Paratethys
Encyclopedia
| Paleogeography of the Tethys ocean Tethys Ocean The Tethys Ocean was an ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean.-Modern theory:... in the Rupelian Rupelian The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene epoch/series. It spans the time between and . It is preceded by the Priabonian stage and is followed by the Chattian stage.... age (33,9-28,4 million years ago). Black lines indicate present day coastlines. |
The Paratethys ocean, Paratethys sea or just Paratethys was a large shallow sea that stretched from the region north of the Alps
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
over Central Europe
Central Europe
Central Europe or alternatively Middle Europe is a region of the European continent lying between the variously defined areas of Eastern and Western Europe...
to the Aral Sea
Aral Sea
The Aral Sea was a lake that lay between Kazakhstan in the north and Karakalpakstan, an autonomous region of Uzbekistan, in the south...
in western Asia. The sea was formed during the Oxfordian epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...
as an extension of the rift that formed the Central Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
and was isolated during the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
epoch (after 34 million years ago). It was separated from the Tethys Ocean
Tethys Ocean
The Tethys Ocean was an ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean.-Modern theory:...
to the south by the formation of the Alps
Alpine orogeny
The Alpine orogeny is an orogenic phase in the Late Mesozoic and Tertiary that formed the mountain ranges of the Alpide belt...
, Carpathians, Dinarides, Taurus
Taurus Mountains
Taurus Mountains are a mountain complex in southern Turkey, dividing the Mediterranean coastal region of southern Turkey from the central Anatolian Plateau. The system extends along a curve from Lake Eğirdir in the west to the upper reaches of the Euphrates and Tigris rivers in the east...
and Elburz mountains. During its long existence the Paratethys was at times reconnected with the Tethys or its successors, the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
or Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
. From the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
epoch onward (after 5 million years ago), the Paratethys became progressively shallower. Today's Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...
, Caspian Sea
Caspian Sea
The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...
, and Aral Sea are remnants of the Paratethys Sea.
Name and research
The name Paratethys was first used by V.D. Laskarev in 1924. Laskarev's definition included only fossilFossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s and sedimentary strata
Stratum
In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...
from the sea of the Neogene
Neogene
The Neogene is a geologic period and system in the International Commission on Stratigraphy Geologic Timescale starting 23.03 ± 0.05 million years ago and ending 2.588 million years ago...
system. This definition was later adjusted to also include the Oligocene series
Series (stratigraphy)
Series are subdivisions of rock layers made based on the age of the rock and corresponding to the dating system unit called an epoch, both being formally defined international conventions of the geological timescale. A series is therefore a sequence of rock depositions defining a...
. The existence of a separated water body in these periods was deduced from fossil fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...
(most importantly molluscs, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
and ostracods). In periods in which the Paratethys or parts of it were separated from each other or from other oceans, a separate fauna developed which is found in sedimentary deposits. In this way the paleogeographical development of the Paratethys can be studied.
Sedimentary strata from the Paratethys are difficult to correlate with those from other oceans or seas because at times it was totally separated from them. Stratigraphers
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
of the Paratethys therefore have their own sets of stratigraphic stages which are still used as alternatives for the official geologic timescale of the ICS
International Commission on Stratigraphy
The International Commission on Stratigraphy , sometimes referred to by the unofficial "International Stratigraphic Commission" is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphy, geological, and geochronological matters on a global...
.
Paleogeographical development
The Paratethys spread over a large area in Central Europe and western Asia. In the west it included in some stages the Molasse BasinMolasse basin
The Molasse basin is a foreland basin north of the Alps, that formed during the Oligocene and Miocene epochs. The basin formed due to the flexure of the European plate under the weight of the orogenic wedge of the Alps that was forming to the south....
north of the Alps; further east the Vienna Basin
Vienna Basin
The Vienna Basin is a sedimentary basin between the Alps and the Carpathian Mountains...
and the Pannonian Basin
Pannonian Basin
The Pannonian Basin or Carpathian Basin is a large basin in East-Central Europe.The geomorphological term Pannonian Plain is more widely used for roughly the same region though with a somewhat different sense - meaning only the lowlands, the plain that remained when the Pliocene Pannonian Sea dried...
; the basin of the current Black Sea; and from there it spread eastward until the current position of the Aral Sea.
This part of Eurasia was during the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
and Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
periods covered by shallow seas, that formed the northern margins of the Tethys Ocean. This ocean formed between Laurasia
Laurasia
In paleogeography, Laurasia was the northernmost of two supercontinents that formed part of the Pangaea supercontinent from approximately...
(Eurasia and North America) and Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
(Africa, India, Antarctica, Australia and South America) when the supercontinent
Supercontinent
In geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...
