The Habartov Quartzites

The Mystery of the Great Stone

The area around Habartov and Lítov is home to one of the richest concentrations of quartzite boulders, commonly known as “sluňáky.” The most interesting and largest stone blocks can be seen north of the village, on a walk through the suburban forest between Habartov and the Kluč district. The largest of them all has long been called “Velký kámen” (The Big Rock) and has impressive dimensions: the part protruding above ground level is 7.4 meters long, up to 5.6 meters wide, up to 3.2 meters high, and weighs about 210 tons. 

At the summit of “Velký kámen” (Big Rock) there are several rock basins formed by the weathering and erosion of the rock’s less resistant parts. The Habartov boulders date back to the deposition of the Starosedelské Formation 34 million years ago. During this period, coarse- and fine-grained gravel and sand from a prehistoric river were deposited and compacted. 

Examples of this geological process are known from the Svatava River valley near the village of the same name and, in particular, from the Ohře River valley near Staré Sedlo, after which the sequence of strata was named. Our region was located further south during this period. In the very warm climate, kaolinitic weathering of mica gneisses occurred, and the released siliceous substances cemented boulders, pebbles, and grains of sand. While soft rocks weathered over time and were washed away, the hard and resistant blocks of quartzite have survived to the present day. 

The “Velký kámen” (Big Rock) in Habartov is likely the largest sluňák in the Czech Republic. Sun-boulders are scattered throughout the Bohemian Massif; they are known, for example, from the Kadaň and Most regions, the South Bohemian basins, and the Plzeň region. As witnesses to the geological past of our region, they certainly deserve attention.

Text and photo by Petr Uhlík

Text taken from Arnika magazine