5th International Symposium on the Silurian System ! 5th Annual Meeting of the IGCP 591 - The Lower to Middle Paleozoic Revolution ! Gaspe, July 3 – 7, 2015! Pre-Conference Excursion! THE LOWER PALEOZOIC ROCKS ! OF THE GASPÉ PENINSULA! ! M. Malo1, D. Lavoie2, and D. Brisebois3 ! ! with the participation of! Richard Cloutier4! ! ! 1 Institut national de la recherche scientifique – ETE / 2 Geological Survey of Canada (Québec Division) / 3 Pétrolia / 4 Université du Québec à Rimouski! THE LOWER PALEOZOIC ROCKS OF THE GASPÉ PENINSULA Michel Malo1, Denis Lavoie2, and Daniel Brisebois3 with the participation of Richard Cloutier4 1 Institut national de la recherche scientifique, Eau Terre Environnement, 490, rue de la Couronne, Québec, QC, G1K 9A9 2 Geological Survey of Canada 490, rue de la Couronne, Québec, QC, G1K 9A9 3 Pétrolia, 305, boul. Charest Est, 10e étage Québec, QC, G1K 3H3 4 Université du Québec à Rimouski, Département de Biologie, Chimie et Géographie 300, allée des Ursulines, Rimouski, QC, G5L 3A1 Pre-conference excursion July 3 – July 7, 2015 IGCP 591: The Early to Middle Paleozoic Revolution 5th Annual Meeting July 8-11, 2015 Québec, Canada TABLE OF CONTENT PREAMBLE ................................................................................................................................... 1 FROM IAPETAN RIFT TO ACADIAN FORELAND ................................................................. 2 1. INTRODUCTION ................................................................................................................. 3 2. REGIONAL GEOLOGICAL SETTING .............................................................................. 3 3. TECTONOSTRATIGRAPHIC DOMAINS OF THE APPALACHIANS ........................... 5 4. THE TACONIAN-DEFORMED BASINS – THE HUMBER ZONE ................................. 6 4.1. End rift–early drift ........................................................................................................ 10 4.1.1. The St. Lawrence Promontory (western Newfoundland) ...................................... 10 4.1.2. The Québec Reentrant (Eastern Québec) .............................................................. 12 4.2. The passive margin ....................................................................................................... 16 4.2.1. The St. Lawrence Promontory (western Newfoundland) ...................................... 17 4.2.2. The Québec Reentrant (Eastern Québec) .............................................................. 18 4.2.3. Correlation Newfoundland – Québec .................................................................... 18 4.3. A regional sea-level scenario for the Lower Paleozoic end-rift and passive margin ... 21 4.4. The Taconian foreland basin ........................................................................................ 23 4.4.1. The St. Lawrence Promontory (Western Newfoundland) ..................................... 23 4.4.2. The Québec Reentrant (Eastern Québec) .............................................................. 24 4.4.3. Correlation Newfoundland – Québec .................................................................... 25 5. THE POST-TACONIAN TO ACADIAN BASINS ........................................................... 26 5.1. Newfoundland .............................................................................................................. 28 5.1.1. The Clam Bank Belt .............................................................................................. 28 5.1.2. The Salinic Unconformity and Orogeny in western Newfoundland ..................... 29 5.2. Continental eastern Canada .......................................................................................... 30 5.2.1. Late Ordovician – Early Silurian (the R1 event) ................................................... 33 5.2.2. Early Silurian – Late Silurian (the T1 - R2 events) ............................................... 34 5.2.3. Latest Silurian – Middle Devonian (the T2-R3 events) ........................................ 35 5.2.4. The Salinic Unconformity and Disturbance in the Gaspé Belt ............................. 36 5.3. Paleogeographic reconstruction of the post-Taconian basins ...................................... 40 5.3.1. Latest Pridolian / Earliest Lochkovian (Figure 20) ............................................... 40 5.3.2. Middle Lochkovian (Figure 21) ............................................................................ 41 iv 5.3.3. Pragian – Early Emsian (Figure 22) ...................................................................... 42 6. THE SEA LEVEL RECORD IN THE LOWER TO MIDDLE PALEOZOIC APPALACHIANS IN EASTERN CANADA: EUSTASY VERSUS TECTONISM ........ 