Stratigraphy and sedimentology of Middle Cambrian to Lower Ordovician shallow water carbonate rocks, western Newfoundland

• Main Author: Levesque, Rene Joseph
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1977
• Subjects: Barrier Islands; East Arm; Hawke Bay; Hawkes; Hawkes Bay; Penguin Cove; Newfoundland
• Online Access: https://research.library.mun.ca/6906/; https://research.library.mun.ca/6906/1/ReneJosephLevesque.pdf; https://research.library.mun.ca/6906/3/ReneJosephLevesque.pdf

Detailed lithostratigraphic analysis and new fossil data have resulted in a revised and refined stratigraphic and sedimentologic framework for the autochthonous, Middle Cambrian to Lower Ordovician, shallow water sedimentary sequence in western Newfoundland. Study of five separate localities, spanning a distance of 285 km., indicates that much more of this 900 metre thick sequence Is of Cambrian age and much Less of Ordovician age than previously reported. -- The oldest units studied are of late Lower Cambrian age and can be recognized in three of the five localities where they are named the Degras Formation (at the Port-au-Port Peninsula), the Penguin Cove Formation (at Goose Arm), and the Hawke Bay Formation (at Bonne Bay). These thick-bedded, supermature, quartzose sandstones are interpreted to have formed as a system of barrier bars or beaches. -- An overlying succession of distinctive. Middle and Upper Cambrian, limestones, dolostones, and shales is recognized from Port-au-Port in the south to Hawkes Bay in the north. This succession is variously known as the March Point (revised) and overlying Petit Jardin (revised) Formations at Port-au-Port, the Wolf Brook (proposed) and overlying Blue Cliff (proposed) Formations at Goose Arm, the South Head (proposed) and overlying East Arm (revised) Formations at Bonne Bay, and the upper Hawke Bay Formation at Hawkes Bay. -- Middle and Upper Cambrian rocks are characterized by conspicuously cyclic, "high-energy" lithofacies and comprise two large scale sequences which repeat, in vertical succession, as many as three times: (I) thin-bedded sequences composed of flaser bedded limestone and shale intercalated with occasional beds of edgewise conglomerate, stromatolites, and oolite, interpreted as a mixed carbonate-sillciclastlc tidal flat and (2) thick-bedded sequences composed of intraformational conglomerate, in places oncolitic, cross-bedded oolite, and laminated, mud cracked calcilutite, interpreted as carbonate sand shoals or barrier islands. -- The succeeding Lower ...