In 2019 slate is “rock of the year” in Germany. This has just been communicated by the permanent committee for the “rock of the year”, working under the auspices of BDG Berufsverband Deutscher Geowissenschaftler e.V. (German Professional Association of Geoscientists). Slates are metamorphic rocks which emerge in a transformation process under high pressure and/or high temperature. Their most marked feature is their foliation which results in their excellent usability as stone slabs for walls and roofs.“Rock of the year” is an award which has been assigned to various rocks every year since 2007 to communicate rocks and geosciences into the public.
Today, slates, i.e. slate blackboards, and slate pencils, which were used by generations of schoolchildren up to the last century, have usually survived merely in museums (e.g., Deutsches Schiefermuseum – German Slate Museum – in Mayen/Eifel, or Schiefermuseum/Slate Museum in Ludwigsstadt, Upper Franconia).
But as elegant and durable roofing and cladding material or as cut stones to be used for staircases or in gardening slate is still highly appreciated.
Slates are rocks which emerge from clayey sediments through metamorphism (under high pressure and/or high temperature), which is sometimes accompanied by folding.
Slates show very good to excellent foliation along their slate surfaces. In contrast, non-metamorphic and usually finely-grained sediment rocks with a foliation similar to that of slate, which, however, is here due to alternating sediment layers, are called “shale”.
Slate had already been used for roofing in Ancient Rome. However, the golden age of roof slate was the Middle Ages and the Early Modern Age, when slate became so important that major mountain ridges were given its name, such as Rheinisches Schiefergebirge (Rhenish Slate Mountains) and Thüringer Schiefergebirge (Thuringia Slate Mountains).
Germany’s slate resources go back to the Paleozoic, usually to the Devonian and Carboniferous periods, which means that the slates are more than 300 million years old.
Still today, there are slate quarries and mines in Germany: in Geroldsgrün in Upper Franconia, where Lotharheiler slate is still being mined, in the Hunsrück Mountains (Altlay Slate Quarry), in the Sauerland Mountains (combine mine Magog-Gomer-Bierkeller, the slate of which is marketed as “Fredeburg” slate), and in Theuma near Plauen (Vogtland, Saxony, sold as “Theumaer Fruchtschiefer”). Despite high demand the Katzenberg slate mine near Mayen/Eifel will be closed this year, as the mining there is no longer profitable due to problems with the geology of the deposit.
Apart from roofing, slate is excellent for stone floorings and walls; it combines both heat and cold resistance with durability and beauty.
Slate, today, can be watched and experienced in geoparks and museums. A well-known slate location in Germany is Lehesten in Thuringia where the former quarry has been transformed into a geoscientific adventure park.
Another world-famous slate sight in Germany is the Loreley rock near St. Goarshausen in the Middle Rhine Valley, which is also a UNESCO world heritage site and best known from the legend and the poem of the “fair Loreley”.
The slate will be 'baptized' as 'rock of the year' in April this year, sometime around "Earth Day“ (22 April), in an active slate quarry, probably in the Eifel area. The slate year will be accompanied by publications on slate and geoscientific as well as artistic events featuring slate all over Germany.
Dr. Christof Ellger, GeoUnion, Christof.Ellger@geo-union.de
Dr. Manuel Lapp, Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, email@example.com
Dr. Christof Ellger | idw - Informationsdienst Wissenschaft
Most of Earth's carbon was hidden in the core during its formative years
02.04.2020 | Smithsonian
A sensational discovery: Traces of rainforests in West Antarctica
02.04.2020 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Electrolytes play a key role in many areas: They are crucial for the storage of energy in our body as well as in batteries. In order to release energy, ions - charged atoms - must move in a liquid such as water. Until now the precise mechanism by which they move through the atoms and molecules of the electrolyte has, however, remained largely unknown. Scientists at the Max Planck Institute for Polymer Research have now shown that the electrical resistance of an electrolyte, which is determined by the motion of ions, can be traced back to microscopic vibrations of these dissolved ions.
In chemistry, common table salt is also known as sodium chloride. If this salt is dissolved in water, sodium and chloride atoms dissolve as positively or...
Drops of water falling on or sliding over surfaces may leave behind traces of electrical charge, causing the drops to charge themselves. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz have now begun a detailed investigation into this phenomenon that accompanies us in every-day life. They developed a method to quantify the charge generation and additionally created a theoretical model to aid understanding. According to the scientists, the observed effect could be a source of generated power and an important building block for understanding frictional electricity.
Water drops sliding over non-conducting surfaces can be found everywhere in our lives: From the dripping of a coffee machine, to a rinse in the shower, to an...
90 million-year-old forest soil provides unexpected evidence for exceptionally warm climate near the South Pole in the Cretaceous
An international team of researchers led by geoscientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now...
The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply. When the iron transport into the bacteria is inhibited, the pathogen can no longer grow. This opens novel ways to develop targeted tuberculosis drugs.
One of the most devastating pathogens that lives inside human cells is Mycobacterium tuberculosis, the bacillus that causes tuberculosis. According to the...
An international team with the participation of Prof. Dr. Michael Kues from the Cluster of Excellence PhoenixD at Leibniz University Hannover has developed a new method for generating quantum-entangled photons in a spectral range of light that was previously inaccessible. The discovery can make the encryption of satellite-based communications much more secure in the future.
A 15-member research team from the UK, Germany and Japan has developed a new method for generating and detecting quantum-entangled photons at a wavelength of...
06.04.2020 | Event News
02.04.2020 | Event News
26.03.2020 | Event News
06.04.2020 | Life Sciences
06.04.2020 | Power and Electrical Engineering
06.04.2020 | Social Sciences