The Timanide Orogen (, literally: "Protouralian–Timanide Orogen") is a
pre-Uralian orogen
An orogenic belt, orogen, or mobile belt, is a zone of Earth's crust affected by orogeny. An orogenic belt develops when a continental plate crumples and is uplifted to form one or more mountain ranges; this involves a series of geological proc ...
that formed in northeastern
Baltica
Baltica is a paleocontinent that formed in the Paleoproterozoic and now constitutes northwestern Eurasia, or Europe north of the Trans-European Suture Zone and west of the Ural Mountains.
The thick core of Baltica, the East European Craton, i ...
during the
Neoproterozoic
The Neoproterozoic Era is the last of the three geologic eras of the Proterozoic geologic eon, eon, spanning from 1 billion to 538.8 million years ago, and is the last era of the Precambrian "supereon". It is preceded by the Mesoproterozoic era an ...
in the Timanide orogeny. The orogen is about 3000 km long. Its extreme points include the southern
Urals
The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan. in the south and the
Polar Urals, the
Kanin and
Varanger peninsulas in the north. The
Timan Ridge is the
type area of the orogen.
To the west, at the Varanger Peninsula, the north-west oriented Timanide Orogen is truncated by the younger
Scandinavian Caledonide Orogen that has an oblique disposition. The northeastern parts of the orogen are made up of volcanic and sedimentary rocks, granitoids and few
ophiolite
An ophiolite is a section of Earth's oceanic crust and the underlying upper mantle (Earth), upper mantle that has been uplifted and exposed, and often emplaced onto continental crustal rocks.
The Greek word ὄφις, ''ophis'' (''snake'') is ...
s. In contrast the southwestern part of the orogen is made up mostly of
sedimentary rock
Sedimentary rocks are types of rock (geology), rock formed by the cementation (geology), cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or de ...
s.
I and A type granitoid
A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental ...
s and
volcanic rock
Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and me ...
s are common in the orogen.
From the Late Neoproterozoic o the
Middle Cambrian
Middle or The Middle may refer to:
* Centre (geometry), the point equally distant from the outer limits.
Places
* Middle (sheading), a subdivision of the Isle of Man
* Middle Bay (disambiguation)
* Middle Brook (disambiguation)
* Middle Creek (di ...
the Timanide Orogen was associated to a
subduction zone
Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...
that existed to the northeast of it. Most studies interpret subduction as going inward (subducted
plate moving southwest) albeit one suggest the opposite (subducted plate moving to the northeast).
[
In the Cambrian the Timanide Orogen is believed to have developed in a ]continental collision
In geology, continental collision is a phenomenon of plate tectonics that occurs at Convergent boundary, convergent boundaries. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroy ...
context as Baltica and Arctida collided between 528 and 510 million years ago.[ Some researchers do however dissent from this view suggesting there was never such a collision.]
Erosion
Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...
of the Timanide Orogen have produced sediment
Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...
s that are now found in the East European Platform, including the Cambrian Sablino Formation near Lake Ladoga
Lake Ladoga is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, in the vicinity of Saint Petersburg.
It is the largest lake located entirely in Europe, the second largest lake in Russia after Lake ...
. Studies of sediments points that it is likely that the erosion of the orogen was beginning in the Cambrian and then became stronger in Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...
.
The first geologists to study the orogen where Wilhelm Ramsay and Feodosy Tschernyschev who published works in 1899 and 1901 respectively. Hans Reusch compiled the existing knowledge on the orogen in 1900.
Note
References
{{Geology of Fennoscandia
Orogenies of Europe
Barents Sea
Geology of Norway
Geology of Kazakhstan
Geology of European Russia
Geology of Russia
Neoproterozoic orogenies
Neoproterozoic Europe
Ediacaran orogenies
Cambrian orogenies
Cambrian Europe
Ural Mountains