This illustration is intended to illustrate what happens with the continental plate shifts with mountain formation. Plutonism creates the conditions in the Alps and elsewhere for gold and many other minerals to reach the surface of the earth. The active zone is shown under the Gotthard massif. The plutonite or the larger, mostly branched version, the batholite, takes hundreds of thousands of years to complete cooling. On the fringes of Plutonite the rock is transformed by the great heat, there are contact metamorphoses instead. So on the fringes, the water present in the rocks becomes volatile - hydrothermal processes take place. The hot water becomes aggressive solutions. These leach out minerals from large rock masses. The solutions increase due to existing cracks, columns and cavities. Near the surface, with decreasing temperature and decreasing pressure, the minerals recrystallize.
The left side of the valley Sumvitg
Click to enlarge With this sketch I try to represent the underground of the left side of the valley of Val Sumvitg. Left to exactly the Val Lavaz is the cooled Pluton, today granite, weathered and open-minded. Then to the far right, the rocks have been greatly altered by contact metamorphism. In the terrain, as shown on the sketch, pegmatite courses, quartz bands and rarely ore bodies can be seen in many places.
