Editing Geology of the Alps (section)

===Jurassic===
In the early [[Jurassic]] period (180&nbsp;[[annum|Ma]]), a narrow ocean began to form between the northern (North America and Eurasia) and southern (Africa and South America) parts of Pangaea.  The [[oceanic crust]] that was formed in the process is known as the [[Piemont-Liguria Ocean]]. This ocean is generally regarded as a western extension of the [[Tethys Ocean]].  Although it was not really connected to it, a [[peninsula]]r piece of continental crust of the African plate called the [[Adriatic plate]] lay in between the African and European plates and was involved in subdividing the Tethys and early Alps formation.  Sometimes the names ''Alpine Tethys'' or ''Western Tethys Ocean'' are used to describe a number of small oceanic basins that formed southwest of the European plate, to distinguish them from the Neo-Tethys Ocean in the east.  Because the Jurassic was a time with high sealevels, all these oceans were connected by shallow seas. On the continents, shallow sea deposits (limestones) were formed during the entire Mesozoic.

In the late Jurassic the [[microcontinent Iberia]] broke away from the European plate and the [[Valais Ocean]] was formed between the two plates. Both Piemont-Liguria and Valais Oceans were never large oceans such as today's Atlantic Ocean. What they might have been like is the opening below the [[Red Sea]], continuing down through Africa, forming the [[Great Rift Valley (geographical concept)|Great Rift Valley]]. Eventually, a new ocean will cut through east Africa as the rift develops, dividing a large section of land from the main continent.

When at the end of the Jurassic the Adriatic plate began to move toward the European plate, [[oceanic trench]]es formed in the eastern Alps.  In these, deep marine sediments were deposited, such as [[radiolarite]]s and [[lutite]]s.