From tectonic reconstruction to upper mantle model: An application to the Alpine-Mediterranean region

Abstract

De Jonge, M.R., Wortel, M.J.R. and Spakman, W., 1993. From tectonic reconstruction to upper mantle model: An application to the Alpine-Mediterranean region. In: M.J.R. Wortel, U. Hansen and R. Sabadini (Editors), Relationships between Mantle Processes and Geological Processes at or near the Earth's Surface. Tectonophysics, 223: 53–65. The seismic velocity structure of the upper mantle and lithosphere in the Mediterranean region is very complex: many areas with anomalous P-wave velocities can be recognized by means of seismic tomography. In view of the Complicated tectonic evolution of the peri-Mediterranean orogens and basins this is not surprising. In this study we will show results of a modelling approach we have recently developed to predict this structure. In this approach we make a quantitative connection between the tectonic evolution on one hand and the present seismic velocity structure on the other. Our model predicts the evolution of temperature distributions in the lower lithosphere and upper mantle, by simulating the flow of material inferred from a kinematic description of lithosphere-scale processes. From the modelled present thermal state (the endpoint of an evolution) we calculate expected seismic velocity anomalies that can be compared with results obtained by seismic tomography. Thus, the method enables us to compare the implications of geological reconstructions, describing the past tectonic processes, with seismological results for the present structure. The predicted mantle models show a good correlation with the tomographic results obtained for the mantle. This means we can verify many features present in the tectonic scenarios with the seismologically determined deep structure.