Neanderthal limestone quarries, Mettmann, Mettmann, Düsseldorf, North Rhine-Westphalia, Germanyi

Regional Level Types
Neanderthal limestone quarries	Quarry (Flooded)
Mettmann	Town
Mettmann	District
Düsseldorf	Administrative District
North Rhine-Westphalia	State
Germany	Country

Devonian limestone with mineralized clefts. Located about 3 km SW of Mettmann.

Lime is said to have been fired in the Neander Valley area as early as the Middle Ages. In 1916, “Mannesmann AG” began to build its own quarry with an associated lime works in the Neandertal. Under changing operators, it reached its final size in 1985 with an area of ​​around 500 x 800 m and a mining depth of 120 m. The operating licence expires in 2020. Today the quarry basin is flooded, and the heaps are largely forested.

History 1916-1988

The quarry is located north of the Neandertal on the adjoining plateau. The mining follows the geological formation of the Neandertal, which was intensively exploited in the so-called “Gesteins” from the middle of the 19th century. The quarries there became famous because of the Neanderthal bones found.

Compared to the quarries in the “Gesteins” of the Neander Valley, the quarry was opened relatively late. The following historical information was kindly provided by Mr. Bank, operations manager of the Neandertal plant of CoMin GmbH & Co KG: It was not until 1916 that the Mannesmann-Blastofen-Thomaswerke from Duisburg bought the Kastein estate and in 1928 the Gathen estate on the Laubach, a small side valley of the Neandertal. There is said to have been an older quarry and lime kiln at the valley entrance below the Kastein farm. (See panoramic map of the “Gesteins” (Neandertal) by Wolfgang Wasser, 2012). The construction of the quarry is probably related to the efforts of the blast furnace works to free themselves from the monopolistic structures of the RKW Dornap. The thick layer of clay overlying the limestone, which has to be removed before quarrying, is also used economically and elegantly processed into bricks and clinker bricks in a ring kiln from 1924 onwards.

In 1925, the first lime shaft kiln in the quarry, which now belonged to “Mannesmann AG”, went into operation, followed in 1928 by three more lime shaft kilns. A jaw crusher brings the raw material to the grain size required for firing. In the 1930s and 1940s, the company had 130 workers. After the war-related decline, operations quickly resumed and in 1957 a tar macadam plant went into operation to supply material for road surfaces.
In 1964 the entire plant was modernized and new, efficient crushing and processing plants were built. These consist of one preliminary and two secondary crushers. Classification is carried out using four screening machines. Firing takes place using two modern rotary kilns that are 121.5 meters long. This includes a lime silo building for fine and lump lime with a capacity of 5,500 tons. During the 1970s, the shaft furnaces and silo systems at the old factory location were demolished.
Two more ring shaft furnaces went into operation in 1981.

Development 1988-1999

After the sale to “Rheinische Kalksteinwerke GmbH Wülfrath” in 1988, the distillation systems were demolished in 1989. Since 1993, a recycling company has been using the disused storage areas to recover raw materials. An asphalt mixing plant from “R & K Asphalt GmbH” was built at the macadam plant site in 1996.

Development from 1999-2020

After RKW Wülfrath was taken over by the “Lhoist Group” in 1999, the company was sold in 2003.
It operates as “Kalksteinwerk Neandertal GmbH” until 2015 and then becomes part of “CoMin-GmbH & Co KG”.
In the current Neandertal factory, unfired products are made from limestone. These include limestone, limestone gravel and lime mixtures for road construction and the asphalt industry. In addition, stones are obtained for gardening and landscaping as well as pond systems.
The operating licence, which originally ran until 2015, finally expired in 2020 after a five-year extension. The reason for the extension was a landslide in 2014, which caused a road to slide and led to the fault being temporarily closed.

