Mayener pit field

Mayener pit field
General information about the mine
View into an overgrown quarry with two cranes and cut bell halls
other names	Mayener Lay / Ley (en)
Mining technology	Quarry ( open pit ) shafts
Information about the mining company
Operating company	most recently Krämer and Adorf
Employees	maximum up to 1000 (around 1910)
Start of operation	Neolithic
End of operation	1970s
Successor use	Cold rooms for breweries today tourism and natural biotope
Funded raw materials
Degradation of	Basalt ( Mayen basalt lava )
Mightiness	approx. 10-20 m
Greatest depth	approx. 30 m
Geographical location
Coordinates	50 ° 20 '4.3 "  N , 7 ° 14' 27.3"  E Coordinates: 50 ° 20 '4.3 "  N , 7 ° 14' 27.3"  E
Location Mayener pit field
local community	Mayen
District ( NUTS3 )	Mayen-Koblenz district
country	State of Rhineland-Palatinate
Country	Germany
District	Vulkaneifel

The Mayener Grubenfeld , more rarely also called Mayener Lay / Ley (en) , is a former mining area for basalt rock ( Mayener basalt lava ) on the northeastern edge of the city of Mayen in the eastern Vulkaneifel (Vordereifel) in Rhineland-Palatinate .

For more than 7000 years, from the Neolithic to the modern age , the hard and porous stone has been extracted here primarily for the production of grinding stones and mill stones, but also as stone and building material . For this purpose, several open quarries and numerous shafts and underground tunnels [sic!] Were excavated in the mine field .

After the underground mining had ended, local breweries used the tunnels that were created as rock cellars for the storage of beer .

Since the surface quarries ceased operations in the 1970s due to inefficiency, nature has reclaimed the site - it is now overgrown with vegetation and several lakes have formed. The minefield offers a habitat for numerous, sometimes threatened, plant and animal species. The area with its numerous large and small caves is particularly important as a wintering and swarming area for bats .

The pit field is part of the volcano park in the Laacher See National Geopark and the German Volcano Road . Interested visitors are shown the natural features and the history of the place in an information center (" Erlebniswelten Grubenfeld ") . A sculpture park ("Lapidea") , made from the rock extracted on site, complements the exhibition.

Geology / formation of basalt

The basalt deposits near Mayen were formed around 140,000 to 200,000 years ago, in the Quaternary , through eruptions of the Bellerberg volcanic group . At that time, viscous magma poured in at least three large-scale lava flows from the volcano into the valley of the Nette . The Mayen lava flow was about 2.5 kilometers long and 1.2 kilometers wide on average. With cooling, the lava solidified into basalt rock and overlaid as a blanket underlying layers of older, Devonian clay - and shale . The basalt layer is about 10 to a maximum of 30 meters thick. Since the lava did not completely degas before solidification, the rock is very porous (up to 25 percent bubble volume).

In the course of the following millennia, the basalt was covered by further volcanic eruptions in the region by a top layer of up to 10 meters thick from Dielstein Mountains ( breccia-like , volcanic loose rock , consisting of coarse trass ( tuff ) with embedded pieces of pumice stone , slag and other stones) .

History of basalt mining

Mining has been ongoing in the Mayen mine field for more than 7000 years. The field is therefore the oldest and most important quarry area north of the Alps.

Early days

Early rubbing stone made from Mayen basalt - demonstration of the functionality in the information center Erlebniswelten Grubenfeld (see below)

Since the top layer in Mayen's pit box - unlike Mendig - in some places over time by erosion was as far removed that the basalt came clearly to light, the occurrence in Mayen in prehistoric times were known. After it was noticed that the Mayen basalt was ideally suited for grinding grain due to its hardness and porosity , regular use of the rock developed in the early days , especially for the production of rubstones . The earliest finds of rubstones made from Mayen basalt are dated to the Neolithic Age ( early Neolithic , approx. 5000 BC). Initially only the stone blocks lying on the surface were collected and used. Larger blocks were crushed by setting fire and using wedges and levers. From the Urnfield Period (around 1000 BC) the first, shallow quarry pits were found, which were driven into the basalt.

At the latest from the time of the Michelsberg culture (approx. 3000 BC) stone tools such as impact balls, stone axes and hammers (so-called grooved mallets ) were made from Mayen hard basalt. On the one hand, these were used on site for the extraction and processing of the basalt rub stones, but on the other hand they were also used as tools for other purposes.

