ملخص: The long-wavelength magnetic anomaly field derived from Magsat data is modelled by large-scale lateral magnetization variations in the continental lithosphere of Europe, central and southeast Asia. A simple model with six domains with uniform magnetization is shown to be consistent with this long-wavelength anomaly field. In this model, all major alpine mountain belts are associated with magnetization lows and Proterozoic cratons with magnetization highs. In particular, a significant contrast of magnetization is associated with the Tornquist-Tesseyre Line, the structural boundary between the Paleozoic western part of Europe and the Proterozoic eastern domain. It is thus proposed that the magnetization contrasts and their associated long-wavelength magnetic anomalies may be attributed to differences of tectono-thermal age of the lithosphere. The main magnetization contrasts displayed by the model are then shown to be associated with seismic velocity contrasts. This observation supports the hypothesis that magnetization variations are generated by magnetic sources distributed over the whole upper lithosphere, down to the depth of the 600[deg]C isotherm. To support this conclusion, it is shown that the magnetic thickness predicted by the magnetization model obtained is in good agreement with the depth of the 600[deg]C deduced from heat flow measurements.

لغة: إنجليزية