Journal of

GEOsciences

  (Formerly Journal of the Czech Geological Society)

Original Paper

Dvořák

Neogene valley fill near Jedovnice and the question of age of main cave levels in the northern part of the Moravian karst

Journal of the Czech Geological Society, volume 39 (1994), issue 2-3, 235 - 240

Detailed gravimetric measurements in the southhern vicinity of Jedovnice in the Moravian Karst proved erosional nature of depressions filled with lower Badenian sediments. Following data of hydrogeologic wells and altitudinal comparison, the existence of pre-Badenian blind valley to southwest of Jedovnice and pre-Badenian cave levels between Jedovnice and Býčí skála in the Křtiny Valley were proved.
The southern part of the Drahany Upland was drained, during Paleogene period, in the north - south direction into sea embayment of subsiding Nesvačilka block southeast of Brno. The highest discharge had Svitava River draining smaller tributary basins of Punkva River, paleo-Jedovnický and Křtinský Creeks. Cave level at Sloup and Holštejn is connected with this valley system. Ramp valley of Vyškov Gate was originated in lower Karpathian and caused rapid backward erosion of streams flowing in northwest- southeast direction. Piracy of paleo-Rakovecký Creek beheaded paleo-Jedovnický creek in southeastern vicinity of Jedovnice. In that time, paleo-Jedovnický Creek was deeply entrenched in lower Carboniferous elastics (130 m) and entering pure Devonian limestones disappeared in subhorizontal cave system at the end of blind valey. Karst spring was situated in the Býčí skála Cave in Křtinské Valley. Large portion of the Drahany Upland was submerged in lower Badenian (Neogene) sea. Jedovnice blind valley was filled by marine Badenian deposits. After the regression, new valley was formed by Jedovnický creak. Waters fall down in 90 m deep chasm into cave system linked with pre-Badenian cave level.