Datapages, Inc.Print this page

Combined Rigid/Deformable Plate Tectonic Reconstructions for the Central Atlantic Margins

Glover, Claire T.*1; Adriasola Munoz, Alberto 1; Harris, Jim 1; Goodrich, Mike 1; Hudson, Lynne 1
(1) Fugro Robertson Limited, Llandudno, United Kingdom.

Passive continental margins are characterised by a transition zone from continental rifting to oceanic crust accretion. The exact location of the continent-ocean boundary (COB) is often difficult to predict because of the similar physical properties of oceanic crust and highly extended continental crust. Magmatic intrusions have an effect on the calculation of crustal thickness, which adds further uncertainty to the definition of the COB.

The Iberian and Newfoundland conjugate margins are zones which record anomalously large amounts of crustal extension. Within this segment of the Atlantic margins, the formation of continental ‘rafts’, comprising highly attenuated continental crust, poorly defined oceanic crust and exhumed mantle, is characteristic. The reconstruction of plate boundaries to their pre-extended configurations assuming ‘rigid’ plate geometries results in large misfits across plate boundaries (e.g. by restoring North America, Iberia, Greenland and Europe Plates, including the Hatton Bank to the Late Jurassic). In order to solve these problems and utilise the information on the amounts of continental extension along passive margins, a new combined rigid/deformable plate kinematic model has been developed, consisting of a complex global chain of rigid plates rotating around a fixed hotspot frame and deformable plates defined along continental margins and within cratonic interiors.

Modelling of the continental deformation has been achieved by creating displacement vector maps for multiple time periods. The deformation is modelled using a unique ArcGISTM extension that allows restoration of the plate margins through a process of ‘warping’. The program also allows the restoration of the geometries of geo-referenced datasets that can be intersected with the plates defined by the model. To date, a self-consistent global, plate tectonic model has been achieved, that incorporates stretching factors and scales deformation for the Cenozoic and Mesozoic for the entire Atlantic margin. Restoration to the pre-rift geometries of the margin in these areas can be refined further by detailed modelling of tectonic evolution and the extent of crustal deformation and provides insight to the pre-rift and syn-rift geometries of these margins.


AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California