Tectonic inheritance at multiple scales during more than two complete Wilson cycles recorded in eastern North America
Published:November 11, 2019
William A. Thomas, 2019. "Tectonic inheritance at multiple scales during more than two complete Wilson cycles recorded in eastern North America", Fifty Years of the Wilson Cycle Concept in Plate Tectonics, R. W. Wilson, G. A. Houseman, K. J. W. McCaffrey, A. G. Doré, S. J. H. Buiter
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Eastern North America holds clear records of two Wilson cycles and hints of two earlier cycles, through which tectonic inheritance is evident at multiple scales. Large-scale transform offsets of rifted margins indicate inheritance through multiple cycles; transform-parallel intracratonic fault systems suggest a transform-parallel fabric in the lithosphere. Rift segments of the continental margins did not inherit the locations of earlier rifts; synrift intracratonic fault systems follow earlier contractional fabrics of supercontinent assembly. Large-scale curves of the Appalachian–Ouachita orogenic belt (closing of the Iapetus Ocean) mimic the shape of the Iapetan rifted margin of Laurentia. Basins along the Iapetan rifted margin reflect inheritance from transform faults in the greater magnitudes of early post-rift thermal subsidence and later synorogenic tectonic loading and flexural subsidence. Older synrift basement faults buttressed the frontal ramps of Appalachian–Ouachita thin-skinned thrust faults. Basement fault blocks and associated synrift stratigraphic variations in the weak layers that host the regional décollement localized transverse alignments of lateral ramps, as well as tectonic thickening of a mud-dominated graben-fill succession in a ductile duplex (mushwad). The many examples of tectonic inheritance attest to the linkages between processes of successive opening and closing of oceans, as well as the break-up and assembly of supercontinents, through successive Wilson cycles.
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Fifty Years of the Wilson Cycle Concept in Plate Tectonics
CONTAINS OPEN ACCESS
Fifty years ago, Tuzo Wilson published his paper asking ‘Did the Atlantic close and then re-open?’. This led to the ‘Wilson Cycle’ concept in which the repeated opening and closing of ocean basins along old orogenic belts is a key process in the assembly and breakup of supercontinents. The Wilson Cycle underlies much of what we know about the geological evolution of the Earth and its lithosphere, and will no doubt continue to be developed as we gain more understanding of the physical processes that control mantle convection, plate tectonics, and as more data become available from currently less accessible regions.
This volume includes both thematic and review papers covering various aspects of the Wilson Cycle concept. Thematic sections include: (1) the Classic Wilson v. Supercontinent Cycles, (2) Mantle Dynamics in the Wilson Cycle, (3) Tectonic Inheritance in the Lithosphere, (4) Revisiting Tuzo's question on the Atlantic, (5) Opening and Closing of Oceans, and (6) Cratonic Basins and their place in the Wilson Cycle.