In the Iron Age ( Hallstatt and Latène times , from approx. 800 BC) Mayen basalt was still used for the production of advanced rubbing stones, so-called " Napoleon hats ", and finally for the first simple millstones for hand turning mills (cross stones). As finds in other parts of Europe show, the stones from Mayen were already traded over long distances by the Celts.

Antiquity (Roman antiquity)

After the Romans had extended their empire to the Rhine in the Gallic War against the Germanic peoples (from 55 BC), the Mayen mine field belonged to the Roman province of Germania superior . Very soon the Romans also became aware of the excellent suitability of Mayen basalt as a millstone and began systematic mining. At peak times, around 600 workers were already working in the Roman Mayen millstone quarries, about as many as in modern times.

The Romans made millstones of various types and sizes from Mayen basalt, from "legionnaires' mills", small hand mills that the Roman army took with them on their war campaigns for daily food, to large Göpel mills with the hourglass shape typical of Romans, which were made by several people or animals had to be rotated.

The stone and millstone blanks obtained in the Mayen quarry were shipped from the Roman Rhine port in Andernach to all parts of the Roman Empire. The Mayen stones reached the Neckar, the Upper Rhine and the Danube, but also to distant provinces of the Roman Empire, such as Britain and even the Mediterranean . For example, Mayen millstones have been found in the ruins of the Roman settlement of Volubilis in northern Morocco. The stones were also traded with other peoples, such as finds in the Viking trading town of Haitabu show. The origin of the stones from Mayen could be proven by petrological investigations.

middle Ages

In order to be able to extract the deeper rock without having to remove the 10-meter-thick overburden , from the late Middle Ages (from approx. 1400 AD), more and more people started mining underground . For this purpose, a lined shaft with a diameter of about 7–8 meters was sunk ( sunk ) through the overburden to get to the basalt. In the basalt the shaft was widened to a cave. The roof of this cave was formed by the upper, now hanging ends ("bells") of the dismantled basalt columns ("rails"). To force out of bells from the ridges (cave ceiling) or even a broken go (collapse) all over the cave to prevent the bells were hammering of wooden wedges in the intervening chasms , braced (columns) so far that the bells a stable, self-supporting, natural vault formed, which is called "Geglöck (s)". Basalt columns were also left standing as pillars at regular intervals to stabilize larger bell halls.

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  Shaft opening on the surface (Ø approx. 8 m)

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  Shaft opening on the surface (Ø approx. 5 m)

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  View into a shaft: At the bottom you can see the cave, the "goblet (s)".

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  Ridges made of basalt "bells"

From the bell hall under a shaft, further corridors (colloquially often incorrectly referred to as " tunnels ") and halls were driven into the rock. The numerous shafts and halls were thus connected to an underground network.

The stones recovered were brought underground to the shaft and muscle power - first with reels , from about 1700 with the help of large, powered by humans or horses Göpel works drawn through the shaft to the top -. The layers, too, climbed in and out of ladders (in mining: journeys ) through such shafts, hence also called journeys trum .

Modern times

In the second half of the 19th century, the small wind and water mills that had been widespread until then were increasingly replaced by larger, modern mills that could produce the flour cheaply and in large quantities. Since the new mills worked with roller mills instead of grinding cycles , i.e. no millstones, and since the remaining traditional mills increasingly used imported stones (e.g. from French freshwater quartzite), the demand for Mayen basalt millstones rose rapidly until the end of the 19th century back. As a result of the slump in sales, the underground mining of millstone blanks in Mayen was cut back sharply from around 1870 and finally abandoned around 1900 due to inefficiency. The resulting underground halls were then only used as rock cellars to cool beer (see below).

After the end of millstone production, Mayener basalt was only used as stone and as a building material for railway and road construction, as paving stone , gravel, etc. used. From around 1870 onwards, mining was again mainly carried out using the opencast mining method in open quarries. The basalt recovered was after treatment with Loren brought to Mayener Ostbahnhof. In 1878 a railway line was opened from Andernach via Mendig to Mayen , which was mainly used to transport basalt.

Until around 1900 the stones were broken out of the mountain by the workers with simple hand tools and worked on. At the height of this labor-intensive way of working, before the First World War, up to 1,000 workers were employed in the Mayen mine field. The first electric cranes and pneumatic hammers were used from the beginning of the 20th century . In the mid-1920s, electric saws were introduced for making large blocks of stone. For the production of ballast, modern gravel works with mechanical crushers and sorting were increasingly being built .

