From the Ocean to the Loreley. About 400 million years ago today’s Middle Rhine area was submerged beneath a great ocean. 325 million years ago, at the dawn of the Carboniferous period, there was a collision of tectonic plates which caused the complete disappearance of that ocean.
A massif was formed made up of different types of rock,depending on the intensity of pressure and heat.
Today the geology of the area is dominated by slate, sandstone – the so-called
‘greywacke’ – and quartzite. The rocks were squeezed together and uplifted.
There is visible evidence of this on many of the valley’s rocky hillsides: at the
Loreley, for example, at Spitznack and near Boppard, too. During the following
ages the mountains were eroded and a flat landscape evolved. About 25
million years ago the Rhine appeared for the first time as a tiny rivulet. The course of today’s river has only developed over the last 2.5 million years. Ice ages brought a harsher climate and tectonic activity led to alternating phases of inactivity and uplift. Large masses of water and debris were washed down from the glaciers of the Alpine region, cutting out the spectacular Rhine gorge. The steep canyons are between 70 and 200 metres above sea level and were formed during the Ice Ages of the past 700 000 years.