Cotta Sandstone (german: Cottaer Sandstein, also called ''Mittelquader''), is found in the Elbe Valley and in its numerous tributary valleys. Its main deposit lies in the west of the

Elbe Sandstone Mountains The Elbe Sandstone Mountains, also called the Elbe Sandstone Highlands (german: Elbsandsteingebirge; cs, Děčinská vrchovina), are a mountain range straddling the border between the state of Saxony in southeastern Germany and the North Bohemian ...

, where it runs up to the Bohemian border, ending south of

Pirna Pirna (; hsb, Pěrno; ) is a town in Saxony, Germany and capital of the administrative district Sächsische Schweiz-Osterzgebirge. The town's population is over 37,000. Pirna is located near Dresden and is an important district town as well as ...

. It is named after the village of Cotta in the borough of

Dohma Dohma is a municipality in the Sächsische Schweiz-Osterzgebirge district, in Saxony, Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe aft ...

, an area where the stone is quarried.

Formation and properties

Cotta Sandstone was formed in the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

, in the Lower

Turonian The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded ...

age. It is one of the Elbe sandstones and its colours range from whitish to grey and yellowish grey. In the south of the area Cotta Sandstone is medium-grained, whilst, in the north it is fine-grained. Around the village of Cotta itself the grain size is evenly sized at 0.1 to 0.22 millimetres and only very rarely as large as 0.3 millimetres. The rock contains the smallest elements of mica minerals (

glauconite Glauconite is an iron potassium phyllosilicate (mica group) mineral of characteristic green color which is very friable and has very low weathering resistance. It crystallizes with a monoclinic geometry. Its name is derived from the Greek () ...

), decomposed

feldspar Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feld ...

and carbon elements. The carbon particles are arranged in clearly recognisable veins. They occasionally resemble

marble Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorpho ...

textures. The technical value of this natural stone varies considerably, because the quartz grains of Cotta Sandstone are frequently siliceously bonded, but it has many unevenly divided deposits of the

phyllosilicates Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually cons ...

illite Illite is a group of closely related non-expanding clay minerals. Illite is a secondary mineral precipitate, and an example of a phyllosilicate, or layered alumino-silicate. Its structure is a 2:1 sandwich of silica tetrahedron (T) – alumina ...

and

kaolinite Kaolinite ( ) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is an important industrial mineral. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahed ...

Extraction

The stone is quarried in

(Groß-Cotta),

Bad Gottleuba-Berggießhübel Bad Gottleuba-Berggießhübel is a spa town in the district Sächsische Schweiz-Osterzgebirge in Saxony, Germany. The municipality borders the Czech Republic in the south. The municipality was formed on 1 January 1999 by the merger of the for ...

(in the villages of Gottleuba and Berggießhübel), Langhennersdorf,

Rottwerndorf Rottwerndorf is a village in the municipality of Pirna, in Saxony, Germany. It was incorporated into Pirna in 1923. The place was mentioned for the first time in 1337. It is situated on the river Gottleuba, south of Pirna town centre. The vil ...

, at Neundorf and Lohmgrund south of

, in Gersdorf and

Bahretal Bahretal is a municipality in the Sächsische Schweiz-Osterzgebirge district in Saxony, Germany. It is situated in the northeastern foothills of the Erzgebirge (''Ore Mountains''), between Bad Gottleuba-Berggießhübel and Dohna. It consist ...

(Ottendorf), and in the Krippenbach valley. The quarrying of Elbe sandstones is made technically easier because of the separation of the beds with alternating outcrops and fissures, because the fissures are vertical and the beds run roughly at right angles to them. As a result, it is possible to cut rectangular blocks of unfinished stone. The thickness of the quarry-able sandstone beds varies from a ½ to 3 metres. The thickness of the deposits of Cotta Sandstone ranges between 50 and 80 metres.

Use

General use

Formerly the sandstone quarried near Langhennersdorf, Berggießhübel and Gersdorf, which was larger-grained, was cut not only for use as building or sculpting stone, but also for millstones.Dienemann/Burre: Die nutzbaren Gesteine Deutschlands, p. 304 Today (2008) Cotta Sandstone is used for solid window and door frames,

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

work and high-profile stonemasonry. It is especially used in restoration, but also in new structures. Its most important use is for sculptures.

Gallery

File:Leipzig Reichsgericht.jpg, Reich Court building in Leipzig File:Dresden Zwinger.jpg, Dresdner Zwinger File:Berlin tu-berlin main-building 20050214 p1000596.jpg, TU Berlin File:Berlin UdK Fasanenstraße.jpg, University of Arts, Berlin, Fasanenstraße

Sources

* W. Dienemann und O. Burre: ''Die nutzbaren Gesteine Deutschlands und ihre Lagerstätten mit Ausnahme der Kohlen, Erze und Salze,'' Enke-Verlag, Stuttgart 1929. * Siegfried Grunert: ''Der Elbsandstein: Vorkommen, Verwendung, Eigenschaften''. In: Geologica Saxonica Journal of Central European Geology 52/53 (2007), p. 143-204
Digitalisat

External links

Technical data for Cotta Sandstone

References

Sandstone Elbe Sandstone Mountains Quarries in Germany