Applicability of complex geophysical surveying in paleoseismic studies: three case studies from the Bohemian Massif
Abstrakt
We present three case studies of paleoseismic surveys in the Bohemian Massif (Czech Republic) which were carried out in various geological environments. An extensive 2-D and 3-D geophysical survey preceded and accompanied the trenching.
The trenching sites are situated on the faults reactivated in the Quaternary; in north-eastern Bohemian Massif on the Sudetic Marginal fault, at the contact of Bohemian Massif and the Carpathian Foredeep in the east (Holešov fault), and in the western Bohemian Massif on the Mariánské-Lázně fault in the Cheb basin. Combining paleoseismic trenching with geophysical surveys enabledverification and correlation of the results of geophysics with the lithology exposed in the trenches.
The methods included geoelectrical surveying, electromagnetic surveying, shallow seismics and gravimetry. They enabled to trace the faults laterally and to the depth, to map the sediments offset by the faults.Thestudies from various geological environments show that the applicability of a specific geophysical method varies depending on the site conditions.