BEDROCK GEOLOGY OF THE CAPE ST. MARY’S PENINSULA, SOUTHWEST AVALON PENINSULA, NEWFOUNDLAND (INCLUDES PARTS OF NTS MAP SHEETS 1M/1, 1N/4, 1L/16 and 1K/13) Terence Patrick Fletcher Report 06-02 St. John’s, Newfoundland 2006 Department of Natural Resources Geological Survey COVER The Placentia Bay cliff section on the northern side of Hurricane Brook, south of St. Bride’s, shows the prominent pale limestones of the Smith Point Formation intervening between the mudstones of the Cuslett Member of the lower Bonavista Formation and those of the overlying Redland Cove Member of the Brigus Formation. The top layers of this marker limestone on the southwestern limb of the St. Bride’s Syncline contain the earliest trilobites found in this map area. Department of Natural Resources Geological Survey BEDROCK GEOLOGY OF THE CAPE ST. MARY’S PENINSULA, SOUTHWEST AVALON PENINSULA, NEWFOUNDLAND (INCLUDES PARTS OF NTS MAP SHEETS 1M/1, 1N/4, 1L/16 and 1K/13) Terence P. Fletcher Report 06-02 St. John’s, Newfoundland 2006 EDITING, LAYOUT AND CARTOGRAPHY Senior Geologist S.J. O’BRIEN Editor C.P.G. PEREIRA Graphic design, D. DOWNEY layout and J. ROONEY typesetting B. STRICKLAND Cartography D. LEONARD T. PALTANAVAGE T. SEARS Publications of the Geological Survey are available through the Geoscience Publications and Information Section, Geological Survey, Department of Natural Resources, P.O. Box 8700, St. John’s, NL, Canada, A1B 4J6. This publication is also available through the departmental website. Telephone: (709) 729-3159 Fax: (709) 729-4491 Geoscience Publications and Information Section (709) 729-3493 Geological Survey - Administration (709) 729-4270 Geological Survey E-mail: [email protected] Website: http://www.gov.nl.ca/mines&en/geosurv/ Author’s Address: Dr. Terence P. Fletcher Bowmont Cottage East Links Dunbar, East Lothian Scotland, UK EH42 1LT ISBN: 1-55146-031-9 NOTE The purchaser 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. DISCLAIMER The Geological Survey, a division of the Department of Natural Resources (the “authors and publishers”), retains the sole right to the original data and information found in any product produced. The authors and publishers assume no legal liability or responsibility for any alterations, changes or misrepresentations made by third parties with respect to these products or the original data. Furthermore, the Geological Survey assumes no liability with respect to digital reproductions or copies of orig- inal products or for derivative products made by third parties. Please consult with the Geological Survey in order to ensure originality and correctness of data and/or products. Recommended citation Fletcher, T.P. 2006: Bedrock geology of the Cape St. Mary’s Peninsula, southwest Avalon Peninsula, Newfoundland (incudes parts of NTS map sheets 1M/1, 1N/4, 1L/16 and 1K/13), Newfoundland. Government of Newfoundland and Labrador, Geological Survey, Department of Natural Resources, St. John’s, Report 06-02, 117 pages. CONTENTS Page ABSTRACT . xv INTRODUCTION . 1 LOCATION AND ACCESS . 1 PREVIOUS WORK . 1 PHYSIOGRAPHY. 5 REGIONAL GEOLOGY . 10 REVIEW . 10 NOMENCLATURE. 13 Ediacaran. 13 Cambrian. 13 DANTZIC SUPERGROUP . 15 Definition . 15 FORTUNE GROUP. 15 Definition . 15 ADEYTON GROUP . 15 Definition . 15 GEOLOGY OF THE CAPE ST. MARY’S PENINSULA. 17 EDIACARAN ROCKS . 17 MUSGRAVETOWN GROUP (UNITS 1 to 5) . 17 Definition . 17 Bull Arm Formation (Unit 1) . 18 Definition . 18 Distribution and Thickness . 18 Lithology . 18 Contact Relations. 18 Correlation . 18 Big Head Formation (Unit 2) . 19 Definition . 19 Distribution and Thickness . 19 Lithology . 20 Contact Relations. 20 Correlation . 21 Maturin Ponds Formation (Units 3a to 3c). 21 Definition . 21 False Cape Member (Unit 3a) . 21 Definition . 21 Distribution and Thickness. 21 Lithology . 21 Contact Relations . 21 Correlation . 22 Young’s Port Member (Unit 3b) . 22 Definition . 22 Distribution and Thickness. 22 Lithology . 23 Contact Relations . ..