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Geoffrey S. Kimbell and Philip C. Richards
The three-dimensional lithospheric structure of the Falkland Plateau region based on gravity modelling
Journal of the Geological Society of London (July 2008), 165(4):795-806

Abstract:
The lithospheric structure of the Falkland Plateau region has been modelled by making an initial estimate on the basis of local isostasy and then refining the geometries by inversion of gravity anomalies. The model predicts a crustal thickness beneath the Falkland Plateau Basin that is more than twice that previously inferred from seismic evidence. The preferred explanation is that the seismic survey detected high-velocity (?underplated) lower crust rather than upper mantle. This is compatible with the results of deep seismic experiments over the conjugate Filchner Block of Antarctica and also appears likely on the basis of the position of the Falkland Plateau Basin in relation to the Karoo-Ferrar magmatic province at the time of extension. Continental crust is inferred to be continuous beneath the northern part of the Falkland Plateau, as there are consistent magnetic and flexural anomalies associated with the continent-ocean boundary. Flexural modelling of the southern margin of the plateau indicates lateral variations in strength, with the strongest lithosphere beneath the Falkland Plateau Basin. This may indicate thick oceanic crust beneath the southern part of the basin or the effect of thinning relatively weak continental crust and replacing it with relatively strong underplating.

Index Terms/Descriptors:
Atlantic Ocean; basement; bathymetry; continental crust; crust; Falkland Plateau; Ferrar Group; flexure; free-air anomalies; geophysical methods; geophysical surveys; gravity anomalies; gravity methods; isostasy; Jurassic; Karoo Supergroup; lithosphere; magnetic anomalies; mantle plumes; Mesozoic; oceanic crust; plumes; sedimentary cover; seismic methods; South Atlantic; strength; surveys; thickness; three-dimensional models; underplating

Latitude & Longitude:
S52°30'00" - S47°30'00" and W58°00'00" - W40°00'00" (Search for maps and images at Alexandria Digital Library)

GeoRef, Copyright 2008, American Geological Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data from The Geological Society, London, London, United Kingdom