Extensional Tectonics Framework of the U.S. Central Atlantic Passive Margin
Published:January 01, 1989
B. Wernicke, P. G. Tilke, 1989. "Extensional Tectonics Framework of the U.S. Central Atlantic Passive Margin", Extensional Tectonics and Stratigraphy of the North Atlantic Margins, A. J. Tankard, H. R. Balkwill
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Comparison of structural and paleothermal elements of the U. S. central Atlantic passive continental margin supports previous suggestions that continental rifting tends to be asymmetrical in cross-section, periodically shifting from one sense of asymmetry to the other along strike. Our analysis indicates that inflections in the sinusoidal trace of the basement hinge zone define segments of the rifted margin with opposing asymmetry. Hinge zone embayments lie on the proximal side of rift asymmetry, whereas the salients are distal. Asymmetry is expressed by(l) the predominant tilt direction of synrift normal fault blocks and (2) synrift and postrift subsidence and uplift patterns both onshore and offshore. In contrast, the positions of the shelf-slope break, fall line, prerift orogenic front, coastline and oceanic fracture zones correlate imperfectly to poorly with rift architecture. Although the subsidence and thermal history of some offshore sedimentary basins is adequately explained by an instantaneous uniform stretching model, only asymmetrical strain accounts for the uplift and subsidence patterns for the margin as a whole, particularly if onshore subsidence patterns are considered. Although not as well understood, major aspects of the conjugate northwest African margin are compatible with the model.
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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.