Operators

1916: Mannesmann-Hochofen-Thomaswerk in Duisburg-Huckingen, later renamed “Mannesmann AG”
1988: Sale to “RKW Wülfrath”
1999: Takeover by the “Lhoist Group”
2000: Renamed to “Rheinkalk Neandertal GmbH”
2003: Sale to Sticker-Verbund and renaming to “Kalksteinwerk Neandertal GmbH”
2015: Change of name to “CoMin GmbH & Co KG”, Mettmann

Subsequent uses

Partial areas are used by a recycling plant and a shipping company. A long-term usage concept is still being discussed.
The continued use of the area has been discussed by politicians, the public, and the owner of the quarry for several years. The ideas are sometimes very controversial and range from amusement parks to living and recreation to strict nature conservation. As early as 2010, a master plan for the future and development of the quarry area and its connection to the neighbouring Neandertal was drawn up on behalf of the city and district of Mettmann as well as the city of Erkrath (Mettmann district, 2010). No decisions have been made yet (as of August 2021).

Expansion

When the quarry was built in 1916, the Laubachtal was used, a small side valley of the Neandertal, which cuts into the plateau north of the Neandertal. In order to make room for the lime works and the brickworks, the eastern flank of the valley was demolished over a length of 300 meters and a width of approx. 80 meters at the valley entrance, north of the Kastein estate. The facilities being built there, and the brickworks can be directly connected to the Düsseldorf-Wuppertal railway line, which runs parallel to the Neandertal, without having to overcome major differences in height. The facilities are gradually expanded and the Kastein estate is demolished.

The elongated limestone quarry on the eastern slope of the valley initially grows slowly. Only from the 1950s onwards do the maps show a rapid increase in the mining areas. In 1937 the size was only 300 x 50 meters, by 1954 the quarry had reached an extent of 380 x 180 meters. In 1975 the aerial photos show an expansion to an area of ​​up to 730 x 430 meters. After the new lime works was built in 1964, at a location about 300 meters further west, the old operating facilities were demolished around 1980 in order to be able to use the lime reserves underneath. This causes the fracture to widen by around 300 meters on its southern half. The previously preserved valley section of the Laubacher Bach with the old mill pond are removed. By 1985, the mining area reached its final size, with an area of ​​around 500 x 800 meters. The extraction now goes into depth. With over six levels, each 20 meters high, the quarry reaches a depth of 120 meters: a record in the Niederbergisches Land. It reaches almost to sea level (14 meters above sea level) and thus well below the valley level of the neighbouring Neandertal, which is 76 meters above sea level. The overburden is deposited on an elongated heap west of the quarry, not far from Gut Gathen. The Gathen estate, which was acquired in 1928, was also the headquarters of the management until a few years ago.

Transport within the quarry was switched from field railways to trackless operation in the 1950s. Heavy-duty trucks now take over the journey from the quarry to the processing plants. The so-called “dumpers” today have a capacity of 40 tons. The output in the 1990s was around 1 million tons per year.

On the ridge west of the limestone works there is a larger occurrence of fine-grained, Upper Oligocene marine sands from the Tertiary. These had greater economic importance as moulding sands in iron foundries. Even before the limestone quarry was built, it was connected directly to the Wuppertal-Düsseldorf railway line below by a 380-meter-long cable car route. The cable car route is pivoted to the north as the mining continues [Note: The sandpit and cable car are shown in the Mettmann geological map with corrections from 1919 (ed. 1930). The quarries, however, not yet]. The topographical map from 1930 shows that the moulding sandpit is now connected to the Neandertal train station with a track system that is around 1 kilometre long. It crosses the access area of ​​the lime works and is also connected to it with a branch. The route still seems to exist in 1954. From around 1960, the old sandpits were used by the lime works as a sludge pond to clarify the waste water from lime washing and were thus integrated into the operational process.

Current condition

Lime kilns and silos have not been preserved, quarry tanks are largely flooded, peripheral areas are subject to spontaneous vegetation, especially with birch trees. The slag heap is reforested with deciduous forest.

Access: Company premises, access only with the consent of “CoMin GmbH & Co KG”

Source: Information from Mr. Bank, operations manager of the Neandertal plant of CoMin GmbH & Co KG.

Other Databases

Wikipedia:	https://en.wikipedia.org/wiki/Neandertal_(valley)
Wikidata ID:	Q170081

Other Regions, Features and Areas containing this locality

References