Cimmeria

Cimmeria was an ancient continent, or, rather, a string of microcontinents or terranes, that rifted from Gondwana in the Southern Hemisphere and was accreted to Eurasia in the Northern Hemisphere. It consisted of parts of present-day Turkey, Iran, Afghanistan, Pakistan, Tibet, China, Myanmar, Thailand, and Malaysia. Cimmeria rifted from the Gondwanan shores of the Paleo-Tethys Ocean during the Early Permian and as the Neo-Tethys Ocean opened behind it, during the Permian, the Paleo-Tethys closed in front of it. Because the different chunks of Cimmeria drifted northward at different rates, a Meso-Tethys Ocean formed between the different fragments during the Cisuralian. Cimmeria rifted off Gondwana from east to west, from Australia to the eastern Mediterranean. It stretched across several latitudes and spanned a wide range of climatic zones. History of the concept First concepts A "large, ancient Mediterranean Sea" was first proposed by Austrian palaeontologist Melchior Neumayr in 1883. Studying the distribution of Jurassic faunas, he concluded that an equatorial ocean stretching from India to Central America must have separated a large continent in the northern hemisphere from one in the southern hemisphere. Austrian geologist Eduard Suess named this Mesozoic ocean the Tethys, a mythical ocean which separated a mythical continent – Gondwanaland, home of the tongue-shaped flora – from a boreal continent. German geophysicist Alfred Wegener, in contrast, developed a concept of a single, global continent – the supercontinent Pangea – which, in his view, left no room for an equatorial ocean. A wedge-shaped, east-facing Tethys within Pangea was, nevertheless, proposed by Australian geologist Samuel Warren Carey in 1958. This ocean was later identified as a succession of oceans separated by north-migrating terranes or continental blocks, one of which was Cimmeria. Iranian microcontinent In 1974, after extensive field work in the Middle East, Swiss geologist Jovan Stöcklin identified the northern foot of the Alborz Range in northern Iran as the suture which in the Paleozoic was the northern shore of Gondwana and the remains of the Paleo-Tethys Ocean. Stöcklin also noted that an early Mesozoic or late Paleozoic rift separated the Iranian Plate from the Arabian Plate, and that another southern suture must be the remains of the Neo-Tethys Ocean. The opening of this later ocean, Stöcklin realized, must have transformed Iran into a microcontinent.