Gravel pit
In a gravel mining the promotion of the construction materials Gravel, sand and gravel occurs. He is also known as gravel or gravel pit, at a large industrial scale as a gravel pit.
Average gravel surface mines have an extent of between about 50 and 300 meters and the degradation occurs with excavators or similar clearing equipment. The depth reduction can range from a few meters up to almost 50 m, amount of the possible excavation many 100,000 cubic meters.
In Germany, Austria and most EU countries, the approval of the degradation of bulk commodities today strict requirements of environmental protection and zoning subject.
Many operators of gravel surface mines also work as a transport company, for larger earthworks or for excavation of pits.
Deposits
Larger deposits these so-called " mass commodities " sediments are found on river terraces - such as in the Rhine valley - and as terminal moraines of glaciers of the Ice Age. Through large-scale shipment, orogeny or other tectonic gravel can take far -surface layers located deep underground - such as in northern Germany, in the area of former ice-age glaciers or in the Molasse Zone of the Alpine Foothills, such as in Upper Swabia.
Floods in levels of the valley of streams and in earlier meanders up boulders and gravel can accumulate in larger amounts or form gravel bars.
End of dismantling and re-use
Abandoned surface mines are examined for contamination and to any soil contamination. The steep slopes and escarpments must be flattened. If the incurred in promoting cavities and pits after completion of degradation remain open, fill it mostly with groundwater and there is a gravel pit. These lakes are (as well as the brick ponds ) later - and often while already - used as a fish or lake and suitability for part of a recreation area.
Also, bird and nature reserves may arise. Especially in shallow water zones, often formed by re-injection of fine sands from the treatment plants, are excellent conditions for a variety partly endangered species.
If there is little or no contact with groundwater is the hole mostly filled. This may include a landfill for excavation, construction debris or household waste. In earlier times, some pits were also provided with a special seal and used for the storage of hazardous waste, but now has its own ways of disposal. With films ( geotextiles ), however, the municipal solid waste landfills are covered today.
Some of the former gravel surface mines are used as Swingolfanlagen (eg in Handewitt in Flensburg, Schülp in Central Holstein), other than motocross course (including in Kayhof, Eastern Holstein ), for youth festivals (including " Stonehenge " in Upper Austria ) or for use exercises (eg by divers seasons ).
The proposed re-use is already fixed in the application process in the context of spatial planning in landscape conservation support plan (LBP ). While claims of nature conservation is primarily used to satisfy, since the degradation is a serious encroachment on the natural environment and the landscape. It must here to provide compensation, generally in the ratio of 1:1. This is done by renaturation of the mining area, or providing compensation area of the same size.