Billingen
Encyclopedia
Billingen is the largest of the thirteen mesa
s in the Swedish
county
of Västra Götaland, with a maximum altitude of 299 metres (981 ft). The mesa extends in a north-southerly direct with a length of 23 kilometres (14.3 mi) and a width of 11 kilometres (6.8 mi).
Billingen is divided into two parts by an east-west valley between Skövde
and Varnhem
. The mesa plateau is covered with vast forests and moorlands, including the nature reserve Blängsmossen with its unique flora.
The limestone
at Billingen has been quarried
for a long time for concrete manufacturing
; diabase
is also still quarried there;
The mesa, located between the two great lakes Vänern
and Vättern
, is also a popular nature resort with several nearby hotels, and an annual orienteering
tournament is held here . The town of Skövde
is built partially on the slopes of Billingens and the town center lies at the foot of the mesa.
Some additional local points of interest are Jättadalen (a dramatic ravine
with a waterfall
), Silverfallen, and the "caves of Ryd" which are better described as free-standing pillars of diabase.
deposited during the Cambrian
, Ordovician
and Silurian
periods (542 to 432 Ma), and a diabasic
intrusion
associated with the Oslo Rift
in the Permian
period.
The bedding sequence begins with the crystalline bedrock
of the Baltic Shield
, followed by sandstone
from the File Hajdar formation, uranium
-rich alum shale
, limestone
, slate
and a topmost 40 metres (131.2 ft) layer of diabase
, known locally as trapp (see deccan traps
). The hard diabase layer resisted the glacial erosion of the last ice age.
Mesa
A mesa or table mountain is an elevated area of land with a flat top and sides that are usually steep cliffs. It takes its name from its characteristic table-top shape....
s in the Swedish
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
county
Counties of Sweden
The Counties of Sweden are the first level administrative and political subdivisions of Sweden. Sweden is divided into 21 counties. The counties were established in 1634 on Count Axel Oxenstierna's initiative, superseding the historical provinces of Sweden to introduce a modern administration...
of Västra Götaland, with a maximum altitude of 299 metres (981 ft). The mesa extends in a north-southerly direct with a length of 23 kilometres (14.3 mi) and a width of 11 kilometres (6.8 mi).
Billingen is divided into two parts by an east-west valley between Skövde
Skövde
Skövde is a locality and the seat of Skövde Municipality, Västra Götaland County, Sweden with 34 446 inhabitants .Skövde is situated some 150 km northeast of Gothenburg, between Sweden's two largest lakes, Vänern and Vättern. It sits on the eastern slope of a low mountain ridge Billingen ,...
and Varnhem
Varnhem
Varnhem is a locality situated in Skara Municipality, Västra Götaland County, Sweden with 718 inhabitants in 2005.Varnhem is the location of the oldest known stone church in Sweden outside of Scania, erected in the 1040s at the latest...
. The mesa plateau is covered with vast forests and moorlands, including the nature reserve Blängsmossen with its unique flora.
The limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
at Billingen has been quarried
Quarry
A quarry is a type of open-pit mine from which rock or minerals are extracted. Quarries are generally used for extracting building materials, such as dimension stone, construction aggregate, riprap, sand, and gravel. They are often collocated with concrete and asphalt plants due to the requirement...
for a long time for concrete manufacturing
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
; diabase
Diabase
Diabase or dolerite is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. In North American usage, the term diabase refers to the fresh rock, whilst elsewhere the term dolerite is used for the fresh rock and diabase refers to altered material...
is also still quarried there;
The mesa, located between the two great lakes Vänern
Vänern
Vänern is the largest lake in Sweden, the largest lake in the EU and the third largest lake in Europe after Ladoga and Onega in Russia. It is located in the provinces of Västergötland, Dalsland, and Värmland in the southwest of the country.- History :...
and Vättern
Vättern
Vättern is the second largest lake in Sweden, after Lake Vänern and the sixth largest lake in Europe. It is a long, finger-shaped body of fresh water in south central Sweden to the southeast of Vänern pointing at the tip of Scandinavia....
, is also a popular nature resort with several nearby hotels, and an annual orienteering
Orienteering
Orienteering is a family of sports that requires navigational skills using a map and compass to navigate from point to point in diverse and usually unfamiliar terrain, and normally moving at speed. Participants are given a topographical map, usually a specially prepared orienteering map, which they...
tournament is held here . The town of Skövde
Skövde
Skövde is a locality and the seat of Skövde Municipality, Västra Götaland County, Sweden with 34 446 inhabitants .Skövde is situated some 150 km northeast of Gothenburg, between Sweden's two largest lakes, Vänern and Vättern. It sits on the eastern slope of a low mountain ridge Billingen ,...
is built partially on the slopes of Billingens and the town center lies at the foot of the mesa.
Some additional local points of interest are Jättadalen (a dramatic ravine
Ravine
A ravine is a landform narrower than a canyon and is often the product of streamcutting erosion. Ravines are typically classified as larger in scale than gullies, although smaller than valleys. A ravine is generally a fluvial slope landform of relatively steep sides, on the order of twenty to...
with a waterfall
Waterfall
A waterfall is a place where flowing water rapidly drops in elevation as it flows over a steep region or a cliff.-Formation:Waterfalls are commonly formed when a river is young. At these times the channel is often narrow and deep. When the river courses over resistant bedrock, erosion happens...
), Silverfallen, and the "caves of Ryd" which are better described as free-standing pillars of diabase.
Geology
Billingen, like most of the other mesas in Västergötland, consists of sedimentary rockSedimentary rock
Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
deposited during the Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
, Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
and Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
periods (542 to 432 Ma), and a diabasic
Diabase
Diabase or dolerite is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. In North American usage, the term diabase refers to the fresh rock, whilst elsewhere the term dolerite is used for the fresh rock and diabase refers to altered material...
intrusion
Intrusion
An intrusion is liquid rock that forms under Earth's surface. Magma from under the surface is slowly pushed up from deep within the earth into any cracks or spaces it can find, sometimes pushing existing country rock out of the way, a process that can take millions of years. As the rock slowly...
associated with the Oslo Rift
Oslo Graben
The Oslo Graben or Oslo Rift is a graben formed during a geologic rifting event in Permian time, the last phase of the Variscan orogeny. The main graben forming period began in the late Carboniferous, which culminated with rift formation and volcanism, with associated rhomb porphyry lava flows...
in the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
period.
The bedding sequence begins with the crystalline bedrock
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...
of the Baltic Shield
Baltic Shield
The Baltic Shield is located in Fennoscandia , northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton...
, followed by 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,...
from the File Hajdar formation, uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
-rich alum shale
Alum shale
Alum shale is a variety of shale or clay slate containing pyrites. Decomposition of pyrite by weathering forms sulfuric acid, which acts on potash and alumina constituents to form alum, often efflorescences on the rock.Alum shale contains kerogen originated from algae...
, limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
, slate
Slate
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering...
and a topmost 40 metres (131.2 ft) layer of diabase
Diabase
Diabase or dolerite is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. In North American usage, the term diabase refers to the fresh rock, whilst elsewhere the term dolerite is used for the fresh rock and diabase refers to altered material...
, known locally as trapp (see deccan traps
Deccan Traps
The Deccan Traps are a large igneous province located on the Deccan Plateau of west-central India and one of the largest volcanic features on Earth. They consist of multiple layers of solidified flood basalt that together are more than thick and cover an area of and a volume of...
). The hard diabase layer resisted the glacial erosion of the last ice age.