Elbe Sandstone
Encyclopedia
Elbe Sandstone describes sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

s that naturally occur in North Bohemia
North Bohemia
North Bohemia , is a region in the north of the Czech Republic.- Location :North Bohemia roughly covers the present-day NUTS regional unit of CZ04 Severozápad and the western part of CZ05 Severovýchod....

 and those parts of Saxony
Saxony
The Free State of Saxony is a landlocked state of Germany, contingent with Brandenburg, Saxony Anhalt, Thuringia, Bavaria, the Czech Republic and Poland. It is the tenth-largest German state in area, with of Germany's sixteen states....

 within the area around Dresden
Dresden
Dresden is the capital city of the Free State of Saxony in Germany. It is situated in a valley on the River Elbe, near the Czech border. The Dresden conurbation is part of the Saxon Triangle metropolitan area....

. It is named after the River Elbe, which cuts through the sandstone region in a transverse valley, the Elbe Valley Zone. It reaches the surface most strikingly in the Elbe Sandstone Mountains
Elbe Sandstone Mountains
The Elbe Sandstone Mountains, also called the Elbe sandstone highlands is a mountain range straddling the border between the state of Saxony in southeastern Germany and the North Bohemian region of the Czech Republic, with about three-quarters of the area lying on the German side...

, which are divided into the regions of Saxon Switzerland
Saxon Switzerland
Saxon Switzerland is a hilly climbing area and national park around the Elbe valley south-east of Dresden in Saxony, Germany. Together with the Bohemian Switzerland in the Czech Republic it forms the Elbe Sandstone Mountains....

 on German soil and Bohemian Switzerland on Czech territory. The term Elbe Sandstone is used in both geological and economic contexts.

Geological term

In a geological sense, Elbe Sandstone includes all sandstone types that occur in the region of the Elbe Valley
Elbe valley
The Elbe Valley is most often used as a term for that section of the river valley in which most of the quarters of Dresden are located. The Dresden Elbe Valley was declared a UNESCO World Heritage Site in 2005 and has lost the title June 25, 2009 due to a dispute between UNESCO and the City of...

 and were formed during the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 period. It consists mainly of quartz grains that are cemented by silica. The ratios and constituents of its accessory minerals are variable. Its deposits border on the area of the Lusatian Massif (Lusatian anticlinal zone), the Meißner Massif, the gneiss of the Eastern Ore Mountains
Eastern Ore Mountains
The Eastern Ore Mountains form a natural region that covers the eastern part of the Saxon Ore Mountains. It is part of the major landscape unit, the Saxon Highlands and Uplands...

, the Elbe Valley Slate Mountains and the territory of the Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

 by the northeastern foothills of the Central Bohemian Uplands and the fringe of the Eger Graben
Eger Graben
The Eger Graben is a geographical unit in the Czech Republic. It runs southwards, parallel to the Ore Mountains and its formation is linked with that of the mountain range.- Topography :...

.

Petrography of quarried Elbe sandstones

The bulk of the rock won in the quarries comprises sandstones with a silica cement. These are quartz sandstones, whose quartz grains have intermeshed crystal systems as a result of lithification (diagenesis
Diagenesis
In geology and oceanography, diagenesis is any chemical, physical, or biological change undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface alteration and metamorphism. These changes happen at relatively low temperatures and pressures...

) at their contact zones. Additional constituents include feldspar
Feldspar
Feldspars are a group of rock-forming tectosilicate minerals which make up as much as 60% of the Earth's crust....

, glauconite
Glauconite
Glauconite is an iron potassium phyllosilicate mineral of characteristic green color with very low weathering resistance and very friable.It crystallizes with a monoclinic geometry...

 and ferrous minerals of limonite
Limonite
Limonite is an ore consisting in a mixture of hydrated iron oxide-hydroxide of varying composition. The generic formula is frequently written as FeO·nH2O, although this is not entirely accurate as limonite often contains a varying amount of oxide compared to hydroxide.Together with hematite, it has...

 ore. In the pore space of sandstones of the Cotta type there are the fine-grained minerals of illite
Illite
Illite is a non-expanding, clay-sized, micaceous mineral. Illite is a phyllosilicate or layered alumino-silicate. Its structure is constituted by the repetition of tetrahedron – octahedron – tetrahedron layers. The interlayer space is mainly occupied by poorly hydrated potassium cations...

, kaolinite
Kaolinite
Kaolinite is a clay mineral, part of the group of industrial minerals, with the chemical composition Al2Si2O54. It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina octahedra...

 and quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

. The kaolinite comes from the chemical weathering of the feldspar (kaolinization). The SiO2
Silicon dioxide
The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...

 thus released contributes considerably to the mutual coalescence of the grains of sand. The pore spaces in sandstones of the Posta type for the most part contain no fillings.

