The Aarmassif or Aaremassif (German: ''Aarmassiv'') is a
geologic
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ear ...
massif
In geology, a massif ( or ) is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. The term also refers to a ...
in the
Swiss Alps
The Alpine region of Switzerland, conventionally referred to as the Swiss Alps (german: Schweizer Alpen, french: Alpes suisses, it, Alpi svizzere, rm, Alps svizras), represents a major natural feature of the country and is, along with the Sw ...
. It contains a number of large
mountain chain
A mountain chain is a row of high mountain summits, a linear sequence of interconnected or related mountains,Whittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, p 87. . or a contiguous ridge of mountains within a larger mo ...
s and parts of mountain chains.
Name
The massif is named after the
Aar
AAR or Aar may refer to:
Geography
*Aar, a river in Switzerland, tributary of the Rhine
* Aar (Lahn), a tributary of Lahn river in Germany, descending from the Taunus mountains
*Aar (Dill), a tributary of Dill river in Germany, also in the basi ...
, a river that has its source in the Aarmassif.
Geography
The Aarmassif
crops out in the eastern part of the
Bernese Alps
, topo_map= Swiss Federal Office of Topography swisstopo
, photo=BerneseAlps.jpg
, photo_caption=The Eiger, Mönch, and Jungfrau
, country= Switzerland
, subdivision1_type= Cantons
, subdivision1=
, parent= Western Alps
, borders_on=
, ...
and the
Lepontine Alps
, topo_map= Swiss Federal Office of Topography swisstopo
, photo=MonteLeone0001.jpg
, photo_caption=Monte Leone
, country_type= Countries
, country=
, subdivision1_type= Cantons, Regions
, subdivision1=
, parent= Western Alps
, borders ...
, roughly form
Leukerbad
Leukerbad (french: Loèche-les-Bains, Walliser German: ''Leiggerbad'', although locally known as ''Baadu'') is a municipality in the district of Leuk in the canton of Valais in Switzerland.
History
The story of Leukerbad dates back to the 4t ...
in the west to the
Tödi
The Tödi (), is a mountain massif and with the mountain peak Piz Russein the highest mountain in the Glarus Alps and the highest summit in the canton of Glarus, Switzerland. It is located on the border between the cantons of Graubünden, to th ...
in the east. Further east the massif only appears in small
windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ...
like the ''Vättner window'' between
Gigerwald and
Vättis in
Sankt Gallen and at the
Limmerensee
Limmernsee (or Limmerensee) is a reservoir in the Canton of Glarus, Switzerland, between the peaks of Muttenchopf (2,482 m), Selbsanft (2,950 m) and Kistenstöckli (2,746 m). It may be reached by aerial tramway or by foot from Linthal.
The L ...
in the same
canton
Canton may refer to:
Administrative division terminology
* Canton (administrative division), territorial/administrative division in some countries, notably Switzerland
* Township (Canada), known as ''canton'' in Canadian French
Arts and ente ...
.
Tectonics and lithology
The Aarmassif is part of the
Helvetic zone
{{Geology of the Alps
The Helvetic zone, Helvetic system or the Helveticum is a geologic subdivision of the Alps. The Helvetic zone crops out mainly in Switzerland, hence the name (derived from ''Helveticus'': Latin for Swiss). Rocks in the Hel ...
of the Alps, which consists of material originally from the European
tectonic plate
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large t ...
. The Aarmassif has
lithologies
The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lith ...
common for
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiós'' (, "old") and ' ...
basement
A basement or cellar is one or more Storey, floors of a building that are completely or partly below the storey, ground floor. It generally is used as a utility space for a building, where such items as the Furnace (house heating), furnace, ...
rocks all over Europe,
deformed and
metamorphosed
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...
during the
Variscan orogeny
The Variscan or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea.
Nomenclature
The name ''Variscan'', comes ...
. Younger
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...
sedimentary rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particle ...
s were
eroded
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
from this basement as a
thrust fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks.
Thrust geometry and nomenclature
Reverse faults
A thrust fault is a type of reverse fault that has a dip of 45 degrees or less.
If ...
brought the basement to the surface in the
Alpine orogeny. Other places, where the European basement crops out in the Helvetic zone, are the mountain chains of the
Massif des Écrins
The mountains of the Massif des Écrins (; Écrins Massif) form the core of Écrins National Park in Hautes-Alpes and Isère in the French Alps.Mont Blanc
Mont Blanc (french: Mont Blanc ; it, Monte Bianco , both meaning "white mountain") is the highest mountain in the Alps and Western Europe, rising above sea level. It is the second-most prominent mountain in Europe, after Mount Elbrus, and i ...
in the
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with France ...
and
Italian
Italian(s) may refer to:
* Anything of, from, or related to the people of Italy over the centuries
** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom
** Italian language, a Romance language
*** Regional Ita ...
Alps.
The
lithologies
The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lith ...
of the basement rocks are mainly
gneiss
Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures a ...
es,
schist
Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes ...
s and
amphibolite
Amphibolite () is a metamorphic rock that contains amphibole, especially hornblende and actinolite, as well as plagioclase feldspar, but with little or no quartz. It is typically dark-colored and dense, with a weakly foliated or schistose (flak ...
s. These were in some places intruded by
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Pale ...
granite
Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies und ...
s after the
Variscan orogeny
The Variscan or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea.
Nomenclature
The name ''Variscan'', comes ...
, called Aare granite. During a late phase in the Alpine orogeny in the
Tertiary
Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago.
The period began with the demise of the non- avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...
the Aarmassif was
uplifted
''Uplifted'' is the second studio album by Nigerian singer Flavour N'abania. It was released on July 20, 2010, by Obaino Music and 2nite Entertainment. The album features guest appearances from Jay Dey, Oloye, Stormrex, Waga Gee, Asemstone, M-Jay, ...
in the form of a large elongated
dome structure. The overlying limestones of the
Helvetic nappes {{Unreferenced, date=June 2019, bot=noref (GreenC bot)
The Helvetic nappes (german: Helvetische Decken) are a series of nappes in the Northern part of the Alps and part of the Helvetic zone. They consist of Mesozoic limestones, shales and marls tha ...
now have a very high
dip angle, forming a ridge that appears at the
Eiger
The Eiger () is a mountain of the Bernese Alps, overlooking Grindelwald and Lauterbrunnen in the Bernese Oberland of Switzerland, just north of the main watershed and border with Valais. It is the easternmost peak of a ridge crest that exte ...
and south of the
Jungfrau
The Jungfrau ( "maiden, virgin"), at is one of the main summits of the Bernese Alps, located between the northern canton of Bern and the southern canton of Valais, halfway between Interlaken and Fiesch. Together with the Eiger and Mönch, the ...
mountain.
See also
*
Infrahelvetic complex The Infrahelvetic complex is a tectonic unit in the Swiss Alps. It consists of autochthonous rocks of the former southern continental margin of the European Plate.
The Infrahelvetic complex has been overthrusted by the Helvetic nappes, that partl ...
Geology of the Alps
Geology of Switzerland
Lepontine Alps
{{switzerland-geo-stub