The Carpathian Flysch Belt is an arcuate tectonic zone included in the megastructural elevation of the Carpathians on the external periphery of the mountain chain. Geomorphologically it is a portion of the Outer Carpathians. Geologically it is a thin-skinned thrust belt or accretionary wedge, formed by rootless nappes consisting of so-called flysch – alternating marine deposits of claystones, shales and sandstones which were detached from their substratum and moved tens of kilometers to the north (generally). The Flysch Belt is together with Neogene volcanic complexes the only extant tectonic zone along the whole Carpathian arc.
The Carpathian Flysch Belt is connected to the flysch belt of the Alps (Rhenodanubian Flysch) and continues through the territory of the Czech Republic, Slovakia, Poland, Ukraine and Romania. The belt is about 1,300 km long and 60 – 75 km wide. [1] Sequences of the Flysch belt are thrusted over the margin of Carpathian foredeep in the north. The foreland of the Flysch belt is built by Bohemian Massif in the west, East-European Platform in the north and Moesian Platform in the east. In the south it is bounded by the Pieniny Klippen Belt in its western segment. The southern boundary of the Flysch Belt in the area of the Romanian Carpathians is covered by nappes of the crystalline-Mesozoic zone. [2]
The zone is primarily composed of sedimentary rocks which were deposited from the Upper Jurassic up to the Cretaceous-Paleogene periods. The Flysch Belt is structural remnant of several basins, developed in front of the advancing ancestral Carpathians and later incorporated in the Tertiary Carpathian fold and thrust belt. [3] The former sedimentary basin of the Carpathian Flysch belt was a portion of the Alpine Tethys Ocean. The present rocks are not in their former position because they were detached from their basement during the closure and subduction of basins and pushed as nappe pile, forming the Carpathian accretionary wedge. The fold axial planes have generally north vergence, north-western in the western sector, northern in the central sector and north-eastern to eastern in the eastern sector. Only the nappes of the South Carpathians have eastern to south-eastern vergence.
Approximately at the line of the Hodonín – Námestovo – Nowy Sacz – Neresnica distinct zone of negative gravimetric anomaly that follows the southern edge of the Bohemian Massif and East-European Platform, which are underthrust below the Carpathians. Anomalous crustal thickening, significant especially in southeastern Poland and western Ukraine, is probably caused by slab break off. The Earth's crust in this area reaches up to 65 km depth.
From the neotectonic point of view, the whole area of the Flysch belt is affected by extension, locally up to 12 mm per year.
Outer Carpathian tectonic units included in the Flysch Belt are divided according to their structural position in the frame of mountain range. Tectonic units vary not only in their structural position but also in differences in sedimentary sequences and other anomalies. Various tectonic divisions of the Flysch Belt were introduced. Generally these principal zones can be recognized: [4] [5]
Sedimentation in the basins of the Flysch Belt is recorded since the Upper Jurassic period up to Oligocene resp. beginning of Miocene. Basins of the Flysch zone were formed in the Middle Jurassic — Lower Cretaceous period of post-rift subsidence. During the Upper Cretaceous—Palaeocene time inversion locally occurred. In the most areas subsidence continued through the Palaeocene to Middle Eocene. Synorogenic closing of the basins followed in Upper Eocene–Lower Miocene. [6] Nappes are mostly composed of turbidites – alternating sandstones and claystones.
In the past it was believed that the source area of the clastic sediments supplied to the basins was built by a system of linear island elevations which were parallel to the axis of the mountain chain. [7] Although such conceptions still remain, recent interpretations assume that material was supplied by submarine canyons from the adjacent shelf areas (e.g. Nesvačilka canyon).