43 6.1. Early Cambrian – Late Ordovician Humber Appalachians.......................................... 44 6.2. Latest Ordovician to Middle Devonian Acadian basins ............................................... 45 7. HYDROCARBON POTENTIAL OF THE APPALACHIAN BASINS ............................ 46 7.1. Lower Paleozoic Belts – Humber Zone in Québec ...................................................... 46 7.2. Lower Paleozoic Belts – Humber Zone in Western Newfoundland ............................ 46 7.3. Lower Paleozoic Belts – Gaspé Belt ............................................................................ 47 FIELDTRIP................................................................................................................................... 49 8. OVERVIEW FOR DAY 1 AND DAY 2 (STOPS 1.1 to 2.2) CAMBRIAN-ORDOVICIAN ROCKS OF THE EXTERNAL HUMBER ZONE ............................................................. 49 8.1. Introduction .................................................................................................................. 49 8.2. Stratigraphy .................................................................................................................. 51 8.2.1. The Lower Cambrian siliciclastics and limestone conglomerate (Stops 1.1 and 1.2) ......................................................................................................................... 51 8.2.2. The Middle Cambrian fine-grained siliciclastics .................................................. 52 8.2.3. The Upper Cambrian-lowermost Ordovician sediments (Stop 1.3) ...................... 52 8.2.4. The Lower to Middle Ordovician fine-grained successions of siliciclastics and limestones .............................................................................................................. 53 8.2.5. The Ordovician foreland basin strata (Stops 2.1 and 2.2) ..................................... 53 9. OVERVIEW FOR DAY 2 (STOPS 2.3 and 2.4) AND DAYS 3 TO 5 SILURIAN- DEVONIAN ROCKS OF THE GASPÉ BELT IN THE GASPÉ PENINSULA ............... 54 9.1. Introduction .................................................................................................................. 54 9.2. Stratigraphy .................................................................................................................. 56 9.2.1. Southern Gaspé Belt - Aroostook-Percé anticlinorium and Chaleurs Bay synclinorium .......................................................................................................... 56 9.2.1.a. Basement of the southern Gaspé Belt ........................................................... 56 9.2.1.b. The Mictaw Group ........................................................................................ 57 9.2.1.c. The Honorat Group ....................................................................................... 58 9.2.1.d. The Matapédia Group (Stops 3.4 and 3.5) .................................................... 59 9.2.1.e. The Chaleurs Group (Stops 2.3, 3.3, 4.1 to 4.5) ........................................... 60 9.2.1.f. Units Related to the Gaspé Sandstones Group in the Ristigouche Syncline (Miguasha Museum stop).............................................................................. 68 v 9.3. Northern Gaspé Belt - Connecticut Valley-Gaspé synclinorium ................................. 69 9.3.1. Basement of the northern Gaspé Belt .................................................................... 70 9.3.1.a. The Upper Gaspé Limestones Group (UGL) (Stop 2.3). .............................. 70 9.3.1.b. Fortin Group.................................................................................................. 72 9.3.1.c. Gaspé Sandstones Group (Stop 2.4) ............................................................. 72 DAY 1 ........................................................................................................................................... 75 Cambrian-Ordovician Rock Sequence in the Bas-du-Fleuve Region – Québec to Matane ......... 75 STOP 1.1. - Cambrian sandstone, Saint-Nicolas Formation – Québec City – Pont Laporte ............................................................................................................................... 76 STOP 1.2. - Cambrian limestone conglomerate, Saint-Roch Group - L’Islet ..................... 78 STOP 1.3. - Cambrian conglomerate, Saint-Damase Formation - Saint-Simon-sur-Mer ... 83 DAY 2 ........................................................................................................................................... 85 Cambrian-Ordovician Rock Sequences in the Gaspé Peninsula – Matane to Rivière-au-Renard 85 STOP 2.1. - Turbidites of the Ordovician foreland basin, Tourelle Formation – Cap Sainte- Anne, Saint-Joachin-de-Tourelle