Pit 7
| Pit 7 | |||
|---|---|---|---|
| General information about the mine | |||
 |
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| Mining technology | Open pit | ||
| Information about the mining company | |||
| Operating company | Rheinkalk GmbH Dornap plant | ||
| Start of operation | 1899 | ||
| End of operation | 1966 | ||
| Funded raw materials | |||
| Degradation of | limestone | ||
| Geographical location | |||
| Coordinates | 51 ° 13 '54 " N , 7 ° 1' 10" E | ||
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| Location | Greetings | ||
| local community | Haan | ||
| District ( NUTS3 ) | Mettmann | ||
| country | State of North Rhine-Westphalia | ||
| Country | Germany | ||
The pit 7 is a former limestone quarry in Haaner district Gruiten on the edge of the forest Osterholz on the outskirts of Wuppertal . Since 1997 it has been designated as a nature reserve.
history
From the quarry established in 1899 dolomitized mass limestone was extracted from the Gruiten-Dornaper mass limestone range , which was initially used as a furnace surcharge for the blast furnaces in Haan and the surrounding area . The rock was transported to Gruiten by cable car and mine railway , where it was partly transferred to a works train that ran through the Düsseltal to Erkrath-Hochdahl on the Düsseldorf – Elberfeld railway line , partly further to the lime sintering facility near Gruiten station . After a tunnel was built near Gruiten, trucks took over the transport in the last few years of operation . Around 1964, around 250 employees were producing 720,000 tons of stone annually.
After quarrying was stopped in 1966, the quarry served to maintain the groundwater level of the lime mining area. For this purpose, the groundwater taken from the Hahnenfurth pit was discharged into the Düssel via the Grenzbach . At the level of pit 7, the amount of water introduced was withdrawn again via an extraction structure and pumped in a controlled manner into pit 7, where it seeped into the groundwater. A control center in the Dornap lime works monitored the water parameters such as temperature , pH value , electrical conductivity , turbidity and UV absorption.
The Grubensee was a popular bathing water known under the name " Canyon " , despite the quarry being banned from entering. Access / driveway was i. d. Usually through an overgrown garden in the entrance area of the quarry. Due to a changed groundwater concept, the discharge was stopped towards the end of the 20th century and the Grubensee completely dried up. During this time, parts of the quarry were made accessible to the public in the form of secured hiking trails on the break edge and lookout points were set up. The Eulenkopfweg and other Haaner local hiking trails lead through the Bruch.
Soon after the quarrying operation, rare plant and animal species settled in pit 7. An inventory in 1992 showed a population of 340 plant species, seven amphibian species , 122 butterfly species , 63 bird species, seven grasshopper species and nine dragonfly species .
Nature reserve
In 1997 the quarry was designated as a nature reserve. The meadows are cared for by voluntary nature conservation organizations (AGNU Haan eV)
The protection took place:
- because of the pronounced steep walls in the fissured limestone,
- to maintain and restore the typical warmth and lime-loving quarry flora,
- to preserve the vegetation of the rocks and the rubble and scree slopes ,
- because of the dry and poor grassland ,
- for the preservation of habitats and communities of rare and endangered animal and plant species,
- because of the structural diversity,
- because of the interesting geological and pedological outcrop .
