Open AccessDeep seismic reflectivity patterns in specific tectonic units of Western and Central Europe
Author(s) -
Sadowiak Petra,
Wever Thomas,
Meissner Rolf
Publication year - 1991
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.1991.tb03443.x
Subject(s) - geology , crust , massif , seismology , tectonics , rift , precambrian , reflection (computer programming) , upper crust , reflectivity , continental crust , extensional definition , lithosphere , paleontology , programming language , physics , computer science , optics
SUMMARY A systematic comparative study of the reflectivity of the continental crust is undertaken—made possible by the expanded data basis of deep seismic reflection profiles in Europe. The reflectivity is not at all the same but can change dramatically from one seismic line to the next. Different seismic reflectivity patterns—independent of applied techniques—are observed. Correlations between these seismic patterns and specific tectonic units can be found. While lamellae and bands of reflections in the lower crust are widespread in post‐orogenic extensional areas, ‘crocodiles’ seem to represent compressional zones that are occasionally accompanied by seismic duplex structures. The ‘fishbone’ pattern—many ‘minicrocodiles’—is characteristic for the old London‐Brabant Massif. The ‘ramp and flat’ structure displays the thin‐skinned tectonics of the North Variscan Deformation Front over a length of 2000 km. Diffraction clusters in the lower crust accompanied by a dipping reflection in the upper crust can be observed close to thick‐skinned deformation fronts. Diffractions are also present in rift areas, for example in the North Sea. Some regions show a decreasing reflectivity with depth. The reflections are concentrated in the upper crust and no Moho reflections can be observed. These areas can be correlated to areas with Precambrian crust.