The nappes of the Flysch Belt were thrusted due to subduction of their basement and later formed and fold and thrust belt. The character of the lithosphere in former Flysch basins (oceanic, suboceanic or continental) is a matter of debate. Deformation of the belt was gradual. The area of the Magura Basin was deformed in the Upper Oligocene to Badenian (Middle Miocene). [8] The Silezian and Ždánice units were deformed in the Karpatian to Lower Badenian. The Moldavide Flysch was deformed since the Burdigalian, especially in Sarmatian and Badenian. Internal nappes show older Upper Cretaceous deformation. [5] Subduction of the Flysch Belt basement was generally south verging; internal units were therefore thrust over the external ones from the south to north (in the Western sector) or West to East (in Eastern sector). The tertiary shortening of the Flysch Belt is approximately 130–135 km. [9] Closure of the basins was connected with the motion of the Inner Carpathian crustal blocks so-called lateral extrusion to the East and Northeast [10] and intensive Calc-alkaline volcanism in the Carpathian internal zones. [11] Extrusion together with the movement into the “Carpathian embayment” was coeval with prominent rotation of Western Carpathian units in a counter-clockwise direction (up to 90°) and clockwise rotation of Eastern Carpathian units. Loading of the Flysch zone nappes forced subsidence in its foreland, causing formation of the Carpathian foredeep. Also, coeval back-arc extension occurred in the Pannonian region forming a half graben system Pannonian Basin.
The Carpathian Mountains or Carpathians are a range of mountains forming an arc across Central Europe. Roughly 1,500 km (930 mi) long, it is the third-longest European mountain range after the Urals at 2,500 km (1,600 mi) and the Scandinavian Mountains at 1,700 km (1,100 mi). The range stretches from the far eastern Czech Republic (3%) and Austria (1%) in the northwest through Slovakia (21%), Poland (10%), Ukraine (10%), Romania (50%) to Serbia (5%) in the south. The highest range within the Carpathians is known as the Tatra mountains in Poland and Slovakia, where the highest peaks exceed 2,600 m (8,500 ft). The second-highest range is the Southern Carpathians in Romania, where the highest peaks range between 2,500 m (8,200 ft) and 2,550 m (8,370 ft).
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.
The geology of the Himalayas is a record of the most dramatic and visible creations of the immense mountain range formed by plate tectonic forces and sculpted by weathering and erosion. The Himalayas, which stretch over 2400 km between the Namcha Barwa syntaxis at the eastern end of the mountain range and the Nanga Parbat syntaxis at the western end, are the result of an ongoing orogeny — the collision of the continental crust of two tectonic plates, namely, the Indian Plate thrusting into the Eurasian Plate. The Himalaya-Tibet region supplies fresh water for more than one-fifth of the world population, and accounts for a quarter of the global sedimentary budget. Topographically, the belt has many superlatives: the highest rate of uplift, the highest relief, among the highest erosion rates at 2–12 mm/yr, the source of some of the greatest rivers and the highest concentration of glaciers outside of the polar regions. This last feature earned the Himalaya its name, originating from the Sanskrit for "the abode of the snow".
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.
A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithosphere to bend, by a process known as lithospheric flexure. The width and depth of the foreland basin is determined by the flexural rigidity of the underlying lithosphere, and the characteristics of the mountain belt. The foreland basin receives sediment that is eroded off the adjacent mountain belt, filling with thick sedimentary successions that thin away from the mountain belt. Foreland basins represent an endmember basin type, the other being rift basins. Space for sediments is provided by loading and downflexure to form foreland basins, in contrast to rift basins, where accommodation space is generated by lithospheric extension.
The Western Carpathians are a mountain range and geomorphological province that forms the western part of the Carpathian Mountains.
The Strážov Mountains are a mountain range in northwestern Slovakia, being part of Inner Western Carpathians, and of the Fatra-Tatra Area. They are situated between the towns of Trenčín, Považská Bystrica, Rajec, Prievidza and Bánovce nad Bebravou, bordering White Carpathians and the Váh river in the northwest and west, Javorníky in the north, Malá Fatra in the east, Vtáčnik and Nitra river in the south and Považský Inovec in the southwest. The highest mountain is Strážov
The Fatra-Tatra Area or the Tatra-Fatra Belt of core mountains is a part of the Inner Western Carpathians, a subprovince of the Western Carpathians. Most of the area lies in Slovakia with small parts reaching into Austria and Poland. The highest summit of the whole Carpathians, the Gerlachovský štít at 2,655 m (8,711 ft), lies in the High Tatras range which belongs to this area.
