GEOLOGY

Geology

The bedrock of the Trollfjord Geopark forms the westernmost parts of the Norwegian Caledonides, which extends in western Scandinavia from southernmost Norway to the Barents Sea. These rock units are the remains of the Caledonian orogeny, which formed a Himalaya-scale mountain range in Silurian-Devonian times (430-380 million years ago) resulting from the collision between the ancient continents Baltica (Scandinavia) and Laurentia (North America and Greenland). The Trollfjell Geopark displays a variety of features related to glaciations and deglaciation phases, as well as other Quaternary features such as a significant karstic landscape formed in carbonate rocks. The shorelines from the isostatic rebound, the strandflat, the giant sea caves symbolized by the iconic mountain Torghatten and the karstic landscape of Velfjord with its marble caves are features in which the geopark provides unique and outstanding Quaternary sites.

Trollfjell Geopark display a 500 million years geological macro-cycle, from ocean to ocean. The bedrock is composed of rocks that once were formed beneath, in and by an ancient ocean - The Iapetus. They display the architecture of an oceanic crust and the transition to continental, as well as the final closing of this ocean resulting in the Caledonian mountain chain. The present landscape forms the margin of a 'new' ocean, the Atlantic. The rocks that once were formed by the deposition of sand and gravel along the margin of the Iapetus ocean for almost 500 million years ago, are now the bedrock beneath modern beaches and river banks.