The formation of the alpine lakes

The lush green forest around the alpine lake Lago di Saoseo in Val da Camp of Graubünden in Switzerland is spellbound in a mystical light backlit by the sun. In summer, the early morning light peeks across the mountain ridge and warms up the ice cold air in the high mountain valley. The humidity rises as mist and fog for a fleeting moment, creating this enchanting atmosphere.
Tarns are mostly formed in postglacial landforms as scooped-out bases of cirques that were carved by glaciers during the last ice age. Some lakes, like Lago di Saoseo, formed behind rock slides barriers. In either form, these small and hidden alpine lakes are among the most beautiful landforms in the European Alps and are true gems.
The mountain uplift processes of the European Alps are a complex geological phenomena that has continued for the past 250 million years. The ancient Tethys Ocean was more than 600 miles (1000 km) wide and was located in today’s area of the Mediterranean Sea. Due to active subduction on both sides of the ocean Tethys shortened to a width below 60 miles (100 km) including its deep trenches. This finally caused the continental collision of Africa and Europe. Consequently, a mountain range developed out of uplifted ocean sediments, volcanic ocean crust piled up onto land, called ophiolithes, and continental granite that partly metamorphosed into gneiss. All of this organized into faulted structures called nappes. The limestone sediments of the Tethys Ocean including coral reefs are now located at an altitude of 8200 ft (2500 m). The rocks of the central alpine crest often contain greenstones. These highly metamorphic rocks originate from the volcanic basalt sea-floor of the Tethys Ocean. They were uplifted to an elevation of 13000 ft (4000 m) during the collision process of the European plate with the African plate. Such geologic processes are rare. Hence they produce rare mineral compositions. Tourmaline and emerald are among the typical minerals associated with that type of metamorphic rock.