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The Timanide Orogen ((ロシア語:Ороген Протоуралид-Тиманид), literally: "Protouralian–Timanide Orogen") is a pre-Uralian orogen that formed in northeastern Baltica during the Neoproterozoic in the Timanide orogeny. The orogen is about 3000 km long. Its extreme points include the southern Urals 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 plust granitoids and few ophiolites. In contrast the southwestern part of the orogen is made up mostly of sedimentary rocks. I and A type granitoids and volcanic rocks are common in the orogen. From the Late Neoproterozoic o the Middle Cambrian the Timanide Orogen was associated to a subduction zone 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 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 of the Timanide Orogen have produced sediments that are now found in the East European Platform, including the Cambrian Sablya Formation near Lake Ladoga. Studies of sediments points that its likely that the erosion of the orogen was beginning in the Cambrian and then became stronger in Ordovician. The first geologists to study the orogen where Wilhelm Ramsay and Tschernyschev who published works in 1899 and 1901 respectively. Hans Reusch compiled the existing knowledge on the orogen in 1900. ==Note== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Timanide Orogen」の詳細全文を読む スポンサード リンク
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