Editing Rhine (section)

===Alpine orogeny===
[[File:Rhinegrabencross.jpg|thumb|Schematic cross section of the [[Upper Rhine Graben]]]]

The Rhine flows from the [[Alps]] to the [[North Sea#Geological history|North Sea Basin]]. The geography and geology of its present-day watershed has been developing since the [[Alpine orogeny]] began.

In southern Europe, the stage was set in the [[Triassic]] Period of the [[Mesozoic]] Era, with the opening of the [[Tethys Ocean]], between the Eurasian and African [[plate tectonics|tectonic plates]], between about 240&nbsp;[[Before Present|MBP]] and 220&nbsp;MBP (million years before present). The present [[Mediterranean Sea]] descends from this somewhat larger Tethys sea. At about 180&nbsp;MBP, in the [[Jurassic]] Period, the two plates reversed direction and began to compress the Tethys floor, causing it to be subducted under Eurasia and pushing up the edge of the latter plate in the Alpine Orogeny of the [[Oligocene]] and [[Miocene]] Periods. Several microplates were caught in the squeeze and rotated or were pushed laterally, generating the individual features of Mediterranean geography: Iberia pushed up the [[Pyrenees]]; [[Italy]], the Alps, and [[Anatolia]], moving west, the mountains of [[Greece]] and the islands. The compression and orogeny continue today, as shown by the ongoing raising of the mountains a small amount each year and the active volcanoes.

In northern Europe, the North Sea Basin had formed during the Triassic and Jurassic periods and continued to be a sediment receiving basin since. In between the zone of Alpine orogeny and North Sea Basin subsidence, highlands resulting from an earlier orogeny ([[Variscan orogeny|Variscan]]) remained, such as the [[Ardennes]], [[Eifel]] and [[Vosges]].

From the [[Eocene]] onward, the ongoing Alpine orogeny caused a north–south rift system to develop in this zone. The main elements of this rift are the [[Upper Rhine Graben]], in southwest Germany and eastern France and the Lower Rhine Embayment, in northwest Germany and the southeastern [[Netherlands]]. By the time of the Miocene, a river system had developed in the [[Upper Rhine Graben]], that continued northward and is considered the first Rhine river. At that time, it did not yet carry discharge from the Alps; instead, the watersheds of the [[Rhone]] and [[Danube]] drained the northern flanks of the Alps.