HR: 14:40h
AN: T13F-05    [Abstracts]
TI: Residual topography in the north-central Mediterranean: A product of underlying mantle flow?
AU: * Shaw, M
EM: shaw@geology.utoronto.ca
AF: Department of Geology, University of Toronto, 22 Russell St., Toronto, ON M5S 3B1 Canada
AU: Pysklywec, R N
EM: russ@geology.utoronto.ca
AF: Department of Geology, University of Toronto, 22 Russell St., Toronto, ON M5S 3B1 Canada
AB: The north-central Mediterranean demonstrates an interesting history of horizontal and vertical tectonics, for which the responsible dynamical mechanisms are not well understood. Here we investigate the potential role of interpreted mantle flow in generating anomalous present-day elevation in the region. We inferred underlying mantle structure from regional seismic tomography. A tomography section cutting approximately perpendicular through the northern Apennines was translated into the temperature domain and the temperature anomalies were then superimposed into a 2D thermo-mechanical numerical model. The 2D thermo-mechanical model was then used to predict lithosphere-upper mantle deformation. Residual topography (i.e., non-isostatic topography) for the Mediterranean region was calculated from the global CRUST2.0 database and from independent estimates of crustal structure. The observed residual topography was then compared with the surface dynamic topography signal predicted by the computed mantle flow. A spatial correlation was found between the dynamic effects of underlying mantle structure and 1) the observed negative residual topography signal over the Adriatic Sea, 2) a positive residual topography signal in the Alpi Apuane region of Italy, and 3) a slight negative residual topography signal in the Liguro-Provencal basin. We also tested the response of the surface topography to various configurations of the surface plates, including variably strong lithosphere and the presence of a weak mantle wedge and weak zones in the crust. While it was found that the properties of the overlying plate heavily influence the degree of correlation, the results demonstrate that underlying mantle structure has the potential to play a significant role in supporting the observed residual topography anomalies along the investigated profile.
DE: 8104 Continental margins: convergent
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
DE: 8138 Lithospheric flexure
SC: Tectonophysics [T]
MN: Fall Meeting 2005