Large-scale basalt mining in the former historic mine field continued until the 1970s, when the economically viable reserves were exhausted and operations were either stopped or relocated. Even today (as of 2014), basalt is commercially mined as a building material in open-cast mining in the edge area of ​​the Mayen lava flow on the north and east sides of the historic mine field.

Successor use as a beer cellar

Thanks to the constant, cool temperatures of around 8 ° C, the underground caves, which were created by the basalt mining, are ideal as rock cellars for storing perishable food. Before the development of artificial cooling, such natural cooling rooms were very popular. In Mayen, the caves of the mine field, similar to the lava cellars in neighboring Mendig, were primarily used by breweries as beer cellars for the production and storage of beer . The numerous rock cellars represented such a locational advantage that from 1840 onwards numerous breweries settled in Mayen and Mendig. Only after the invention of the refrigeration machine by Carl von Linde (1876) did the beer cellars in the Mayener mine field slowly lose their importance. However, some were still in use until the middle of the 20th century.

Today's condition and presentation

Traces of mining

Of the former 1.5 square kilometer mine field, only about 100 hectares are now preserved in their historical state. The site is protected as a cultural monument and entered on the list of cultural monuments in Mayen .

In large areas of the former mining field, in which the basalt was mainly extracted underground, the former shafts were filled, the open-pit facilities demolished, the surface leveled, and an industrial area was established. A part has been reforested or is used for agriculture. Quarries are still operated in some peripheral areas.

Underground shafts and peaks

The daytime opening of shaft 700 with a stair tower built in later

The majority of the formerly up to 500 shafts were discarded (abandoned) after the recoverable basalt had been extracted. Some were simply left to their own devices until they eventually broke, in whole or in part . Others were filled with overburden and basalt rubble from the neighboring shafts - sometimes only in modern times, in order to keep the shaft safe and secure the area above it and make it usable for development. Still other shafts, which were located near the open quarries, were cut at some point during the expansion of the quarry pits and finally completely or partially dismantled. Today only fewer than a dozen shafts are visible on the surface (see pictures above).

Most of the underground peaks and tunnels have now also been filled in or broken. Some have been preserved, but not accessible to people due to the risk of collapse. Some of the few larger halls that are accessible, in particular the MAYKO beer cellar , the wall tunnel and another tunnel, were stabilized between 2009 and 2011 in a collaboration between authorities and NABU in order to save them from collapsing and to keep them as bat quarters (see below).

In 2013 , a stair tower was installed in shaft 700 , a well-preserved shaft not far from the information center Erlebniswelten Grubenfeld (see below), in order to enable visitors to descend safely and look into a corner (see picture).

Quarry residual holes and processing plants

In the preserved part of the field you can see several remaining quarry holes , which are now heavily overgrown with plants. In some pits, groundwater and rainwater have collected so that water holes have formed; the largest of these is the silver lake . Most of the large quarries date from modern times, but there are also smaller remains of mining sites from Roman and prehistoric times.

On the steep edges of the quarry pits, some modern cranes and the pedestals provided for them have been preserved. In places there are also the tracks over which the trolleys and lorries with the stone were transported from the quarry to the processing . From the processing, consisting of a crushing mill , sawmill , warehouse, etc., there are still a sedimentation basin and some buildings, some as ruins.

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  Quarry with two old cranes

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  Old crane on the edge of the quarry

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  Another crane

Natural biotope and protected area

Subterranean disused basalt mines Mayen and Niedermendig Mayener pit field IUCN Category IV - Habitat / Species Management Area
location	Mayen , Mayen-Koblenz district , Rhineland-Palatinate , Germany
Identifier	NSG : 7137-05x?
WDPA ID	555520946
Natura 2000 ID	[28] DE-5609-301
FFH area	152 ha
Geographical location	50 ° 20 '  N , 7 ° 14'  E
Setup date	FFH: 2000 NSG: 2014
administration	FFH: State Office for Environment, Water Management and Trade Inspectorate Rhineland-Palatinate

It was not until the 1990s that the importance of the Mayen mine field as an outstanding bat roost was recognized, and efforts were made to protect the area accordingly. Parts of the Mayen mine field have belonged to the FFH area "Underground, disused basalt mines Mayen and Niedermendig" (DE-5609-301) since 2000 .

