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TitreGeology of Lower Ordovician fossiliferous strata between Virgin Arm and Squid Cove, New World Island, Newfoundland
TéléchargerTéléchargement (publication entière)
AuteurHorne, G S
SourceGeology of Lower Ordovician fossiliferous strata between Virgin Arm and Squid Cove, New World Island, Newfoundland; Early Ordovician (Late Arenig) brachiopods from Virgin Arm, New World Island, Newfoundland; par Horne, G S; Commission géologique du Canada, Bulletin 261, 1976 p. 1-9, https://doi.org/10.4095/123970 (Accès ouvert)
Année1976
ÉditeurMinistère de l'énergie, des mines et des ressources Canada
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.4095/123970
Mediapapier; en ligne; numérique
Référence reliéeCette publication est contenue dans Horne, G S; Neuman, R B; (1976). Geology of Lower Ordovician fossiliferous strata between Virgin Arm and Squid Cove, New World Island, Newfoundland; Early Ordovician (Late Arenig) brachiopods from Virgin Arm, New World Island, Newfoundland, Commission géologique du Canada, Bulletin no. 261
Formatspdf
ProvinceTerre-Neuve-et-Labrador
SNRC2E/09; 2E/10
Lat/Long OENS -55.0000 -54.0000 49.7500 49.5000
Sujetsgéologie du substratum rocheux; lithologie; roches ignées; roches volcaniques; volcanoclastique; basaltes; tufs volcaniques; roches sédimentaires; calcaires; argilites; pélites; grauwackes; fossiles; cadre tectonique; marges plaques; zones de subduction; arcs insulaires; paléogéographie; milieu sédimentaire; milieux marins; milieu côtièr; corrélations stratigraphiques; caractéristiques structurales; failles; Faille de Cobbs Arm ; Formation de Goldson ; Groupe de Summerford ; Faille de Virgin-Village ; Graptolites; paléontologie; géologie régional; Phanérozoïque; Paléozoïque; Silurien; Ordovicien
Illustrationslocation maps; geological sketch maps; composite sections; stratigraphic sections; photographs; schematic cross-sections
Diffusé1977 03 01; 2017 01 12
Résumé(disponible en anglais seulement)
Early Ordovician brachiopods, trilobites and other fossils occur in volcaniclastic strata of the Cobbs Arm Sequence exposed along the north-central coast of New World Island at the northern end of Newfoundland's central volcanic belt. The stratigraphic succession has been interpreted as representing the seaward margin of a volcanic island-arc system that was generated by the subductive closure of a hypothetical early Paleozoic seaway.
A pile of Lower and Middle Ordovician submarine basaltic extrusives 300 m thick contains thin and discontinuous beds of calcareous tuff and volcanogenic elastics with shallow-marine fossil assemblages. The volcanics are succeeded by about I 0 m of fossiliferous Middle Ordovician limestone, which is overlain by approximately 75 m of black, graptolitic Upper Ordovician argillite. The upper part of the succession consists of 50 m of penecontemporaneously distorted pelitic strata that gradationally coarsen upwards into well stratified greywacke of Late Ordovician and Early Silurian age.
The stratigraphic sequence may be correlated with both the Summerford Group to the southwest and the Hillgrade Group to the northeast. The faunas are characterized by peculiar generic associations, some of which are unknown elsewhere. Paleogeographic interpretations suggest the faunas inhabited coastal waters surrounding volcanic isles within an Early Ordovician ocean.
GEOSCAN ID123970