Sandstone landscape evolution

Natural long-term erosion of the sandstone areas produces various types of beautiful landforms such as: rock towers, caves, alcoves, tafoni, honeycombs, etc. . Due to specific shapes forming the sandstone landscapes, many areas built by sandstone are visited by huge number of tourists which brings economic profit for the municipal governments in these areas (e.g., Arches, Zion National Parks, USA; Pfälzerwald, Luxemoburg; the Bohemian Paradise, Elbe Sandstones and Adršpach-Teplice Cliffs, all in the Czech Republic). Sandstone areas are also often connected with ancient settlement (artificial alcoves, religious caves, sandstone cities, etc.). In addition, different sandstones have been used for building purposes during long centuries. From these reasons, researchers are interested in understanding the origin of sandstone external shapes and the processes which operate their formation and especially their weathering and decay. Salt weathering is considered to be a key factor for evolution of many sandstone landforms. However, data obtained from the long-term experimental work in Strelec Quarry in the Bohemian Paradise suggest there are some other critical governing factors..... Gaps in knowledge concerning the origin and development of the sandstone surface morphology call for a complex research and especially for a new approach. The Czech Republic is a very suitable area for study of the above outlined topics. The large variety of weathering forms in Cretaceous marine sandstones in the Bohemian Cretaceous Basin results from the different sandstone lithologies and different microclimatic conditions. 

Arsenic mineralogy and geochemistry in contaminated soils and in mine wastes

Nowadays, As is still in the focus of wide public attention mainly due to heavy poisoning of hundreds of thousands people in Bangladesh and West Bengal and in other areas around the world. Accidents with As poisoning related to drinking water provoked the legislation in many countries into tightening up the limits for As in drinking water. From 1990 to February 2007, about 17,000 papers have been published on As and its mineral species in different fields (Web of Science data). However, despite the multitude of data on As behavior in the different environmental compartments, from the lithosphere to the anthroposphere, many quantitative data published earlier are incomplete, mainly due to analytical problems and oversimplified sampling methods. Moreover, after the application of more sensitive analytical facilities and more suitable techniques, As compounds became to be determined more commonly, and As behavior was found to be more complex than formerly assumed. These facts woke a wide interest in this element. For about the last three decades, the As distribution, bonding and properties have been studied in all constituents of the geosphere. The speciation of As in, and its influence on, the living organisms are studied very attentively.
In the last two decades and mainly in recent years, many papers deal with sites contaminated by industrial and/or mining activities. On the other hand, fewer papers concern soil contamination by natural sources. As implies from the above mentioned statements, contaminated soils and different types of mine wastes are important systems on the Earth’s surface from the viewpoint of As mobility/stability. These settings are significant reservoirs providing As for the biosphere (food chains of living organisms), atmosphere (gas migration via biomethylation and wind transport of solid particles) and hydrosphere (interaction with rainfall, surface water, groundwater and soil waters). Arsenic behavior in soils and in other related materials depends mainly on the type of As bonding and on physico-chemical properties of soils (mine wastes).
The association of As with clay minerals, ferric (III) oxyhydroxides and organic matter has been well established and widely studied by many authors. However, a much lesser attention was focused on As bonding to secondary As minerals in the contaminated soils and mine wastes. The main reasons for this are probably the scarcity and substantial dispersal of the secondary As minerals in such environments, their intergrowths with other minerals and often also an unknown structure of individual secondary phases. All these facts make the investigation of secondary As minerals difficult.
Identification of As mineralogical/chemical bond is essential for all studies focused on As behavior in the uppermost part of the Earth’s crust. Complex knowledge may be achieved only by a study of both the natural and anthropogenic inputs of As into the systems. Moreover, the application of computer models of As behavior in the environment as well as the developing of remediation procedures for treatment of contaminated areas depend closely on the quality of these data. My research attempts to contribute to the current knowledge on the As mineralogical speciation in various types of solid materials, such as contaminated soils and old mine wastes. 

Karstology a speleogenesis

Salt karst was intensively studied on Mt. Sedom (Israel) in 90’s. Till lately, it is the only place with detailed study of salt karst all over the World. In the Zagros Mountains and Iranian coast of Persian Gulf, there are several tens of piercing salt diapirs with well-developed salt karst. These salt diapirs display various environments (amount of precipitation, position above the erosion base, thickness of the cap rock, development of exo- and endokarst fprms, etc.). Ten expeditions performed to the area revealed a great potential for research of salt karst which is held with greatful cooperation with reserches from the Shiraz University. Obtained results of the projects are continuously published in scientific and popular journals and in audio-visual media.. 


The main interests related tightly with mineralogy are i) topographic mineralogy of the Czech Republic and ii) cave minerals. Some contributions about this are presented in part Hobbies/Mineralogie (in Czech only) in section Příspěvky s fotodokumentací.