The Lüneburg Kalkberg (not to be confused with the Segeberger Kalkberg) is the cap rock of a

salt dome A salt dome is a type of structural dome formed when salt (or other evaporite minerals) intrudes into overlying rocks in a process known as diapirism. Salt domes can have unique surface and subsurface structures, and they can be discovered us ...

in the western part of the German town of

Lüneburg Lüneburg, officially the Hanseatic City of Lüneburg and also known in English as Lunenburg, is a town in the German Bundesland (Germany), state of Lower Saxony. It is located about southeast of another Hanseatic League, Hanseatic city, Hambur ...

. The Kalkberg was a

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate Hydrate, dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk ...

mine during the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and ...

, but is today a ''

Naturschutzgebiet A ''Naturschutzgebiet'' (abbreviated NSG) is a category of protected area (nature reserve) within Germany's Federal Nature Conservation Act (the ''Bundesnaturschutzgesetz'' or ''BNatSchG''). Although often translated as 'Nature Reserve' in Engli ...

'' (nature reserve) and a common meeting place for city residents.

Composition and geology

The Kalkberg is made up largely of

(calcium sulphate) and comes from

sediments Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

that were deposited there around 250 million years ago by the Zechstein Sea. More recently (in geological terms), smaller disturbances have allowed the less dense Zechstein salts to flow together and force their way upwards into the younger, overlying rocks. Today these salts are near the Earth's surface. Through this process, the more geologically-recent layers of rock around the rising mass of salt were deformed, shattered, and lifted; the initially horizontally-lying layers of salt were tilted and folded as they were rose upwards. Near the surface, the resulting

was leached by

groundwater Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...

, so that only the less readily-soluble elements remained behind, such as

carbonates A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group . ...

and sulphates. These are the compounds that make up the Kalkberg today, and can also be seen to protrude through the surface around Lüneburg. Today, the rock walls only have very sparse vegetation, attracting animals and plants typical of dry

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

habitats. On an area of , one can find over 180 species of flowering plants, including several warmth-, light-, and chalk-loving types that otherwise grow only in south-central Europe. Several small caves are inhabited by

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

History

Until February 1371, a castle stood on top of the Kalkberg from where the Principality of Lüneburg-Brunswick was governed. During the

Lüneburg War of Succession Lüneburg, officially the Hanseatic City of Lüneburg and also known in English as Lunenburg, is a town in the German state of Lower Saxony. It is located about southeast of another Hanseatic city, Hamburg, and belongs to that city's wider met ...

, the castle on the Kalkberg was destroyed along with the nearby monastery. The bulk of the Kalkberg has been quarried away over the centuries in order to use the gypsum as a building material. The former quarry is still recognizable from its steep, rugged walls. As a result of the depletion of the salt deposits and the increasing

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

content of the gypsum, the quarry was closed in 1923. Of particular geological interest are deposits of

boracite Boracite is a magnesium borate mineral with formula: Mg3 B7 O13 Cl. It occurs as blue green, colorless, gray, yellow to white crystals in the orthorhombic - pyramidal crystal system. Boracite also shows pseudo-isometric cubical and octahedral fo ...

and lüneburgite. Other minerals present include

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

halite Halite ( ), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pi ...

hematite Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . ...

, hydroglauberite,

jarosite Jarosite is a basic hydrous sulfate of potassium and ferric iron (Fe-III) with a chemical formula of KFe3(SO4)2(OH)6. This sulfate mineral is formed in ore deposits by the oxidation of iron sulfides. Jarosite is often produced as a byproduct dur ...

, kalistronite,

lepidocrocite Lepidocrocite (γ-FeO(OH)), also called esmeraldite or hydrohematite, is an iron oxide-hydroxide mineral. Lepidocrocite has an orthorhombic crystal structure, a hardness of 5, specific gravity of 4, a submetallic luster and a yellow-brown stre ...

pyrite The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue ...

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

sylvite Sylvite, or sylvine, is potassium chloride (KCl) in natural mineral form. It forms crystals in the isometric system very similar to normal rock salt, halite ( NaCl). The two are, in fact, isomorphous. Sylvite is colorless to white with shades ...

, syngenite and thenardite. The Kalkberg still has a height of 56.3 m above

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

. Originally it was about 80 m high. The Lüneburg surveyor Eduard Schlöbcke helped turn the Kalkberg into one of the first German

nature reserves A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, funga, or features of geolog ...

in 1932.

Sources

* Eduard Schlöbcke: ''Der Kalkbergführer. 1000 Jahre Kalkberg und Gipsbruch in Lüneburg''. Lüneburg 1928 * Gerhard Stein: ''Der Lüneburger Kalkberg im Wandel der Zeiten''. in: Jahrbuch Naturwiss. Verein Fürstentum Lüneburg, Bd. 39, 247-258, Lüneburg 1992 * Erhard Poßin: ''Der Kalkberg'', Bd. 4 der ''Lüneburger Hefte'' Hrsg.: Backsteinprojekt e.V., Lüneburg, 2008

References

External links

Naturschutzgebiet "Kalkberg"
{{DEFAULTSORT:Luneburger Kalkberg Kalkberg Hills of Lower Saxony