Geology

From a geological aspect, Mount Pilatus is the northernmost branch of the Alps. The geological edge of the Alps stretches right through Lake Lucerne. Along this border run the sedimentary layers which traverse the whole of Switzerland and, with the lakes in the Alpine foothills, create some of Switzerland's most stunning scenery.
No mountain in the long northern arc of the Alpine foothills shows such a marked upwards thrust as Mount Pilatus on Lake Lucerne. Its rock consists of cretaceous sediment and Tertiary deposits.
The calcerous rocks of Mount Pilatus were formed in the sea which stretched between the Aare and the Gotthard massif. Mussel, oyster, ammonite, echinite and sea snail fossils today discovered in the Mount Pilatus rock provide valuable documentation and evidence of when and where the fairly dense cliffs and fine slate layers of the mountain were created.

Image: Eastern flank of Mount Pilatus

Image: Eastern flank of Mount Pilatus

Vaults and dips are additional evidence of the shifting of the earth's crust which thrust up the one-time horizontal sea bed into these mighty folds. Such displaced layers are called plates. The entire Alpine chain from the Säntis to Lake Thun was thrust over the Aare massif into the full Molasse Sea and covered part of Switzerland. These rock folds were then known as the«Helvetic Plate». With its offshoots (Bürgenstock, Rigihochfluhkette), Mount Pilatus is part of the front of this plate.

On the eastern flank of Mount Pilatus, towards Lucerne, the profile of Lucerne's "own" mountain reveals five folds (see illustration), all of which incline to the north.

The geological development of the rock on Mount Pilatus displays the characteristic features of erosion and weathering which make the mountain the landmark of Central Switzerland.