In 2007, a large-scale nature conservation project was set up in the Mayener pit field in cooperation with authorities and nature conservation associations (especially NABU ) . Previously, NABU Rhineland-Palatinate, with financial support from the Federal Agency for Nature Conservation and the State of Rhineland-Palatinate, purchased the core area of ​​the mine field with the three largest tunnels in order to ensure their preservation.

After the Upper conservation authority in the Structural and Approval Directorate (SGD) North had planned in Koblenz for some time already to provide a portion of the mining area a nature reserve, which was posted on May 2, 2014 Nature Reserve , in the presence of Rhineland-Palatinate Environment Minister Ulrike Höfken the public presented and officially "inaugurated". A challenge in the establishment of the nature reserve was the multiple special significance of the area as a unique natural biotope on the one hand and as a cultural monument, archaeological site and tourist attraction on the other.

Furthermore, two basalt rocks, protected as natural monuments , were erected in the area, which formerly come from the district of Vorn in der Ahl north of Mayen.

Bat roost

The frost and damp caves of Mayener mining area are at least 14 species of bats hibernate and two other as a swarm quarters, which are: Mops , North , Bechstein , pond , water , Natterer , mosquito , Rauhaut- and pipistrelle , Large and whiskered bat , greater mouse-eared , greater horseshoe bat , Brown and Gray long-eared . Also broad- and Schreiber's bat , were spotted in the mine field, but only hunting or as a skeleton. Furthermore, it is considered likely that the Little Horseshoe Bat , which is no longer to be found in the region, lived in the Mayener Layen until around 1960 . Many of these species are on the Red List of Endangered Species .

According to censuses and estimates by the Rhineland-Palatinate Bat Conservation Working Group and NABU, up to 50,000 bats use the Mayen caves as quarters. Since the count is very difficult and the "real figure" is very high, the number could be up to 100,000. During the swarming season, in late summer and autumn, the animals come together from a radius of up to 300 km. Together with the nearby cave system at Niedermendig , which was also created from underground basalt mining, the Mayener Grubenfeld is probably the most important wintering area for bats in Germany and, according to EUROBATS, one of the most important bat roosts in Central Europe.

Other animals and plants

Wall lizard in the area of ​​the pit field

In addition to bats, there are some other rare animal and plant species that are particularly worthy of protection:

The extraordinary underground basalt caves of Mayen and Mendig have been populated by some endemic animal species that are almost unique in Germany . In 1999 a species of cave horror was discovered in the caves that has so far only been found in very few other caves in Germany. Unusual spiders also live here, e.g. B. the Weberknecht species Leiobunum religiosum , which is otherwise only widespread in the Alpine and Mediterranean regions.

Between the rocks lumps on the dry grasslands live in damp caves and in the water holes of the overgrown quarries numerous reptiles ( Emerald -, masonry and sand lizards , slow worms , annelids and smooth snakes ) and amphibians ( earthworks , cross and midwife toad , ...).

The sunny, poor grasslands and ruderal corridors of the pit field also offer a habitat for many insects, including many butterflies (e.g. the rare Spanish flag ), grasshoppers , wild bees and wasps, ... Several large insect hotels have been set up in the pit field for demonstration for visitors and for observation .

Furthermore, the Mayener pit field with its special conditions is a breeding area for some rare bird species such as woodlarks or black warblers . The eagle owl also breeds in the Mayen basalt quarries.

Information center Erlebniswelten Grubenfeld

In 2012, the "Terra Vulcania Adventure Center" was opened on the edge of the Mayen mine field as part of the volcano park . This had to be renamed "Erlebniswelten Grubenfeld" in winter 2018/19. In this visitor center , the geology and above all the volcanism of the region is presented and information is provided on the history of basalt mining, the use of the rub, mill and stone stones as well as the animals and plants living in the area of ​​the mine field today. The exhibition is designed to be understandable for children and visitors can interactively experience the work of miners and stonemasons in the mine field.

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  Exhibition, interior

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  Various millstones and cut stones made of basalt in the outdoor area

Lapidea Sculpture Park

Some of the numerous Lapidea sculptures in the pit field

Between 1985 and 2006, the association Förderkreis Natursteine ​​Mayen , from which the Lapidea Foundation for Art and Culture later emerged, held the Lapidea symposium for stonecutters and stone sculptors from all over the world every three years in Mayen .

A large number of sculptures made of Mayen basalt and other volcanic materials from the region were created as part of these symposia . The majority of it was or is to this day exhibited in the area of ​​the mine field for visitors and prospective buyers and can be viewed free of charge. Some of the works have since been sold and have been transported away. Another part was set up along the Maifeld cycle path .

Participants in the symposium included the contemporary artists Thomas Resetarits , Wilfried Behre , Kang Jinmo , Susanne Specht , Heike Schaefer , Peter Rübsam , Elisabeth Juan , Yoshimi Hashimoto , Colin Foster , Jon Barlow Hudson , Luciano Massari , Peter Roller , Georg Miks , Tanja Preminger , Bernd Bodechtel .

literature

→ See also: Fridolin Listeners: Bibliography of Mayen and the surrounding area (=  basics of local history . Volume 1 ). 3. Edition. History and antiquity associations for Mayen and the surrounding area eV, Mayen 2002, especially chapter 3.3 Mining and stone industries ( full text as PDF ; 541 kB).

• Hans Schüller: Basalt lava operation between the Rhine and Eifel (=  the series of working environments ). Sutton Verlag , Erfurt 2007, ISBN 978-3-86680-196-7 ( limited preview in the Google book search).
• E. Harms, F. Mangartz: From magma to millstone. A journey through time through the lava flows of the Bellerberg volcano (=  volcano park research . Volume 5 ). Roman-Germanic Central Museum, Mainz 2002.
• Berthold Prössler: Mayen in the Empire, 1871–1914: Basalt lava operation and political-social conditions . History and Antiquity association f. Mayen et al. Environment, 1991, ISBN 3-930821-05-2 .
• Meinard Pohl: Rich in stone. Millstones, tuff and trass from the eastern Vulkaneifel and their market . Dissertation. German Mining Museum, Bochum 2012, ISBN 978-3-937203-61-4 .
• Schulze: The millstone quarries between Mayen and Lake Laacher . In: Carl JB Karsten (Ed.): Archives for mining and metallurgy . tape 17 . Reimer, 1828, p. 386–432 ( full text in Google Book Search).
• Jan Ludwig: Rhenish basalt industry and road construction in Germany . In: Hans-Liudger Dienel (Ed.): The modern road: planning, construction and traffic from the 18th to the 20th century (=  contributions to the historical traffic research of the German Museum ). tape 11 . Campus Verlag, 2010, ISBN 978-3-593-39157-1 , pp. 101–118 ( limited preview in Google Book search).
• Fritz Mangartz: Roman basalt lava mining between Eifel and Rhine (=  monographs of the Roman-Germanic Central Museum . Volume 75 ). Schnell & Steiner, 2007, ISBN 978-3-7954-1859-5 .

Web links

Commons : Mayener Grubenfeld  - Collection of images, videos and audio files

Remarks

1. ↑ Note .: It this is not a mining claim in the mining law sense! The surface and near-day mining of basalt did not fall under mining law, but was considered to be excavation , i.e. H. the landowner (“heir”) was allowed to mine without a permit under mining law (source: Ludwig 2010). The Mayener pit field comprised numerous legally separate properties and associated pits.
2. ↑ ^{a b} Note: From a mining point of view, these are mostly not tunnels , but stretches , as these - at least originally - did not have a mouth hole , but started out from a shaft. For some, however, a floor opening was subsequently created so that they actually became a tunnel.

