From Monte Brè to Monte Boglia until Alpe Bolla the subsoil consists of siliceous limestones and dolomites from the Lower Jura. In the area of the Denti della Vecchia an older layar is emerging. In the area of the Denti della Vecchia and the hut of Pairolo the layars are even more ancient. The mountain of Gazzirola consists of gneiss which represents the oldest rock surface in Ticino.
The rocks belong to the Malcantone prevarisico base of the Southern Alps. It is crystalline rock composed mainly of quartz, feldspar, mica and dark minerals. During the orogenic events have formed the huge cracks that allowed the ascent of fluids rich in minerals, silver, gold and iron.
The territory of the municipality of Paradiso is geologically interesting for its crystalline basement (gneiss, filloniti-zone of the Val Colla) and, to a greater extent, by Triassic sedimentary rocks. Outcrops can be observed directly on the slopes of Monte San Salvatore and along the valleys. Of particular interest is the anticlinal structure of the banks of the San Salvatore Dolomite which, together with the fracturing and glacial modeling, have led to the current situation: a morphological example for the entire region.
Remember that the museum of Monte San Salvatore exhibits a permanent corner that houses a collection of geological material such as rocks, minerals and fossils for educational purposes and aims at presenting the evolution of the territory, with a particular interest in the region of San Salvatore.
Important Quaternary deposits can be found in the plain overlooking the gulf of Lugano. They are represented by glacial deposits, deltaic, marsh, and alluvial deposits from the surface with clear traces of human rework.
The lithostratigraphy of Monte San Giorgio includes various rock units that are divided into two distinct groups, the hoof or the crystalline basement and the sedimentary overlap. Moving to the summit of mountain the latest rock formations can be found.
The rock of Monte Generoso is made up of flint limestone, a sedimentary rock that originated on the sea floor 200 million years ago. The mountain is an end point of the glacial expansions and rises from the plains and the mountains. These aspects make the mountain a natural museum of karst and rich in anthropological findings. Click here for more information on caves and karst of Monte Generoso.