Which types of rocks are found in the Alps?

The Alps are composed of a diverse range of rock types, reflecting a complex geological history of sedimentation, tectonic collision, and mountain building.12

Sedimentary Rocks

Much of the Alps originated from materials deposited in the ancient Tethys Sea during the Mesozoic Era. These deposits were transformed into horizontal layers of:
* Limestone1
* Clay1
* Shale1
* Sandstone1

Metamorphic and Crystalline Rocks

The Alpine orogeny caused intense metamorphism of preexisting rocks. The Alps contain significant amounts of:3
* Crystalline bedrock: Ancient, hard rock that forms the foundation of the mountain range.1
* Regionally metamorphosed rocks: The Alps are a classic example of a mountain belt composed of rocks altered by high pressure and temperature during continent-continent collisions.2
* High-pressure rocks: The range contains specific metamorphic facies, including blueschists and eclogites, as well as rare samples containing coesite, which indicate extreme burial depths.2
* Hercynian rocks: Weathered rocks dating from the Carboniferous and Permian periods are found in the highest masses of the Alps.4

The Italian foothills of the Alps are primarily composed of limestone and other sedimentary rocks.4