Petřvald is a typical mining town in the Czech part of the Upper Silesian Basin. Since the Petřvald sub-basin is limited by significant tectonic structures, its development was to a great extent independent from other areas of the basin and can serve as an example of the influence of the geological structure on the development of mining and residential communities. In the first phase of mining development (ca 1830 to 1844) first claims begin to occur in the area. Thick coal seams were available in shallow depths. Due to missing railway connection, the demand for coal was not very large and the village economy was focused on agriculture. In the second phase (1844 to 1871), the first underground mines start to operate in the area. They were situated in favorable areas with thin overburden. Also, the connection to the railway improved the sale opportunities and a significant share of the local population worked in the mines. The third phase of mining (1871 to 1963) brought still increasing demand for coal, which resulted in establishing new coal mines in geologically less favorable areas (thicker overburden, water-bearing horizons). From the 1930s to the end of the 1950s the extraction peaked, which coincided with the urbanistic and cultural climax. New housing was provided for miners and their families by the companies. The final stage of mining development (1963 to 1998) is connected with the steady decline of production and phase-out of mining. The reason was a lack of economically recoverable coal reserves connected to unfavorable geological conditions. We conclude that the results of studies concerning specific geological parameters of coal deposits can be used for more detailed analyses regarding the development of urbanism, or to explain its causes.

This paper aims to characterize and interpret the trends in reserves, resources, and mine production of diatomite in the Czech Republic in last two decades. With more than 2.4 million tonnes of total reserves, 1.6 million tonnes of exploitable (recoverable) reserves, and average annual production of 35 kt, diatomite is not one of the key industrial minerals of the Czech Republic, which ranks among the top 10 European producers. Historical diatomite deposits were situated within the Cheb Basin, where the Holocene Hájek diatomite deposit was abandoned in 1955 because of the establishment of the Soos National Natural Monument. The group of Tertiary diatomite deposits situated in the Central Bohemian Upland ceased extraction when the last deposit (Kučlín) was abandoned in 1966 after depletion of reserves. The last group of diatomite deposits is located within the Southern Bohemian basins, where the last productive deposit, Borovany-Ledenice, is situated. Miocene diatomites are extracted by open pit mining there. Production of crude diatomite varied from 0 to 83 kt, with an average of 35 kt, between 1999 and 2018 according to stockpiles. Raw diatomite is classified into two groups according to the chemical-technological properties. Better-quality diatomite (SiO2 ≥ 72%, Al2O3 ≤ 15%, Fe2O3 < 2.4%, bulk density 450 kg/m3, loss on ignition < 8%) is processed for filtration in the food industry (brewery, wine, and raw fruit juices). Material with lower quality is used in combination with bentonite to prepare cat litter products.