Geophysical characteristics of epikarst: case studies from Zagros Mts. (Iran) and the Koneprusy region (Czech Republic)
Pavel Bosák, Vojtech Beneš - (32/2,2003)
Characteristics of epikarst zone were studied by geophysical methods, especially refraction seismics, combined with electrical resistivity and gravimetry measurements. Applied methods were equal in both regions, so comparable results were obtained. The interpreted seismic boundaries follow the basal plane of epikarst (s.l.) and limit the epikarst zone from the geophysical point of view, i.e. zone with comparably low seismic velocities (mostly 1,000 to 3,000 m.s-1). The thickness of epikarst in the Czech Karst - the Koneprusy Devonian - is from 5 to about 60 m. The epikarst in Zagros Mts. reached up to 180 m (Cretaceous lmst.). The differences of character and vertical extent of epikarst zone depend on entirely different geological structure and geomorphological setting (relief) and evolution of both sites, which established different conditions for the release of residual stress in the limestone massifs.