Sandstone from Reinhardtsdorf
Reinhardtsdorf-Schöna
Reinhardtsdorf-Schöna is a municipality in the Sächsische Schweiz-Osterzgebirge district in the German federal state of Saxony. It has a population of approximately 1,600 and is located close to the Czech border in Saxon Switzerland, a popular tourist region....

 is an ashlar
Ashlar
Ashlar is prepared stone work of any type of stone. Masonry using such stones laid in parallel courses is known as ashlar masonry, whereas masonry using irregularly shaped stones is known as rubble masonry. Ashlar blocks are rectangular cuboid blocks that are masonry sculpted to have square edges...

 of the Cotta type with several properties of the Posta type.

In the past sandstone was won in a few quarries, now closed, that had a carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

 content. These sandstones came from deposits close to the surface and were only of low economic value.

The most important properties of these types of ashlar are derived from the presence or absence of fine-grained constituents.

Ashlar types

Hardened sand sediments of marine origin from the Upper Cretaceous form a sequence of several strata up to 400 metres thick. They have been quarried for centuries and used as ashlars. The deepest-lying, stratigraphically oldest layer is described as Mittelquader ("Middle Ashlar") or Cotta Sandstone
Cotta Sandstone
Cotta Sandstone , is found in the Elbe Valley and in its numerous tributary valleys. Its main deposit lies in the west of the Elbe Sandstone Mountains, where it runs up to the Bohemian border, ending south of Pirna...

, was formed in the Lower Turonian
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 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...

 and is mainly used as natural stone
STONe
is a Japanese manga written and illustrated by Sin-Ichi Hiromoto. Kodansha released the two bound volumes of the manga on April 23, 2002 and August 23, 2002, respectively.The manga is licensed for an English-languague released in North America be Tokyopop...

 for stone carving
Stone carving
Stone carving is an ancient activity where pieces of rough natural stone are shaped by the controlled removal of stone. Owing to the permanence of the material, evidence can be found that even the earliest societies indulged in some form of stone work....

.

Above that lies Oberquader ("Upper Ashlar") from the Middle Turonian, which is also known as Reinhardtsdorf Sandstone
Reinhardtsdorf Sandstone
Reinhardtsdorf Sandstone is quarried in the vicinity of Reinhardtsdorf near Pirna in the district of Sächsische Schweiz-Osterzgebirge in the German Free State of Saxony. It is the so-called main sandstone of the Elbe sandstones, and was formed in the Middle Turonian...

. It forms the main bulk of Elbe sandstone, but has only limited use. Similar to it, but of better quality, is Grillenburg Sandstone
Grillenburg Sandstone
Grillenburg Sandstone and Niederschöna Sandstone belong to the Elbe Sandstones of central Europe. There used to be a number of sandstone quarries in the Tharandt Forest and its neighbourhood, not far from Höckendorf and Ruppendorf, near Grillenburg, Niederschöna and Hetzdorf in the state of Saxony...

, that not only occurs in Saxon Switzerland, but also at the place of the same name in the Tharandt Forest
Tharandt Forest
The Tharandt Forest is a landscape in the centre of the German Free State of Saxony and lies southwest of the forest town of Tharandt, south of the town of Wilsdruff, roughly between the cities of Freiberg and Dresden...

 near Dresden
Dresden
Dresden is the capital city of the Free State of Saxony in Germany. It is situated in a valley on the River Elbe, near the Czech border. The Dresden conurbation is part of the Saxon Triangle metropolitan area....

, and, like Hetzdorf Sandstone, is one of the Niederschöna layers, that due to their formation within the Elbe Valley Chalk are counted as Elbe sandstones.

The uppermost, most recent layer is called Überquader ("Over Ashlar") or Posta Sandstone
Posta Sandstone
Posta Sandstone also called Wehlen Sandstone , only occurs on the eastern banks of the River Elbe at Alte Poste, near Herrenleithe, Wehlen, Zeichen and Posta. The thickness of the deposit is between 30 and 50 metres. It is also known as Überquader and has the smallest deposit of all the Elbe...

 and occurs, like the similar Wehlen Sandstone, only on the eastern bank of the Elbe. This variety from the Upper Turonian has a high strength and is used as a building stone, especially in a load-bearing role. It was used inter alia in the construction of the Church of Our Lady in Dresden. Similar to it are the sandstones from the Paulsdorf, Höckendorf and Dippoldiswald Heaths, not far from Dippoldiswalde
Dippoldiswalde
Dippoldiswalde is a town in the Free State of Saxony, Germany, administrative center of the Sächsische Schweiz-Osterzgebirge district. It is situated 23 km east of Freiberg, and 18 km south of Dresden....

 near Dresden.

Transport

For one of the main quarrying sites, the quarry in the Lohmgrund south of Pirna, the Pirna–Großcotta railway was built. Many of the quarries in the Elbe valley between Pirna and Tetschen
Decín
Děčín is a town in the Ústí nad Labem Region in the north of the Czech Republic. It is the largest town and administrative seat of the Děčín District.-Geography:...

 were able to ship their products either on the Elbe or on the Dresden–Děčín railway
Dresden–Děčín railway
The Dresden–Děčín railway, also called the Elbe Valley Railway is an important, electrified main line in Saxony and the Czech Republic. Formerly called the Saxon-Bohemian State Railway , the line is part of the Dresden to Prague route and is one of Europe's most important trunk routes...

.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK