We are talking about the youngest rocks of the Lechtal Alps. You are in the Cretaceous period (90 million years) were formed. During the first rock formation phase, erosion/weathering had already begun and the mountains were removed. Small and large fragments from various source rocks were pressed together and solidified in a disorganised manner. These stones are called the Gosau layer assigned.
If you take a closer look at a representative of the Gosau layer, you may find all the rock types that occur in the Lech Valley in one stone. If the fragments are round, they are called conglomerate; if they are angular, they are breccia. If the components are very small, they are called sandstone.

If the stones of the Gosau layers are polished, they present themselves as decorative ornamental stones. This is why they are used in many buildings (castles and churches) in Tyrol and Bavaria.