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.
Sveconorwegian orogeny orogeny propagated eastward. There are differing views on the nature of the orogeny. One view, known as the "classical", postulates that a continent–continent collision, possibly with Amazonia, was responsible for giving the orogenic belts its current characteristics. An alternative view postulated in 2013 claims such collision did likely not occur as the characteristics of the orogen would be explained solely as the result of subduction and accretion of smaller terranes. These different views have implications for the configuration of the ancient supercontinent Rodinia. The southern part of what would eventually become the Western Gneiss Region of Norway formed migmatites and