Individual evidence

1. ↑ ^{a b c d} Rainer Olzem: Eifel excursion - afternoon of the 2nd day of the excursion. June 19, 2011, accessed April 28, 2014 .  
2. ↑ The Mayener mine field. City of Mayen, accessed April 26, 2014 .  
3. ↑ ^{a b} Mayen basalt lava: A traditional and modern natural stone. MAYKO Natursteinwerke GmbH & Cie. KG, accessed on April 26, 2014 .  
4. ↑ ^{a b c} Securing underground facilities for former basalt mining in Mayen (Vordereifel). State Office for Geology and Mining of the State of Rhineland-Palatinate, accessed on April 25, 2014 .  
5. ↑ ^{a b c d e f} Schüller 2007 (see literature)
6. ↑ ^{a b c d} Ulrich Siewers: The Mayener mine field. Active Eastern Eifel - the Eastern Eifel experience, accessed on April 25, 2014 .  
7. ↑ ^{a b c} Mayener Grubenfeld: Let's hang! NABU Rheinland-Pfalz, accessed on April 25, 2014 .  
8. ↑ ^{a b c d e} Bat Conservation Working Group, NABU Rhineland-Palatinate (ed.): The underground basalt pits in Mayen and Niedermendig: "the beating heart of the Central European bat populations" . August 2003 ( download as PDF ).
9. ↑ ^{a b c} The Mayener mine field. Vulkanpark, accessed April 25, 2014 .  
10. ↑ ^{a b c} Lapidea Foundation for Art and Culture. Retrieved April 30, 2014 .  
11. ^ ^{A b c} Christoph M. Frisch: Mayen, Vulkanpark Eifel: The Mayener pit field. Industrial Culture Views, 2012, accessed April 25, 2014 .  
12. ↑ ^{a b} Fritz Mangartz: The quarries of the Bellerberg volcano from prehistory to the Middle Ages . In: Johannes Netz, MAYKO Natursteinwerke GmbH & Cie. KG (Hrsg.): Mayener Basaltlava - contemporary witness from the depths of the Vulkaneifel: a natural stone makes history; Festschrift for the 100th anniversary of MAYKO Natursteinwerke GmbH & Cie. KG . MAYKO, Mayen 2008, ISBN 978-3-00-025591-5 ( reading sample as PDF ).
13. ↑ ^{a b} Millstones were the first "export hit" from the Eifel. Europe's researchers look to Mayen - Dr. Fritz Mangartz presents a standard work on volcano research . In: Rhein-Zeitung, Koblenz edition . November 28, 2008 ( full text online at the Stiftung Zukunft der Sparkasse Koblenz ).
14. ^ ^{A b c d e} Karl-Heinz Schumacher, Wilhelm Meyer: Geopark Vulkanland Eifel - Lava Dome and Lava Cellar in Mendig . In: Mining . No. 3/2013 , p. 113-123 . Full text as PDF ( Memento from July 17, 2013 in the Internet Archive )
15. ↑ Christian Fuchs: Development of the grain mills. Steinzeit & Co. (www.steinzeitwissen.de), accessed on May 6, 2014 .  
16. ↑ ^{a b} Fritz Mangartz: A sample of Iron Age hard basalt grooved mallets ... In: Yearbook of the Römisch-Germanisches Zentralmuseum . Vol. 57, 2010, p. 63–121 ( full text as PDF ).
17. ↑ ^{a b} Tatjana Mirjam Gluhak: Petrological-geochemical characterization of Quaternary lavas of the Eifel as a basis for the archaeometric determination of the origin of Roman millstones . Dissertation to obtain the degree "Doctor of Natural Sciences" in the doctoral subject Mineralogy at the Department of Chemistry, Pharmacy and Geosciences at Johannes Gutenberg University Mainz. Mainz 2010 ( full text as PDF ).
18. ↑ ^{a b} Martin Thull: Mining of tufa: Like the Romans in the mine. Aachener Zeitung (Online), April 12, 2014, accessed on May 5, 2014 .  
19. ↑ ^{a b} Ancient sites: Mayener pit field. Mos Maiorum on WordPress , accessed April 28, 2014 .  
20. ↑ ^{a b c d e f g h i j k} Luise Grundmann: The Middle Rhine Basin: a regional study in the Andernach, Bendorf, Koblenz, Mayen, Mendig, Münstermaifeld and Neuwied area . Ed .: Frauke Gränitz (=  Landscapes in Germany - Values ​​of the German Homeland . Volume 65 ). Böhlau-Verlag, Köln / Weimar 2003, ISBN 978-3-412-10102-2 ( limited preview in the Google book search).
21. ↑ ^{a b c} Schulze 1828 (see literature)
22. ↑ ^{a b c} Bergmannsschacht im Grubenfeld: "Schacht 700" driving center on display. Press release. (No longer available online.) Mayen-Koblenz district administration, April 7, 2014, formerly in the original ; Retrieved April 28, 2014 .  ( Page no longer available , search in web archives )  
23. ↑ Ludwig 2010 (see literature)
24. ↑ Excursus: Beer and Basalt. Beer cellar. History & Antiquity Association GAV Mayen, accessed on May 6, 2014 .  
