Anna Sommaruga, Urs Eichenberger & François Marillier

SEISMIC ATLAS OF THE SWISS MOLASSE BASIN

This Atlas provides new insights into the deep structure of the Swiss Molasse Basin at regional scale, based on a three-dimensional model, from the surface down to the base of the deepest sedimentary layers at depths of updown to 7 kilometres. The work is based on synthesis of more than 4300 km of deep reflection seismic profiles and well data, most of which were collected by industry for the purpose of hydrocarbon exploration between 1960 and 1990. The data set was assembled by soliciting the archives of different companies and institutions in Switzerland. The interpretation of the seismic profiles, calibrated by more than 30 wells, made it possible to map eight seismic horizons that are near major geological boundaries within the basin.

The results are presented in 15 large sections across the entire Swiss Molasse Basin, 13 of them in the basin dip- and 2 in the basin strike directions, respectively in the NW-SE and SW-NE directions. In addition, a series of maps were constructed that provide regional information on the seismic horizons in two-way travel time and in depth.