INVESTIGADORES
DAVILA Federico Miguel
congresos y reuniones científicas
Título:
How mantle dynamics affected the topography across the southernmost Atlantics and Patagonia?
Autor/es:
DAVILA, F.M. Y LITHGOW-BERTELLONI
Reunión:
Congreso; VII Congreso Uruguayo de Geología y I Simposio de Minería y Desarrollo del Cono Sur; 2013
Resumen:
The ocean floor bathymetry across the abyssal Argentine Basin is not isostatically and thermally supported, and is displaced ~1 km deeper with respect to the half-cooling subsidence global trend. Immediately to the west, in the Patagonia plateau and the Atlantic coasts, the topography shows exactly the opposite, long-wavelength elevations that cannot be explained by simple supracrustal deformation. While the anomalous abyssal basin was associated with mantle downwellings, the plateau was associated with upwellings and the broadening of a slab window. We bring to bear a variety of geomorphic/stratigraphic and tectonic analysis that show that both topographic anomalies formed contemporaneously in the Late Miocene. We compute models of dynamic topography to explain the topographic anomalies using a spherical domain instantaneous flow model and the most recent temporal and spatial slab reconstruction of the Antarctic and Nazca plates since the early Miocene in three stages at 19, 12 and 0 Ma. These stages represent the Chile ridge migration and asthenospheric window evolution in Patagonia. While our results explain most of the Patagonian elevations, they do not reproduce the deep Argentine abyssal basin, which we attribute to other causes.