Pangea broke up during the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
(200 million years ago).
The boundary between the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
and Oligocene epochs was characterized by a big drop of the global (eustatic) sea level and a sudden steep cooling of global climates. At the same time the Alpine orogeny
Alpine orogeny
The Alpine orogeny is an orogenic phase in the Late Mesozoic and Tertiary that formed the mountain ranges of the Alpide belt...
, a tectonic phase by which the Alps, Carpathians, Dinarides, Taurus, Elburz and many other mountain chains along the southern rim of Eurasia were formed. The combination of a drop in sea level and tectonic uplift resulted in a large regression
Marine regression
Marine regression is a geological process occurring when areas of submerged seafloor are exposed above the sea level. The opposite event, marine transgression, occurs when flooding from the sea covers previously exposed land....
of the sea and a barrier was formed between the Tethys and Paratethys domains. Connections with the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
(the Turgai Sea
Turgai Sea
The Turgai Sea or Turgai Strait, also known as the West Siberian Sea, was a large shallow body of salt water of the Mesozoic and Cenozoic Eras...
), the North Sea Basin and Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
(in the form of a strait
Strait
A strait or straits is a narrow, typically navigable channel of water that connects two larger, navigable bodies of water. It most commonly refers to a channel of water that lies between two land masses, but it may also refer to a navigable channel through a body of water that is otherwise not...
north of the Carpatians) also closed in the Early Oligocene. However, it is possible connections with the Rhônegraben (and the Mediterranean) and the Hessen Strait (that connected the Molasse Basin with the North Sea Basin) still kept open.
The Early Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
(around 20 million years ago) saw a phase of marine transgression. During this period the Paratethys was well connected with the Mediterranean again. This trend was reversed halfway in the Miocene, and parts of the Paratethys were often separated from each other. When the Mediterranean fell dry during the Messinian salinity crisis
Messinian salinity crisis
The Messinian Salinity Crisis, also referred to as the Messinian Event, and in its latest stage as the Lago Mare event, was a geological event during which the Mediterranean Sea went into a cycle of partly or nearly complete desiccation throughout the latter part of the Messinian age of the Miocene...
(about 6 million years ago) there were phases when Paratethys water flowed into the dry Mediterranean basins. During the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
epoch (5,33 to 2,58 million years ago) the former Paratethys was divided in a couple of inland seas that were at times completely separated from each other. An example was the Pannonian Sea
Pannonian Sea
The Pannonian Sea was a shallow ancient sea located in the area today known as the Pannonian Plain in Central Europe. The Pannonian Sea existed during the Miocene and Pliocene epochs, when three to four kilometres of marine sediments were deposited in the Pannonian Basin.-History:The Pannonian Sea...
, a brackish
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
sea in the Pannonian Basin
Pannonian Basin
The Pannonian Basin or Carpathian Basin is a large basin in East-Central Europe.The geomorphological term Pannonian Plain is more widely used for roughly the same region though with a somewhat different sense - meaning only the lowlands, the plain that remained when the Pliocene Pannonian Sea dried...
. Many of these would disappear before the start of the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
. At present, only the Black Sea, Caspian Sea and Aral Sea remain of what was once a vast inland sea.
See also
- Tethys OceanTethys OceanThe Tethys Ocean was an ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean.-Modern theory:...
- Caspian DepressionCaspian DepressionCaspian Depression or Pricaspian/Peri-Caspian Depression/Lowland is a low-lying flatland region encompassing the northern part of the Caspian Sea, the largest enclosed body of water on Earth. It is the larger northern part of the wider Aral-Caspian Depression around the Aral and Caspian seas.The...
- Messinian salinity crisisMessinian salinity crisisThe Messinian Salinity Crisis, also referred to as the Messinian Event, and in its latest stage as the Lago Mare event, was a geological event during which the Mediterranean Sea went into a cycle of partly or nearly complete desiccation throughout the latter part of the Messinian age of the Miocene...
- Molasse basinMolasse basinThe Molasse basin is a foreland basin north of the Alps, that formed during the Oligocene and Miocene epochs. The basin formed due to the flexure of the European plate under the weight of the orogenic wedge of the Alps that was forming to the south....
- Pannonian SeaPannonian SeaThe Pannonian Sea was a shallow ancient sea located in the area today known as the Pannonian Plain in Central Europe. The Pannonian Sea existed during the Miocene and Pliocene epochs, when three to four kilometres of marine sediments were deposited in the Pannonian Basin.-History:The Pannonian Sea...
- Piemont-Liguria OceanPiemont-Liguria OceanThe Piemont-Liguria basin or the Piemont-Liguria Ocean was a former piece of oceanic crust that is seen as part of the Tethys Ocean...