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TitleEarly Silurian carbonate platforms in the Appalachian orogenic belt: the Sayabec-La Vieille formations of the Gaspé-Matapédia basin, Quebec
AuthorLavoie, D; Bourque, P -A; Héroux, Y
SourceCanadian Journal of Earth Sciences vol. 29, issue 4, 1992 p. 704-719, (Open Access)
LinksGIRGAB - Group Interuniversitaire de Recherches en Géodynamique et Analyse de Bassins
Alt SeriesEarth Sciences Sector, Contribution Series 2005586
Alt SeriesQuebec Department of Energy and Natural Resources, Contribution 91-5110-18
PublisherCanadian Science Publishing
Mediapaper; on-line; digital
File formatpdf
NTS22A; 22B
AreaGaspé Peninsula; Sainte-Anne-des-Monts; Lac Matapédia; Port-Daniel; New Richmond; Baie des Chaleurs; northern Appalachians
Lat/Long WENS -68.0000 -64.0000 49.0000 48.0000
Subjectsstratigraphy; sedimentology; Lower Silurian; Llandoverian; Wenlockian; carbonates; limestones; reefs; biological communities; laminites; stromatolites; oncolites; facies; depositional environment; mud flats; algae; sandstones; mudstones; conglomerates; calcarenites; calcilutites; dolomites; siltstones; shales; tuffs; subtidal environment; lagoons; nearshore environment; lithology; depositional history; paleogeography; sea level changes; regressions; transgressions; tectonic history; tectonic environments; sedimentation; Appalachian Province; Sayabec Formation; La Vieille Formation; Northern Outcrop Belt; Angers-Dugal outcrop belt; Chaleur Bay Synclinorium; Matapedia Lake Syncline; Maria fault block; Ristigouche Syncline; Gaspé Belt; Thrombolites; Metazoa; Corals; Bryozoans; Stromatoporoids; Brachiopods; Quebec Reentrant; St. Lawrence Promontory; Gaspe Basin; Matapedia Basin, N B; Salinian erosion; Ristigouche volcanics; Sayabec carbonate platform; Laforce carbonate sand body; La Vieille carbonate platform; peritidal environments; carbonate platforms; Pentamerid banks; boundstones; siliciclastics; volcanogenic facies; depositional belts; Phanerozoic; Paleozoic; Silurian
Illustrationssketch maps; stratigraphic correlations; stratigraphic charts; tables; photomicrographs; photographs; plots; block diagrams; aerial photographs; geochronological charts
ProgramNSERC Natural Sciences and Engineering Research Council of Canada
ProgramFCAR - Fonds pour la Formation de Chercheurs et l'Aide à la Recherche
AbstractThe coeval Early Silurian (late Llandoverian to late Wenlockian) Sayabec and La Vieille formations represent the first occurrence of shallow-water platformal limestones and reefs in the Paleozoic sequence of the Gaspé Belt of the northern Appalachians. Both units display very similar fades, representing laterally well-zoned, south-dipping carbonate platforms with four parallel depositional belts. These, from nearshore to offshore, are (i) a peritidal mud flat dominated by microbial communities (laminites, stromatolites, thrombolites, oncolites); (ii) a low knob reef rim built by skeletal metazoans (corals, bryozoans, stromatoporoids), skeletal calcareous algae, and microbial communities; (iii) a well-sorted lime sand belt; and (iv) a deeper water nodular lime mud belt supporting a tabulate and rugose coral, stromatoporoid, skeletal algae, and large-shelled brachiopod biota. The two platforms developed at the margin of the Quebec Reentrant and St. Lawrence Promontory in the Gaspé Belt of the northern Appalachian Orogen. It is not clear whether they were parts of a single continuous platform stretching along the northern margin of the Gaspé Belt or two separate platforms occupying distinct tectonic blocks. The development of the Sayabec and La Vieille platforms corresponds to the peak of the first shallowing phase in the Gaspé Belt after the Taconian orogeny. The platforms, with their reefs, grew during a period of sea-level stability from the earliest to late Wenlockian. The reefs were killed by an influx of deeper water siliciclastic sediments during a late Wenlockian transgression.