Presentasjon av geologiske lokaliteter på grensen mellom Nord-Trøndelag og Helgeland.
Torghatten locality 2: answer
The easy answer is that the sea level has been higher than today. Last ice age a huge glacier covered the Scandinavian peninsula, and therefore pressured down the crust. It rebounded when the glacier melted down, and the sea retreated. Such crustal movements is called isostasy(from Greek: ísos “equal”, stásis “standstill”). When Torghatten became ice-free more than 12 800 years ago, a shoreline was formed at the encircled area, and later raised to c. 100 m above current sea level. Today the crust still rises c. 2 mm per year.
Above the red arrow you see angular stones which are rock falls from the mountainside above covering old shore-deposits. Above the black arrow the stones are smaller and more rounded due to wave-erosion. In other words, they mark a former shoreline.