RECENT CRUSTAL MOVEMENTS IN THE SOUTHERN BLACK-FOREST (WESTERN GERMANY)

Precise levelling data are examined in the southern Black Forest massi f by comparing them analytically along levelling profiles. Instead of generalizing regional vertical motion trends, the method emphasizes th e current activity of accurately located individual structural element s. Measured recent crustal movement rates range from 0.2 to 1.1 mm/yea r for the 1930-1961 (1972) period, the inferred motions corresponding to aseismic fault creep. Based on the near infrared band image of a La ndsat MSS scene, a lineament map of the study area is compared with th e recent crustal movement (RCM) map. The Upper Rhine graben eastern bo rder fault between Badenweiler and Freiburg displays the highest RCM: these displacements are consistent with the geological motion and the topographic expression of that structure. Within the massif, both the lineament map and the RCM map demonstrate the predominant role played by WNW/ESE- to NW/SE-striking structures in accommodating the deformat ion. Moreover, with the seismic dislocations in the southern Black For est taking place also mainly on N120 and N20 faults, it is most probab le that these active structures are deep-reaching zones of crustal wea kness. To some extent, seismicity and RCM appear, however, to be mutua lly exclusive in their spatial distribution, the seismic Black Forest flexure and Dinkelberg block being opposed to the aseismically moving eastern and northern parts of the study area.