic, syenitic and granitic magmatism. The first clearly developed into the second without any hiatus, but there are sufficient time–compositional contrasts to distinguish them.

Late Neoproterozoic events are related to the rifting and drifting phases of the opening of Iapetus Ocean. Rifting was marked in the region by the emplacement of the 615 Ma Long Range dykes, huge quartz veins, deposition of the Double Mer Formation in the Lake Melville Rift System and Sandwich Bay graben, deposition of the Bateau Formation, and extrusion of the Lighthouse Cove mafic volcanic rocks. The start of the drifting phase in the early Phanerozoic is marked by flooding of the ancient Laurentian margin, as indicated by deposition of ferruginous clastic and mixed clastic–carbonate of the Bradore and Forteau formations. At least two, and possibly three, mafic dyke-emplacement events of uncertain specific age occurred later during the Phanerozoic.

xxxii ACKNOWLEDGMENTS

Acknowledgment is due to my former field assistants; all of them hard working, enthusiastic and conscientious – they made a huge contribution. They are as follows: Robin Burry (1979); Randy Gillespie, Lester Green, Andy Hopkins, Nath Noel, Max Roberts and Mike Tubrett (1980); John Blagdon, Greg Finn, Helen Norman, Victor Owen, Anne Walsh and Gerry Whelan (1981); Peter King and Tony Power (1983); Celeste O’Flaherty, Nath Noel, Janet O’Neill, John Smyth, Tim van Nostrand and Michel Wawrzkow (1984); Loretta Crisby, Peter Jeon, Bernadine Lawler, Gordon McRoberts, Steve Prevec and Tim van Nostrand (1985); Dennis Brown, Janet Dunphy, Mark Harris, Sigrid Neuland, Mark Newman and John Smyth (1986); Campbell Churchill, Joan Dicks, John Smyth, Glenda Stratton, Tim van Nostrand and Gale Wiseman (1987); Joe Anderson, Dean Fraser, Vince Peckham, Craig Scott and Tim van Nostrand (1992); Dawn Evans-Lamswood, Phyllis McCrindle, Wayne Mitchelmore and Tim van Nostrand (1993); Gary Bugden, Andy Churchill and Tim van Nostrand (1995; shared with colleague Ges Nunn); John Hinchey (1997); Craig Rowe (1998); Byron Malloy and Steve Power (1999); Wanda Maddox and Diane Mitchinson (2000). Also acknowledged are assistants employed on projects conducted by colleagues in the region. Al Doherty was accompanied by Bill Collins (1979); Philippe Erdmer was accompanied by Glenn Bursey, Chris Pinsent, Tony Power and Mark Wilson (1982); Tim van Nostrand was accompanied by Joe Anderson, Mark Blake, Don Dunphy, Darrell Eddy and Bob Patey (1991). Also appreciated are the contributions of students in the office, Nicole Deveraux and Leah Powers.

The contributions of students who have carried out university thesis studies in the region that were connected in some manner with the mapping deserve mention. These are Victor Owen (1985, Ph.D.), Celeste O'Flaherty (1986, B.Sc.), Steve Prevec (1987, M.Sc.), Tim van Nostrand (1988, M.Sc.). Other student theses relevant to the region were completed by Rebecca Hewitson (2010, M.Sc.), Nicole Devereaux (2011, B.Sc.), Rebecca (formerly Hewitson) Moumblow (2014, Ph.D.), James Haley (2014, M.Sc.), Grant Bybee (2013, Ph.D.), Chris Spencer (2014, Ph.D.) and Chris Rogers (2017, Ph.D.).

The formidable task of piloting this report through to publication was accomplished by Chris Pereira (text editing), Des Walsh (copy editing), Joanne Rooney (desktop publishing) and Kim Morgan (figure editing). Database editing by Pauline Honarvar and GIS map editing by Neil Stapleton were both expertly and thoroughly carried out. An enormous debt of grati- tude is owed to all.

xxxiii