Cimmerian Orogeny Cimmerian Orogeny The Cimmerian Orogeny was an orogeny that created mountain ranges that now lie in Central Asia. The orogeny is believed to have begun 200–150 million years ago (much of the Jurassic Period), when the Cimmerian plate collided with the southern coast of Kazakhstania and North and South China, closing the ancient Paleo-Tethys Ocean between them. The plate consisted of what are now known as Turkey, Iran, Tibet and western Southeast Asia. Much of the plate's northern boundary formed mountain ranges that were as high as the present-day Himalayas. The orogeny continued well into the Cretaceous and Early Cenozoic.
Svecofennian orogeny and thick continental crust collapsed under the influence of gravity and spread out. By 1850 millions years ago this collapse had evolved to a dynamic of extensional tectonics. In this extensional milieu short-lived sedimentary basins formed. The Svecobaltic orogeny developed when subduction bought the Fennoscandian Craton into an oblique collision with the Sarmatian Craton. The mentioned sedimentary basins were destroyed by basin inversion 1830 million years ago. This last event of basin inversion was associated with a period of metamorphism in southern Finland that peaked about 1820 million years ago. Two models exist regarding the origin of the Nordic orogeny: