Geology of the Western Carpathians

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Malá Studená Valley in the Tatras

The

Eastern Carpathians
.

The geological evolution of individual parts of the chain is complex, a result of

tectonic processes like folding, thrusting and the formation of sedimentary basins of various types during the Mesozoic and Cenozoic. These processes sometimes affected not only the sedimentary fill of the basins, but also, in some cases, the former basement
.

Many aspects of the geological structure of the Western Carpathians have not been completely studied and are subject to ongoing research and debate. The appropriate classification of a number of specific tectonic units is still not clear.

Geological definition

Geological position of the Western Carpathians in the Alpide belt.

The Western Carpathians are separated from the

lowlands of the Pannonian Basin). According to some views it is south of the Bükk and Mátra mountains in Hungary
.

Geological structure

There are several interpretations of the tectonic structure of the Western Carpathians. For quite a long time, the triple division has been used (

Inner Western Carpathians),[3][4][5][6] while some geologists prefer the classical double division (Outer and Inner Carpathians).[7][8][9] Other ideas of division may differ, such as morphotectonic (based on geology and geomorphology[3][8]) or regional geology.[5] Tectonic division applied in this article is based on the division of Plašienka and others[5] in 1997, later modified in 1999[6] and in 2002 together with Kováč,[10]
although it cannot be considered definitive.

The three main areas of the Inner, Central, and Outer Western Carpathians are divided by two

East European craton (Podolia platform). Since the 1980s the dividing line has been considered the suture of the Vahic Ocean – the Eastern continuation of the Piemont-Liguria Ocean.[4]

Tectonic map of the Western Carpathians
Tectonic map of the Western Carpathians

Foreland

The foreland of the Western Carpathians in the West and North is composed of the

Hercynian orogeny about 200 million years before the orogeny
in the Carpathians.

Outer Western Carpathians

The

Senonian) and Miocene periods, which is later than the Central Western Carpathians. Pieniny Klippen Belt was affected by thrusting together with the Central Carpathians and later folded and thrust again together with the Flysch Belt
.

Foredeep

Thrust of the Carpathians on their foreland caused a

sandstones and conglomerates that were formed in the Oligocene to Miocene periods by erosion of the growing Carpathians. Nevertheless, the foredeep is not generally folded; flysch nappes thrust from the south partially folded the rock underneath. The whole zone of the foredeep is developed in the foreland of the Alps, and runs through the Moravia to the Ostrava Basin and further East to Poland, Ukraine, and Romania
.

Flysch Belt

Crossection through the Western Carpathians

The

Carpathians. The Flysch Belt also contains a small volume of Cenozoic volcanic rocks. The zone originally consisted of a set of more sedimentary basins that were in constant tectonic transformation. Raised parts of the basins formed elevations, which were eroded and supplied deeper parts of the basin with clastic sediments that were brought by turbidity currents. Orogeny affected the area at the end of the Paleogene and in the beginning of the Neogene in the so-called Savian phase. Other portions were also affected by the Styrian phase, which caused partial thrusting over the Foredeep. Nappes were formed by gradual compression of the sedimentary basins that caused their inversion and separation of sedimentary successions from their basement and their movement for distance of 20 – 30 km, and possibly more. Nappes were formed in two phases: the outer (Northern) or lower group of nappes called the Silezia-Krosno Belt, and the overriding internal (Southern) Magura Belt. Nappes are thrust over their foreland in the form of tectonic slices. At least part of the Flysch Belt was an Eastern continuation of the Alpine Penninic Zone, probably the Valais branch. A direct continuation of the Alpine Rhine-Danube Flysch can be seen.[10] The Flysch Belt continues through Bohemia, Slovakia, and Poland, and joins the Moldavian Flysch in the Ukraine and Romania
.

Central Western Carpathians

The Central Western Carpathians, sometimes referred as the Slovakocarpathian system,

Outer Carpathians (represented by the Oravic). During the release of tension within the Alpine collision tectonic events, the stress
was released to the flanks of the thrust belt, which caused the tectonic escape of the material. Central Western Carpathians were consequently pushed in the Northeast direction from the Alpine to Carpathian domain.

Považie-Pieniny Belt

The Považie-Pieniny Belt has a complicated imbricated structure, represented especially by the Pieniny Klippen Belt.[6] It consists of Oravic, Gossau Group, and Magura units, as well as Inner-Carpathian units (e.g. Manín and Drietoma unit etc.). Placement of the Pieniny Klippen Belt into the Central Western Carpathians is ambiguous, because most authors consider Pieniny Klippen Belt as part of the Outer Carpathians.[3] The Považie-Pieniny Belt is divided into three zones: the Brezová, Peri-Klippen, and Klippen zones.

Trzy Korony, one of the largest klippes of the Kysuca-Pieniny unit, Poland.

Relatively thin and complicated, the

marls) were deformed in different ways, which caused the rupture of more dense rock and ductile deformation of the less dense rock. Complicated arrangement of particular tectonic units was later affected by strike-slip motion in the area of the Peri-Pieniny Lineament in the Miocene. Consequent erosion dissected the rigid limestone tectonic lenses to the shape of protruding klippes (e.g. Vršatské bradlá in Western Slovakia). The zone of klippes stretches almost uninterrupted from the Podbranč in Western Slovakia to the Poiana Botizei
in Northeastern Romanian.

Tatra-Fatra Belt of core mountains

Simplified cross-section through the Core mountain:
  Cenozoic cover
  Mesozoic nappes
  Autochthonous sedimentary cover
  Crystalline basement

South of the Pieniny Klippen Belt, the zone of core mountains is present. The core is formed by the

Nízke Tatry Mts. (so called Ďumbierske Tatry) and Branisko Mts.[12]

Vepor Belt

The

Vepor Mts., Kozie chrbty Mts., southern portion of the Branisko Mts. and Čierna hora Mts.[12] On the South it is divided from the Slovak Ore Mountains by the Lubeník-Margecany Line that is a gently dipping thrust fault
.

Gemer Belt

The

Upper Cretaceous, Silicic nappe was thrust over the previous. At the end of Paleogene, the Gemeric Belt was deformed and uplifted. This zone forms the Slovak Ore Mountains, Galmus, and Slovak Karst.[12]

Internal Western Carpathians

The Internal Western Carpathians are divided from the Central Western Carpathians by the Rožňava line, which is partly covered by the décollement nappes. The Rožňava line is largely a conceptual one and is perceived differently by different authors. According to assumptions, the fault joins the Raaba-Hurbanovo line on the West. Other problem of exact definition of boundary between the Internal and Central Western Carpathians are views of the structure of the Meliatic unit. The Internal Western Carpathians are composed generally of the tectonic units originating from the area of the former Meliata-Halstatt Ocean or South of it. This zone is built of the Meliata, Bükk, Transdanubian, and Zemplín Belt. There are large nappes of Mesozoic carbonates (Silicic, Meliatic, Tornaic), which are not affected by metamorphism and are characteristic with typical affinity to the South Alps-Dinaride facies.[6]

Meliata Belt

The

Wetterstein facies. The Tornaic nappe was probably a transitional area between the Silicic and Meliatic.[7] Nappes in the Meliata Belt were thrust to the North and now consist mostly of outliers lying on the Gemeric and Veporic units, constituting the Slovak Karst and Aggtelek Karst on the Slovak-Hungarian
border.

Bükk Belt

To the south of the previous area there is the

Upper Jurassic, the back-arc basin evolved. This basin was later inverted and it was probably the root zone of the Mónosbél-Szarvaskő nappe.[10]

Transdanubian Belt

The Transdanubian or the Bakony Belt principal tectonic unit called the

Vértes, and Buda Mountains). It consists of the low grade metamorphic Paleozoic and Mesozoic rock and Cenozoic sedimentary cover.[10]

Zemplín Belt

A tectonic unit of uncertain position is the

paragneisses, amphibolites, and migmatites, together with Post-Hercynian Carboniferous and Permian conglomerates and thin beds of black coal.[3]

Post-nappe units

The Jurassic-Cretaceous tectonic structure was later changed by various types of the overstep complexes: the Central Carpathian Paleogene Basin, Buda Paleogene Basin, Vienna Basin (Neogene, pull-apart type), Pannonian Basin (or the Danube Basin), and the volcanic complexes: Neogene volcanics of Carpathians (or just Neovolcanis).[12]

Volcanism

Paleozoic and Mesozoic volcanism

Permian andesitic-basalt with agate, so called melaphyry.

The oldest forms of volcanism, which affected the area of the Western Carpathians, are hardly recognized because of later tectonic processes and destruction by erosion.

Significant volcanic activity took place in the Lower Paleozoic in the

Tholeitic type in the upper part. Nodules of hydrothermal agate are common in the cavities of these rocks, widely known as the melaphyres. According to some authors, Permian volcanism in Hronic has polyphase linear character.[13]

Picrites are known around Banská Bystrica. Cretaceous těšínites (subvolcanic alkalic gabbro) were found in the Slesian zone of the Flysch Belt.[15] Remnants of destructed ophiolites with N-MORB basalts in the upper part are present in the rock of the Meliatic.[16]

Cenozoic volcanism

"Basalt waterfall" at Šomoška castle, Cerová vrchovina. Typical basaltic parting.

Post nappe volcanic activity in the Carpathians is simply called neovolcanism. It took place from the Neogene (Lower Badenian) to the Quaternary, mostly in the internal portion of the Carpathian arc (on a smaller scale also in the external Carpathians). Three main phases of the volcanic activity are distinguished:

Metamorphism

The occurrence of metamorphosed crystalline rock in the Western Carpathians is known from the

Cadomian or Caledonian metamorphic cycles,[18] existence of the Precambrian metamorphic cycles was not confirmed because of the later metamorphic overprint.[19]

Caledonian metamorphism has not been clearly proved, but some signs are present in

blueschist facies is known from the Bôrka nappe.[16]

Earthquakes

The Western Carpathians are from the

Pelso unit from the Inner Carpathian crystalline basement, the Žilina zone of earthquakes, related to the ongoing collision and strike-slip movement in the Pieniny Klippen Belt, and the Central Slovakia zone, which is probably the result of tectonic activity of the Central Slovak fault
.

