Jan Lenart

Pseudokarst caves of the Outer Western Carpathians, Czechia

ABSTRACT The paper presents complex results of a dataset related to the pseudokarst caves in the area of the Czech Outer Western Carpathians. We collected the data from all 130 discovered and described caves of different types and dimensions in various geomorphic units and lithologies. We mainly focus on the results of the morphometric parameters of the caves as well as of the areas with their entrances. The final map sheet presents the Main Map with the position of the caves, their size category, type, classification of the position within the slope deformation and natural protection status. Moreover, the final map sheet also contains a supplementary map of the distribution of the caves, diagrams of their morphometric parameters, detailed maps of Mraznica and Cyrilka Caves, a graph of overwintering bat species in Cyrilka Cave and structural measurement diagrams. The map is intended to be used as introductory material into the problems of pseudokarst caves.

Morphological patterns of crevice-type caves in sedimentary rocks of the Outer Western Carpathians (Czech Republic)

I evaluate crevice-type caves in the Outer Western Carpathians from the morphological point of view at different scales, from the overall arrangement of cave passages within the massif, to their shape and finally to the micro-morphological features of their walls and ceilings, using examples from the Czech part of the Carpathians. The cave passages are typically parallel to and follow the strike of the slope, but the passages of relatively large caves are typically fan-like arranged. Vertically, the passages are organized at particular levels governed by lithology. They can be staircase-shifted with each other. The gradual opening of the uppermost level may lead to deformation of the surface terrain, however, this terrain can be entirely flat, which gives evidence of the gravitational widening of the caves from the inside of the massif. In cross-section, the passages are A, V, or H letter shaped, according to the type of gravitational movement leading to their development. The various micromorphological features that originate from sedimentology, tectonics, gravitational processes, and mechanical and chemical weathering sometimes mark the exposed walls and ceilings.

CREVICE-TYPE CAVES AS INDICATORS OF SLOPE FAILURES: A REVIEW PAYING A SPECIAL ATTENTION TO THE FLYSCH CARPATHIANS OF CZECHIA, POLAND, AND SLOVAKIA

The occurrence and evolution of crevice-type caves is one of the most spectacular phenomena in the progression of slope failures in distinct types of rocks. Crevices are common manifestations of disintegration of anisotropic flysch rocks in the area of the Carpathians. This paper presents the issues of the close connection between the evolution of gravitational slope deformations and the formation of crevice-type caves. Furthermore, it presents a contemporary view on the regional distribution of crevice-type caves in this area and outlines the recent progress and future possibilities of the investigation of this phenomenon. Based on the vertical distribution of different morphological zones within the caves and the main modes of their evolution, we can distinguish three basic types of crevice-type caves: (i) translational/spreading type, (ii) toppling type and (iii) rotational type.

Visualisation of volcanic relief and processes: the Nízký Jeseník upland educational trail, Czech Republic

ABSTRACT The paper presents the visualisation of volcanic relief and processes that formed the landscape of the Nízký Jeseník Upland (today recognised as a national geopark) during different phases of the Cenozoic. There are three basic types of volcanic phenomena: (i) volcanoes, (ii) lava flows and changes of relief induced by them and (iii) tuffaceous sediments. These are presented by block diagrams, panoramic maps and cross-sections on 18 panels placed along a 25 km long education trail leading through the volcanic landscape. We used a combination of GIS and graphic software to produce block diagrams based on various published and unpublished information sources. The education trail transfers scientific knowledge to the general public in an effort to contribute to the educational objectives of the Jeseníky Geopark.

The Nízký Jeseník—Highland with Abandoned Deep Mines

The Nizký Jesenik is a large flat upland area situated in the north-eastern part of the Bohemian Massif. Despite being rather uniform geologically, its geomorphic diversity is very specific as it includes structural, depositional, erosional, volcanic, periglacial and man-made landforms. The Nizký Jesenik consists chiefly of Lower Carboniferous sedimentary flysch rocks: greywackes (sandstones and conglomerates) alternating with slate or siltstones , which were folded and thrusted during the Variscan orogeny. During the successive long-term evolution the whole massif was shaped by various processes with a long-standing geomorphic impact, including protracted denudation that led to the formation of a vast planation surface. Gradual tertiary tectonic uplift caused deep incision of rivers. Neogene–Pleistocene volcanic eruptions formed conical volcanoes , lava flows and a lava-dammed lake . Pleistocene evolution under the conditions of periglacial climate shaped asymmetric valleys–dells, whereas gullies and alluvial fans were formed in the Holocene. Finally, the area has been recently affected by human impact, as testified by diverse surface and underground mining and military landforms .

Landslide Landscape of the Moravskoslezské Beskydy Mountains and Their Surroundings

Moravskoslezske Beskydy Mts represent the highest part of the Western Carpathians in the Czech Republic and could serve as an archetype of elevated flysch landscape that originated within the Alpine thrust-and-fold belt . Major landforms of the area originated as a consequence of Miocene thrusting , rock control (alternation of sandstone and shale layers of different rock strength), fluvial processes and mass movements . Of major importance are ancient and active landslides that play a crucial role in increasing geodiversity of the mountain slopes. The Moravskoslezske Beskydy Mts together with surrounding flysch highlands host the most frequent and developed crevice-type caves in the Czech Republic, which makes this area unique in Central European context. However, increasing tourism together with intensive forest management and other human activities pose a major threat to the landscape underlain by fragile flysch rocks.