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Educational Trail Rotava

The Kernberg Basalt Quarry

The situation map

Today, the Kernberg Hill we known only from historical postcards. On its place is now flooded quarry pit. Kernberg steeply towered 76 m above the surrounding landscape. It consisted of extremely hard volcanic basalt-like rock, which broke out in columns. The igneous body narrowed cylindrical toward the deep. The volcanic conduit was at a depth of 50–100 m below the surrounding plain only 30–50 m wide. The rock columns were radial arranged, in the middle already vertical and towards the perimeter of the body gradually tilted to almost horizontal. They reached a record height of over 40 meters.

The Kernberg quarry in 1925

The scientific name of the Kernberg rock is nepheline basanite. The microscopic image contains augite, olivine, nepheline, rare feldspar and volcanic glass. The rock closes molten fragments of granite of the millimetres to meters size.

The earliest mention of the existence of the quarry producing gravel and fluxing agent for iron ore smelting works are from 1785. In 1905 built there the “Erzgebirge Basaltsplittwerke” Company steam crushing and screening plants. The company produced also basalt cobbles, which were exported to the whole monarchy and abroad. In 1920, the company “Vereinigte Basaltsteinbruchwer­ke” from in Karlovy Vary purchased the quarry. The aggregate was supplied also to the glass factory in Nové Sedlo because colourised bottle glass into the desired bright green colour. In the 1930th mined in the quarry aggregate for roads and railways the company Franz Wolf from Kraslice. During both world wars, in the quarry worked POWs and forced labour people.

Ironworks and Kernberg in 1943

After 1945, the company was nationalized. In 1946, the mine produced 37,000 tons of first-rate road and rail aggregate, next to a small amount of paving, guard stones and blocks for reinforcement of river beds and embankments. In the 1960ies involved the annual extraction of around 120,000 tons of aggregate. To 1969, the hill was almost levelled with the surrounding terrain. In 1977 took over the quarry the “Lignite Mines and Briquette Plants” from Sokolov, which annually produced 90,000 tons aggregate. In 1995, reserves are exhausted and the quarry was re closed.

The Kernberg Quarry before flooding (1997)

The Kernberg Quarry in 2012

This text was written by Petr Rojík.

GPS position

N 50° 17.998', E 12° 35.273'
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