25. ↑ ^{a b} Shaft 700 in the Mayener mine field is open . In: Rhein-Zeitung , local section Mayen / Andernach . April 17, 2014 ( full text in the Rhein-Zeitung's online archive ).
26. ↑ ^{a b} Irene Quaile: A cozy meeting place for bats. Deutsche Welle, May 8, 2011, accessed April 28, 2014 .  
27. ↑ ^{a b} Mayener Grubenfeld: Hibernating bats can come. Press release. (No longer available online.) Ministry for the Environment, Agriculture, Food, Viticulture and Forests Rhineland-Palatinate, October 14, 2010, archived from the original on July 14, 2014 ; Retrieved May 7, 2014 .  
28. ↑ ^{a b c} Subterranean disused basalt mines Mayen and Niedermendig. EUNIS database of the European Environment Agency EEA, accessed on April 28, 2014 .  
29. ↑ ^{a b c} Nature Conservation Administration Rhineland-Palatinate: FFH 5609-301 “Underground, disused basalt mines Mayen and Niedermendig” . Profile of the FFH area. Ministry for the Environment, Agriculture, Food, Viticulture and Forests Rhineland-Palatinate ( download as PDF ).
30. ↑ ^{a b c} Hartmut Netz: Lots of space for bats. With 100,000 animals, the Mayener Grubenfeld is Germany's largest winter quarters . In: Conservation Today . Issue 2/2008 ( full text online ).
31. ↑ World Database on Protected Areas - Underground, disused basalt mines Mayen and Niedermendig Site of Community Importance (Habitats Directive) (English)
32. ↑ ^{a b Major} nature conservation project “Mayener Grubenfeld” completed. Press release. (No longer available online.) Ministry for the Environment, Agriculture, Food, Viticulture and Forests Rhineland-Palatinate, May 2, 2014, archived from the original on July 14, 2014 ; Retrieved May 7, 2014 .  
33. ↑ Mayener Grubenfeld is to become a nature reserve . In: Rhein-Zeitung , local section Mayen / Andernach . August 14, 2013 ( full text in the Rhein-Zeitung's online archive ).
34. ↑ ^{a b c d} Mayener Grubenfeld: Protection status goes into the next procedural section. (No longer available online.) SGD North Rhineland-Palatinate, formerly in the original ; Retrieved April 25, 2014 .  ( Page no longer available , search in web archives )  
35. ↑ Mayener Grubenfeld: nature reserve for 100,000 bats . In: Rhein-Zeitung . May 3, 2014 ( full text in the Rhein-Zeitung's online archive ).
36. ↑ Housing for 100,000 bats now a nature reserve. (No longer available online.) Stern online (stern.de), May 3, 2014, formerly in the original ; Retrieved May 7, 2014 .  ( Page no longer available , search in web archives )  
37. ↑ Mayener Grubenfeld: Bat quarter becomes a nature reserve. SWR Landesschau Rheinland-Pfalz aktuell, May 2, 2014, accessed on May 7, 2014 .  
38. ↑ Great horseshoe bat hibernates for the first time in Mayener Grubenf. Retrieved June 23, 2017 . 
39. ↑ ^{a b} In the Green - Eco Tour: Invitation to the Underworld. SWR-Odysso, from broadcast Im Grünen . SWR television in Rhineland-Palatinate, August 11, 2009, accessed on May 5, 2014 .  
40. ↑ Grubenfeld bat quarters. City of Mayen, accessed May 7, 2014 .  
41. ↑ Ruth Petermann (arrangement): Bat Conservation in Europe II . Resolutions of the 5th and 6th EUROBATS Conference of the Parties and reports on bat protection in Germany 2003–2009. Ed .: Federal Agency for Nature Conservation (=  BfN scripts . Volume 296 ). Federal Ministry of the Environment (BMU printing company), Bonn - Bad Godesberg 2011, ISBN 978-3-89624-031-6 ( full text as PDF ).
42. ↑ Record stocks, preserve habitats: locust protection in NABU and LBV. NABU, accessed May 6, 2014 . 
43. ↑ The spider Leiobunum religiosum: Eerie giant crawlers. SWR Odysso, report on the program Im Grünen . SWR television in Rhineland-Palatinate, July 28, 2009, accessed on May 7, 2014 .  
44. ↑ ^{a b} Dirk Liesemer : Noah's Ark made of stone . In: nature . November 2013 ( full text online on the author's homepage ). Full text online on the author's homepage ( Memento from April 19, 2015 in the Internet Archive )
45. ↑ Bettina Köhl: Mayener Grubenfeld: Terra Vulcania Adventure Center is the youngest part of the volcano park . In: General-Anzeiger . Bonn August 24, 2013 ( full text in the GA's online archive ).