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

Abstract

Surface 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.

Potential Impacts of Zone-Specific Mining on Karst

“…The material from the overlying beds is known to enter these fissures either by suffosion, leading to the formation of pseudokarstic suffosion dolines, or by collapse, resulting in pseudokarstic dropout dolines. Such mechanisms have been identified in the formation of subsidence dolines at Bocskor Hill in Hungary [27].…”

“…It is observed that mining operations in this region may target the extraction of karstic rock or minerals associated with karstic features. The diversity of infill within karst depressions is noted, ranging from bauxite [26] to iron ore [2], and including interbedded materials such as coal [27].…”

“…The high permeability of karst allows for rapid and widespread dissemination of these changes through karstwater. Veress [26], and Veress et al [27] have specifically addressed the impact of mining on karst in the Bakony Region.…”

Rubble Mines in the Environs of Veszprém (Bakony Region, Hungary)

“…Mines may be excavated by underground mining or surface mining. Studies on the relationship between mining and karstic landscapes have become widespread [9][10][11][12][13]. In the Bakony Region, several studies have mentioned the relationship between mining and karst and paleokarst (for example) [14].…”

The Effect of Mining Activities on the Paleokarstic Features, Recent Karstic Features, and Karst Water of the Bakony Region (Hungary)

“…During karstification karst depressions (solution dolines), poljes and inselberg karst developed [5,8,9]. Its present surface karst is of an island-like pattern and covered karst that developed on blocks of medium elevation [10]. Features of its covered karst are suffosion dolines, but solution dolines also occur in small numbers at the margin of the mountains [10].…”