Thermal and Rheological Model of the European Lithosphere

Abstract

A thermal and rheological model of the European lithosphere (10 • W-35E; 35N-60N) is constructed based on a combination of new geophysical models. To determine temperature distribution a tomography model is used, which was improved by corrections for the crustal effect using a new digital model of the European crust (EuCRUST-07). The uppermost mantle under western Europe is generally characterized by temperatures ranging between 900 and 1,100 • C, with the hottest areas corresponding to basins, that experienced recent extension (e.g., Tyrrhenian Sea and Pannonian Basin). By contrast, upper mantle temperatures at this depth under eastern Europe are about 550-750 • C, whereby the lowest values are found in the northeastern part of the study area. EuCRUST-07 and the new thermal model are used to calculate the strength distribution within the European lithosphere. Differently from previous approaches, lateral variations of lithology and density derived from EuCRUST-07 are used to construct the new strength distribution model. Following the approach of Burov and Diament (1995), the lithospheric rheology is employed to calculate variations of the elastic thickness of the lithosphere. According to these estimates, in western Europe the lithosphere is more heterogeneous than in eastern Europe. Western Europe, with dominantly crust-mantle decoupling is mostly characterized by lower values of strength and

Global strength and elastic thickness of the lithosphere

“…decrease of the integrated strength over 25% and 50%, respectively (Tesauro et al, 2010). The values of the rheological parameters are given in Table 1.…”

“…These latter are much better constrained than absolute temperatures. The main uncertainty stems from temperature derivatives of the elastic parameters, whose uncertainties are estimated to be between 10% and 20% (Cammarano et al, 2003;Goes et al, 2000), leading to an uncertainty in the inferred temperatures of about ±70°C above 300 km (Tesauro et al, 2010).…”

“…Uncertainties in the rheological parameters, deformation mechanisms, temperatures, and assumed tectonic conditions yield uncertainties in the strength and Te estimates (e.g. Tesauro et al, 2010). Although these uncertainties affect the absolute value of the integrated strength, they have less influence on its spatial variations.…”

Global model for the lithospheric strength and effective elastic thickness

“…In contrast, the oceanic lithosphere consists of a thin crust overlying the mantle lithosphere, and consequently its strength depends primarily on the temperature distribution (e.g., Kusznir and Park, 1987). Uncertainties in the rheological parameters, deformation mechanisms, temperatures, and assumed tectonic conditions yield uncertainties in the strength (e.g., Tesauro et al, 2010). Although new laboratory measurements (e.g., Bürgmann and Dresen, 2008) have more control on the uncertainties in the rheological parameters, these experiments utilize simple monophase minerals having a homogeneous grain size, whose extension to real aggregate compositions remains to be demonstrated.…”

Perpectives on Integrated Solid Earth Sciences

“…In the companion paper by Tesauro et al (2009b) -35E; 35 N-60 N) is implemented based on a combination of recently obtained geophysical models. To determine temperature distribution they use a new tomography model, which is improved by correcting a-priori for the crustal effect using the digital model of the European crust (EuCRUST-07).…”