Origin of cherts in the Bohemian Massif

Cherts are peculiar rocks that contain very high proportions of silica, deposited on the ocean floor from the Archean onwards. In the Bohemian Massif, cherts form characteristic rocky ridges, notably in the area of the Křivoklátsko Protected Landscape Area and in the southern part of the Brdy Mts. A new study, significantly contributed by scientists of the Institute of Geology, was published in the journal Geoscience Frontiers. It is a complex study of tens of localities with these rocks, revealing that chert formation was intimately associated with low-temperature hydrothermal activity. This was located directly on the ocean floor or on slopes of seamounts in late Proterozoic to early Cambrian times in response to a global change in silicon concentration in seawater.