Is lower crustal layering related to extension?

Abstract

The Western Approaches Margin (WAM) profile was shot to test the hypothesis that the reflectivity observed in the lower crust is related to extensional processes. The preliminary results of the experiment show that the reflectivity in the lower crust appears to become weaker on the continental shelf near the slope break. Detailed examination of the data however, show a significant increase in noise in the region where the layering appears to fade. The noise may be of sufficient amplitude to obscure any coherent lower crustal events present. Therefore, the only conclusion that can presently be drawn from the dataset is that the layering does not become more pronounced in the region of maximum extension.