Quaternary deposits

The

lateral moraines formed during the last glaciation and its immediate aftermath have been recognised in the Slovak Carpathians.[22]

References

  1. ^ a b Mísař, Z., 1987: Regionální geologie světa. Academia, Praha, 708 pp.
  2. ^ "On-line geologická encyklopedie". geology.cz. July 3, 2008.
  3. ^ a b c d e Mišík, M., Chlupáč, I., Cicha, I., 1984: Historická a stratigrafická geológia. Slovenské pedagogické nakladateľstvo, Bratislava, 541 pp.
  4. ^ a b c d e Maheľ, M., 1986: Geologická stavba československých Karpát. Paleoalpínske jednotky 1. Veda, Bratislava, 503 pp.
  5. ^ a b c d Plašienka, D., Grecula, P., Putiš, M., Kováč, M. a Hovorka, D., 1997: Evolution and structure of the Western Carpathians: an overview. Archived 2011-08-26 at the Wayback Machine in Grecula, P., Hovorka, D., Putiš, M. (Eds.) Geological evolution of the Western Carpathians. Mineralia Slovaca - Monograph, Košice, pp. 1 – 24
  6. ^ a b c d e Plašienka, D., 1999: Tektochronológia a paleotektonický model jursko-kriedového vývoja centrálnych Západných Karpát. Veda, 125 pp.
  7. ^ a b c d e Biely, A. (Editor) 1996: Explanation to geological map of Slovakia. Dionýz Štúr Publishers, Bratislava, 76 pp.
  8. ^ a b c Hók, J., Kahan, Š., Aubrecht, R., 2001: Geológia Slovenska. Archived 2011-07-19 at the Wayback Machine Univerzita Komenského, Bratislava, 43 pp.
  9. ^ a b Vozár, J., Vojtko, R., Sliva, Ľ., (Editors) 2002: Guide to geological excursion. XVIIth Congress of Carpathian-Balkan Geological Association. Dionýz Štúr Publishers, Geological survey of Slovak republic, Bratislava, 163 pp.
  10. ^ a b c d e Kováč, M., Plašianka, D., 2002: Geological structure of the Alpine-Carpathian-Pannonian junction and neighbouring slopes of the Bohemian Massif. Comenius University, Bratislava, 88 pp.
  11. ^ Tomek, Č., 1993: Deep crustal structure beneath the central and inner West Carpathians. Tectonophysics, 226, pp. 417–431
  12. ^ a b c d Plašienka, D. 2006: Princípy regionalizácie geologickej stavby Malých Karpát a Považského Inovca. In: Kováč, M., Dubíková, K., Nové metódy a výsledky v geológii Západných Karpát. Zborník 2006, pp. 51 – 56
  13. ^ a b Vozárová, A., Vozár, J., 1988: Late paleozoic in Western Carpathians. Geologický ústav Dionýza Štúra, Bratislava, 303 pp.
  14. ^ Putiš, M., Hrdlička, M. a Uher, P., 2004: Litológia a granitoidný magmatizmus staršieho paleozoika Malých Karpát. Mineralia Slovaca, 36, pp. 183 – 194
  15. ^ Hovorka, D., 1990: Sopky. Veda, Bratislava, 147 pp.
  16. ^ a b Ivan, P., 2002: Relics of the Meliata ocean crust: Geodynamic implications of mineralogical, petrological and geochmical proxies. Geologica Carpathica, 53, 4, s. 245–256
  17. ^ a b Konečný, V., Lexa, J., Šimon, L., Dublan, L., 2001: Neogénny vulkanizmus stredného Slovenska. Mineralia Slovaca 33, pp. 159–178
  18. ^ Putiš, M., Segeev, S., Ondrejka, M., Larionov, A., Siman, P., Spišiak, J., Uher, P., Paderin, I., 2008: Cambrian-Ordovician metaigneous rocks associated with Cadomian fragments in the West-Carpathian basement dated by SHRIMP on zircons: a record from the Gondwana active margin setting. Geologica Carpathica, 59, 1, pp. 3–18
  19. ^ Krist, E., Krivý, M., 1985: Petrológia. Alfa, Bratislava, 464 pp.
  20. ^ Krist, E., Korikovskij, S.P., Putiš, M., Janák, M., Faryad, S.W, 1992: Geology and petrology of metamorphic rocks of the Western Carpathian crystalline complexes. Comenius University Press, Bratislava, 324 pp.
  21. ^ Marko, F., 2004: Fault controlled evolution of the ALCAPA region. Geolines, 17, pp. 68–69
  22. ^ a b c d e Vaškovský, Imrich; Vaškovská, Eugenia (1981). "The development of the natural landscape in Slovakia during the Quaternary". Biuletyn Peryglacjalny. 28: 249–258.

External links

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