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TitreFault reactivation during Mesozoic extension in eastern offshore Canada
Auteurde Voogd, B; Keen, C E; Kay, W A
SourceSeismic probing of continents and their margins; Tectonophysics vol 173, no 1-4, 1990 p. 567-580,
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 47688
ÉditeurElsevier BV
RéunionSeismic probing of Continents and their Margins; Canberra; Aus; 19880701; juillet 1-8, 1988
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceRégion extracotière de l'est
Lat/Long OENS -60.0000 -43.0000 52.0000 43.0000
Sujetslevés géophysiques; levés sismiques; marges continentales; failles; failles, chevauchement; failles normales; océanographie; déplacement; géologie structurale; géophysique; géologie marine; Mésozoïque
Illustrationssketch maps; seismic profiles
Résumé(disponible en anglais seulement)
New Seismic data are presented that document reactivation of a thrust fault as a normal fault. Four deep Seismic reflection profiles now straddle the Hibernia oil field region of the Grand Banks off eastern Canada. The profiles intersect each other near the western edge of the 22 km deep Jeanne d'Arc Basin, thereby giving a three-dimensional picture of basement structures. The basin-bounding fault which marks the eastern edge of the Bonavista platform appears to follow a pre-existing fault system. More precisely, the fault that bounds the Jeanne d'Arc Basin just north of Hibernia can be traced on the Seismic data along strike to the south, beneath the Bonavista platform, where it has not been reactivated. The Seismic data show that this feature was probably a Palaeozoic thrust fault. A laterally extensive Palaeozoic(?) basin occupies most of the Bonavista platform. The deeper part of the crust is quite reflective and is characterized by numerous, dipping reflective packages.

This detailed study of the Hibernia region suggests that the narrow elongated basins of the Grand Banks may have been formed within the reactivated hanging walls of older thrust sheets. Similar observations have been made for the Mesozoic extensional basins of the U.K. continental shelf. The pre-Mesozoic compressional structures documemed on the central Grand Banks lie along the Appalachian Orogen and may be of Variscan age.