Skip to main content

Index Geophysics

Crustal structure of the Rhenish Massif and adjacent areas; a reinterpretation of existing seismic-refraction data


Title (Dublin Core)

en-US Crustal structure of the Rhenish Massif and adjacent areas; a reinterpretation of existing seismic-refraction data

Description (Dublin Core)

en-US Most of the existing seismic-refraction profiles in the Rhenish Massif/Rhenohercynian zone of Western Germany have been jointly reinterpreted using traveltime and amplitude information. The general pattern of observed phases can be divided into three types; each type corresponds to a distinct kind of velocity structure. Type I: Throughout the central Rhenish Massif and the adjacent Hessische Senke a strong P-phase reflection from the crust-mantle boundary is recorded in regions where no major volcanic features are crossed by the lines of seismic observations. The average crustal thickness is 28-29 km, the average crustal velocity (excepting sediments) is 6.2-6.3 km/sec, and the crust is nearly homogeneous. This structure is here referred to as the Rhenohercynian crustal model. Type II: Beneath the southern part of the Rhenish Massif and two areas in the northeast and southeast some structure within the crust is evident. Both an intracrustal and the Moho discontinuities are evidenced by strong reflected phases, the Moho reflection being the stronger one. Along the profiles crossing major volcanic features such as Vogelsberg and central Westerwald, but not beneath the eastern Eifel, the M-discontinuity is heavily disrupted or "smeared" and an intermediate intracrustal boundary at about 20 km depth forms the main reflector for seismic waves. Beneath this boundary the velocity increases gradually from about 7 km/sec to upper-mantle velocities. Type III: For profiles crossing the northern Rhine Graben area as well as for a line from the Siebengebirge through the Rhenish Massif to the north, east of the Lower Rhine basin, the observed phases indicate only one major seismic boundary at a depth of about 23 km where the velocity increases rapidly to 7.3 km/sec. Below this boundary the velocity increases gradually with depth reaching 8 km/sec at 27-28 km. The occurrence of types I, II, and III can be roughly correlated with tectonic setting. The Pn phase is recorded with variable success and disappears completely on a profile passing the eastern Eifel volcanics, but is clear on the lines through Vogelsberg and central Westerwald. The petrographic differences between these volcanics appear such to be reflected in the behaviour of the seismic waves. Cross sections and areal views are used to display the variations in crustal and upper mantle velocity structure.

Creator (Dublin Core)

Mooney, W.D.
Prodehl, C.

Subject (Dublin Core)

en-US Seismic-refraction profiles
en-US Crustal structure
en-US Lateral variations
en-US Rhenish Massif
en-US Rhenohercynian zone
en-US Solid Earth

Publisher (Dublin Core)

en-US Journal of Geophysics

Date (Dublin Core)


Type (Dublin Core)

en-US Peer-reviewed Article

Format (Dublin Core)


Identifier (Dublin Core)

Source (Dublin Core)

en-US Journal of Geophysics; Vol 44 No 1 (1977): Journal of Geophysics; 573-601

Language (Dublin Core)


Relation (Dublin Core)