In September 1986, a 120-km-long seismic line was recorded through the Swiss Alps. The line traverses major units involved in thin- and thick-skinned Alpine tectonics. Our preliminary interpretation indicates that (1) lithologic boundaries such as basement-cover contacts, although severely deformed during the Alpine orogeny, can be identified on the seismic sections; (2) the top of the Aar massif, an external basement massif, extends deep into the Alpine orogen; (3) the upper and lower parts of the crust are more or less transparent, but are separated by a swarm of reflectors at mid-crustal level; (4) these mid-crustal reflectors might be related to trapped fluids from Alpine metamorphism; and (5) the Moho appears as a bright reflection that steepens from the north toward the south and terminates abruptly near the center of the Alpine chain, perhaps because of Alpine deformation.

First Page Preview

First page PDF preview
You do not currently have access to this article.