Mayener Grubenfeld

Mayener Lay - Mayener Ley - Mayener Leyen

Useful Information

Location:	An den Mühlsteinen 7, Mayen. (50.332800, 7.238345)
Open:	Grubenfeld: no restrictions. Schacht 700: APR to SEP no restrictions. Erlebniswelten: all year daily 10-17. [2021]
Fee:	Grubenfeld: frei. Erlebniswelten: Adults EUR 6, Children (-16) EUR 3,50, Children (<1 m) free, Students EUR 3,50, Disabled EUR 3,50, Families group price. Groups (20+): Adults EUR 4,50, Children (-16) EUR 2,60. [2021]
Classification:	Rock Mine Room and Pillar Mining Cellar
Light:	bring torch
Dimension:
Guided tours:	self guided
Photography:	allowed
Accessibility:	no
Bibliography:
Address:	Erlebniswelten Grubenfeld, An den Mühlsteinen 7, 56727 Mayen, Tel.: 02651 491506. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

5000 BC	first use of basalt for grinding.
3000 BC.	stone tools made of basalt.
1000 BC.	first, shallow quarry pits.
800 BC.	manufacture of rubbing stones and millstones.
55 BC.	Roman millstone production.
~1400	mining underground in pits.
1840	breweries move to Mayen and Mendig because of the rock cellars.
~1870	reduction of millstone blanks.
~1870	quarrying of millstone and building material in opencast mines.
1876	invention of the refrigerating machine by Carl von Linde.
1878	railway line opened from Andernach via Mendig to Mayen, primarily for basalt transport.
1900	extraction of millstone blanks completely abandoned due to inefficiency.
~1970	economically recoverable stocks exhausted, operation is discontinued.

Geology

The basalt deposits near Mayen were formed about 140,000 to 200,000 years ago, during the Quaternary period. The origin of the lava flows was the Bellerberg volcanic group, about 1,300 m north near Ettringen. The volcano erupted three times and viscous lava flowed into the Nette valley in at least three large-scale lava flows. The lava flow covered the surface of Devonian clay and shale between 10 and 30 m high. If the lava had been a little less viscous, it would probably have degassed completely, but so gas bubbles remained in the lava and solidified with it. The result is a very porous basalt with up to 25% bubble volume.

In later volcanic eruptions, the basalt was covered by a top layer of Dielsteiner Gebirge up to 10 metres thick. This is a breccia-like volcanic loose rock consisting of coarse trass with intercalated pieces of pumice, slag, and other stones. This layer has protected the basalt from weathering.

Description

The Mayener Grubenfeld is called Mayener Lay in the local dialect, Lay is the word for stone or rock, aner also for quarry. It appears in place names and also in proper names, the Lorelei is the Lore on the stone. In Mayen there is a mighty layer of basalt, formed by a lava flow from the Bellerberg to the north. What is special about this basalt is the high pore volume of up to 25 percent bubble volume. The bubbles are small and quite evenly distributed. This type of rock is ideal for grinding grain, because the bubbles have sharp edges when they are cut, which cut the material to be ground.

As early as the Neolithic period, about 7,000 years ago, this property of basalt was recognised and basalt stones found on the surface were used as rubbing stones. Grains were placed on a plate and ground with the rubbing stone. Obviously, at first only stones lying on the surface were collected, but later special blocks were also crushed with the help of wedges and levers. From 3000 BC, stone tools such as percussion balls, stone axes and hammers were made from harder basalt. From the Urnfield period, i.e. around 1000 BC, the first shallow quarry pits were driven into the basalt. With the Hallstatt and Latène periods around 800 BC, advanced rubbing stones, so-called Napoleon hats and the first simple millstones for hand-turning mills were produced. The Celts traded the stones from Mayen over long distances.

The Romans extended their empire to the Rhine around 55 BC in the Gallic War against the Germanic tribes. They soon became aware of the excellent suitability of Mayen basalt as a millstone and began systematic mining. Even then, up to 600 workers were working in the millstone quarries. They produced legionary mills, which the Roman army took with them on their war campaigns for daily rations, as well as large göpel mills. For this, the stone was hewn into an hourglass shape and placed on a cone. The grain was filled into the upper hopper and then the stone was turned on the cone, To drive it, a göpel was attached, which then had to be pulled in a circle by people or animals.

The Romans also intensified trade, the millstones were shipped from the Roman Rhine port in Andernach. They could be traced to Britain and the Mediterranean. But trade also took place across the Rhine, as finds in Haitabu in Schleswig Holstein show.

The Mayener Grubenfeld in its present form, however, originated in the Middle Ages, from the 15th century onwards. At that time, mining went underground. As the best basalt was buried under a 10 m thick surface layer, a shaft with a diameter of 7-8 m was sunk first. A stairway was hewn into the wall for descent and ascent. The shaft was used to lift out the finished millstones with a wooden crane driven by a göpel.

The underground cavities became larger and larger due to mining and the problem of collapse arose. On the one hand, the ceiling was supported in the classic chamber construction method by pillars that were not mined. However, this was supplemented by a unique technique that could only work here. The upper ends of the basalt columns were not dismantled and thus formed a honeycomb pattern on the ceiling. The dismantled parts of the columns were called rails, the upper ends bells. To prevent the bells from breaking out of the ridge, wooden wedges were hammered into the gaps, thereby bracing the bells. The resulting stable vault was called Geglöck.

Abandoned mines were popularly used by locals as rock cellars for storing perishable food. Breweries in particular use them as beer cellars for maturing and storing beer. The numerous rock cellars were so valuable to the breweries that numerous breweries settled in Mayen and Mendig from 1840 onwards. They lost their importance with the invention of the refrigeration machine by Carl von Linde in 1876. However, a few were still used until the middle of the 20th century, and later they were even rediscovered as a marketing gimmick.

The mining of millstones ended with the abolition of the many small wind and water mills in the second half of the 19th century. They were displaced by larger, modern mills that worked with roller mills, i.e. they did not need millstones. The demand for Mayen basalt millstones declined rapidly and around 1900 mining was completely abandoned. At the same time, however, the demand for basalt as a millstone and as a building material for railway and road construction increased. As a result, mining was completely converted and even intensified. The pits were abandoned and the basalt was again extracted in quarries.

The quarrying of paving stones, gravel, and so on, was done with simple hand tools. This method of working was very labour-intensive and before the First World War up to 1000 workers were employed in the Mayener Grubenfeld. It was only in the course of the next decades that electric cranes, pneumatic hammers, mechanical crushers and sorting machines were introduced. Electric saws were introduced for the production of large ashlar blocks. Mining ended in the 1970s because the deposits were exhausted.

About 100 ha of the former 1.5 km² mining district have been preserved in their historic state. This area is protected as a cultural monument and entered in the list of cultural monuments in Mayen. At the edge of the area, the Erlebniswelten Grubenfeld, a museum about the history of basalt mining, was opened. It was originally called Erlebniszentrum Terra Vulcania, but was sued by a volcano experience centre in Auvergne, France, because of the name. Therefore, the name had to be changed in 2018. The museum is open daily, and the mining district is open around the clock all year round. However, access to Shaft 700, a millstone mine with a modern access staircase, is only allowed from April to September. During winter, access is not permitted due to the Federal Nature Conservation Act (BNatSchG, §39, para. 6).