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A longitudinal valley is an elongated valley found between two almost-parallel mountain chains in geologically young fold mountains, such as the Alps, Carpathians, Andes, or the highlands of Central Asia. They are often occupied and shaped by a subsequent stream.The term is frequently used if a mountain range also has prominent transverse valleys, where rivers cut through the mountain chains in so-called water gaps.
Many longitudinal valleys follow the strike of the rock strata or significant geological fault lines. These are formed in conjunction with the tectonic movements during mountain building, which in turn are due to plate tectonic processes. The faults are structures that reach deep into the lower part of the Earth's crust, which is already in place before the actual mountain building phase and is later reactivated. The Periadriatic Seam in the Alps is a good example of this. In the formation of longitudinal valleys, however, nappe overthrusts also play a major, if not the most important, role. The nappes that are present in many young fold mountain ranges are responsible to a large extent for the morphological division of a mountain belt into parallel chains. In such cases, longitudinal valleys generally run along the so-called leading edge of the nappe (the overthrust front) and are oriented at right angles to the direction of movement of the tectonic nappes, which in turn correspond to the direction of movement of the colliding continental blocks.
This configuration results in a course that runs with the strike of the geological units. This is an important criterion for the definition of a longitudinal valley. In contrast, a transverse valley cuts across the strike.
Particularly long valley systems that are occupied by several rivers, sometimes running in opposite directions, are known in German as Längstalfurchen ("longitudinal troughs"), as opposed to the usual Längstäler, although no such distinction is made in English. The Eastern Alps and other Alpine ranges have many such troughs, which are almost straight for a distance of several hundred miles and were accentuated by glacial processes during the Pleistocene.
The line of the Upper Rhone and Anterior Rhine valleys – albeit separated by the Furka and Oberalp Passes – can also be seen as a longitudinal trough.
The Alps form part of a Cenozoic orogenic belt of mountain chains, called the Alpide belt, that stretches through southern Europe and Asia from the Atlantic all the way to the Himalayas. This belt of mountain chains was formed during the Alpine orogeny. A gap in these mountain chains in central Europe separates the Alps from the Carpathians to the east. Orogeny took place continuously and tectonic subsidence has produced the gaps in between.
A mountain chain is a row of high mountain summits, a linear sequence of interconnected or related mountains, or a contiguous ridge of mountains within a larger mountain range. The term is also used for elongated fold mountains with several parallel chains.
The Salzach is a river in Austria and Germany. It is a right tributary of the Inn and is 227 kilometres (141 mi) in length, its flow eventually joins the Danube. Its drainage basin of 6,829 km2 (2,637 sq mi) comprises large parts of the Northern Limestone and Central Eastern Alps. 83% of its drainage basin lies in Austria, the remainder in Germany (Bavaria). Its largest tributaries are Lammer, Berchtesgadener Ache, Saalach, Sur and Götzinger Achen.
The Kitzbühel Alps are a mountain range of the Central Eastern Alps surrounding the town of Kitzbühel in Tyrol, Austria. Geologically they are part of the western slate zone.
The Central Eastern Alps, also referred to as Austrian Central Alps or just Central Alps comprise the main chain of the Eastern Alps in Austria and the adjacent regions of Switzerland, Liechtenstein, Italy and Slovenia.
In geology, a nappe or thrust sheet is a large sheetlike body of rock that has been moved more than 2 km (1.2 mi) or 5 km (3.1 mi) above a thrust fault from its original position. Nappes form in compressional tectonic settings like continental collision zones or on the overriding plate in active subduction zones. Nappes form when a mass of rock is forced over another rock mass, typically on a low angle fault plane. The resulting structure may include large-scale recumbent folds, shearing along the fault plane, imbricate thrust stacks, fensters and klippe.
Eastern Alps is the name given to the eastern half of the Alps, usually defined as the area east of a line from Lake Constance and the Alpine Rhine valley up to the Splügen Pass at the Alpine divide and down the Liro River to Lake Como in the south. The peaks and mountain passes are lower than the Western Alps, while the range itself is broader and less arched.
The Radstadt Tauern are a subrange of the Central Eastern Alps in Austria. Together with the Schladming Tauern, the Rottenmann and Wölz Tauern and the Seckau Tauern the Radstadt Tauern form the major range of mountains known as the Low Tauern. The mountains are found in the southeast of the Austrian state of Salzburg, between the upper reaches of the Enns and Mur rivers.
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. Rocks in the Helvetic zone are sedimentary and were originally deposited at the southern margin of the European plate. The Helvetic zone correlates with the French Dauphinois zone, French geologists often prefer the French name but normally this is considered the same thing.
The Austroalpine nappes are a geological nappe stack in the European Alps. The Alps contain three such stacks, of which the Austroalpine nappes are structurally on top of the other two. The name Austroalpine means Southern Alpine, because these nappes crop out mainly in the Eastern Alps.
The Molasse basin is a foreland basin north of the Alps which formed during the Oligocene and Miocene epochs. The basin formed as a result of the flexure of the European plate under the weight of the orogenic wedge of the Alps that was forming to the south.
Décollement is a gliding plane between two rock masses, also known as a basal detachment fault. Décollements are a deformational structure, resulting in independent styles of deformation in the rocks above and below the fault. They are associated with both compressional settings and extensional settings.
The Western Carpathians are a mountain range and geomorphological province that forms the western part of the Carpathian Mountains.
Radstädter Tauern Pass is a high mountain pass in the Austrian state of Salzburg, connecting the town of Radstadt in the Pongau region with Mauterndorf in Lungau.
The Salzburg Slate Alps are a mountain range of the Eastern Alps, in the Austrian state of Salzburg. Situated within the greywacke zone, they could be regarded either as part of the Northern Limestone Alps or of the Central Eastern Alps.
The Hochschwab, Hochschwab Mountains, Hochschwab Alps or Hochschwab Group is a mountain range in the Northern Limestone Alps of Austria. The range is in the Styria. The highest peak is also called Hochschwab and is 2,277 metres above the Adriatic.
The Dachstein Mountains are a mountain range in the Northern Limestone Alps.
The Mürzsteg Alps or Mürztal Alps are a mountain range in the Eastern Alps, which lie in the Austrian state of Styria, with a small part of the range in Lower Austria. The highest peak is the Hohe Veitsch in the centre of the group, while largest massif is the Schneealpe in the northwest, near the Rax.
The geology of Germany is heavily influenced by several phases of orogeny in the Paleozoic and the Cenozoic, by sedimentation in shelf seas and epicontinental seas and on plains in the Permian and Mesozoic as well as by the Quaternary glaciations.
The geology of Austria consists of Precambrian rocks and minerals together with younger marine sedimentary rocks uplifted by the Alpine orogeny.