Anthropogenic Pseudokarstic Depressions on Mount Bocskor (Bakony Region, Hungary)

Abstract

AbstractSurface forms above the mine (Ármin mine) of Mount Bocskor (Southern Bakony, Hungary) were examined. We made contour maps, plan maps, morphological maps and atectonic grike (cave) maps of some of the forms and their surroundings. We examined the distribution of the depth, length, elongation ratio in case of some depressions, the relation between the depth and the diameter of some depressions, the relationship between depression group directions and mine cut directions, the standard deviation of the direction differences of depression groups and of their depressions. The forms of the mountain related to surface mining can be separated to open and closed. The former are trenches and stairs, the latter are circular, elongated, and complex depressions. The formation of these forms can be related to the balancing movements of the vault over the mountain’s mine. At thin vault, stairs develop by collapses, while at the atectonic fissures of thicker vault, trenches and depressions are formed at the surface. In areas bordered by sinking (subsidence through) and downwardly cohesive faults, depression groups of diverse features are arranged in the marginal bands. Elongated depressions are formed at atectonic blocks bounded by dispersing faults in non-banded distribution. Where there is a superficial deposit, atectonic fissures can also be inherited directly by collapse to the surface and form depressions. They can also form indirectly over atectonic fissures by compaction, subsequent collapse and/or suffosion of the superficial deposit. The results of the study make it possible to analyse the material loss due to mining on the vault if the atectonic structures of the vault are partly or completely covered by superficial deposit.