The Pieniny Klippen Belt is in geology a tectonically and orographically remarkable zone in the Western Carpathians, with a very complex geological structure. It is a narrow and extremely long north banded zone of extreme shortening and sub-vertical strike-slip fault zone, with complex geological history, where only fragments of individual strata and facies are preserved. The Pieniny Klippen Belt is considered one of the main tectonic sutures of the Carpathians and forms the boundary between the Outer and Central Western Carpathians.
The Western Carpathians are an arc-shaped mountain range, the northern branch of the Alpine-Himalayan fold and thrust system called the Alpide belt, which evolved during the Alpine orogeny. In particular, their pre-Cenozoic evolution is very similar to that of the Eastern Alps, and they constitute a transition between the Eastern Alps and the Eastern Carpathians.
The Pyrenees are a 430-kilometre-long, roughly east–west striking, intracontinental mountain chain that divide France, Spain, and Andorra. The belt has an extended, polycyclic geological evolution dating back to the Precambrian. The chain's present configuration is due to the collision between the microcontinent Iberia and the southwestern promontory of the European Plate. The two continents were approaching each other since the onset of the Upper Cretaceous (Albian/Cenomanian) about 100 million years ago and were consequently colliding during the Paleogene (Eocene/Oligocene) 55 to 25 million years ago. After its uplift, the chain experienced intense erosion and isostatic readjustments. A cross-section through the chain shows an asymmetric flower-like structure with steeper dips on the French side. The Pyrenees are not solely the result of compressional forces, but also show an important sinistral shearing.
The Andean orogeny is an ongoing process of orogeny that began in the Early Jurassic and is responsible for the rise of the Andes mountains. The orogeny is driven by a reactivation of a long-lived subduction system along the western margin of South America. On a continental scale the Cretaceous and Oligocene were periods of re-arrangements in the orogeny. The details of the orogeny vary depending on the segment and the geological period considered.
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 Sicily records the collision of the Eurasian and the African plates during westward-dipping subduction of the African slab since late Oligocene. Major tectonic units are the Hyblean foreland, the Gela foredeep, the Apenninic-Maghrebian orogen, and the Calabrian Arc. The orogen represents a fold-thrust belt that folds Mesozoic carbonates, while a major volcanic unit is found in an eastern portion of the island. The collision of Africa and Eurasia is a retreating subduction system, such that the descending Africa is falling away from Eurasia, and Eurasia extends and fills the space as the African plate falls into the mantle, resulting in volcanic activity in Sicily and the formation of Tyrrhenian slab to the north.
The geology of Bosnia & Herzegovina is the study of rocks, minerals, water, landforms and geologic history in the country. The oldest rocks exposed at or near the surface date to the Paleozoic and the Precambrian geologic history of the region remains poorly understood. Complex assemblages of flysch, ophiolite, mélange and igneous plutons together with thick sedimentary units are a defining characteristic of the Dinaric Alps, also known as the Dinaride Mountains, which dominate much of the country's landscape.
The geology of Romania is structurally complex, with evidence of past crustal movements and the incorporation of different blocks or platforms to the edge of Europe, driving recent mountain building of the Carpathian Mountains. Romania is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders the Black Sea to the southeast, Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, and Moldova to the east.
The geology of Slovakia is structurally complex, with a highly varied array of mountain ranges and belts largely formed during the Paleozoic, Mesozoic and Cenozoic eras.
The geology of the Czech Republic is very tectonically complex, split between the Western Carpathian Mountains and the Bohemian Massif.
The Krempachy Marl Formation is a geological formation in Poland and Slovakia, dating to about 179 million years ago, and covering the middle Toarcian stage of the Jurassic Period. It is among the most important formations of the Toarcian boundary on the Carpathian realm, being the regional equivalent of the Posidonia Shale.
The geology of New Caledonia includes all major rock types, which here range in age from ~290 million years old (Ma) to recent. Their formation is driven by alternate plate collisions and rifting. The mantle-derived Eocene Peridotite Nappe is the most significant and widespread unit. The igneous unit consists of ore-rich ultramafic rocks thrust onto the main island. Mining of valuable metals from this unit has been an economical pillar of New Caledonia for more than a century.