Mesozoic Extension and Styles of Basin Formation in Atlantic Canada
Published:January 01, 1989
A. J. Tankard, H. J. Welsink, 1989. "Mesozoic Extension and Styles of Basin Formation in Atlantic Canada", Extensional Tectonics and Stratigraphy of the North Atlantic Margins, A. J. Tankard, H. R. Balkwill
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The geometry and distribution of Mesozoic rift basins off Newfoundland and Nova Scotia are con-trolled by the interaction of tensional stress fields with pre-existing crustal structure. Reactivation of the structural boundary between the Avalon and Meguma terranes from the Middle Triassic to Early Cretaceous is expressed in a series ofsinistral strike- slip basins that contain spectacular diapiric structures. Different basin geometries characterize the terrane interiors. The basin-forming faults of the composite Scotian basin are long and sinuous. Large amounts of extension were accommodated by dip-slip and oblique-slip processes along a system of en echelon and intersecting faults and relay ramps. Ocean opening occurred in the Middle Jurassic after a single episode of extension. The Grand Banks and the Orphan basin were dominated by dip-slip extension. Prominent transfer faults separate different extensional tracts and accommodate different levels and polarities of detachment. The very deep Jeanne d'Arc basin formed above the deepest level of detachment. Late Callovian to Aptian extension dominated the central Grand Banks where the postrift sequence is thin. Orphan basin was formed largely by Late Cretaceous-early Tertiary extension.
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Extensional Tectonics and Stratigraphy of the North Atlantic Margins
Stimulated by the wealth of frontier exploration data and deep seismic surveys about the North Atlantic margins, this publication was crafted to provide a comprehensive analysis of North Atlantic extension. The 40 papers in this volume are divided into 6 sections: concepts, North Atlantic perspectives, North American margins, European-African margins, North Sea and Barents Shelf, and analogs. This book is concerned primarily with the circum-North Atlantic data base. It is largely biased toward presentation and interpretation of data rather than being model driven. The book includes comparative stratigraphic columns for basins of the North Atlantic margins.