Fen Complex, Nome, Telemark, Norway

Famous for it's rare volcanic/meta-volcanic rocks:

Carbonatites; søvite (coarse-grained calcite carbonatite), rødberg (altered carbonatite with hematite stained granular calcite, dolomite and sometimes ankerite), rauhaugite (dolomite carbonatite), ringite (coars-grained carbonatite containing aegirine and alkali-feldspar).
Lamprophyres; damkjernite (melanocratic nepheline lamprophyre).
Ijolites; melteigite (melanocratic nepheline ijolite), hollaite (calcite-melteigite, consisting of pyroxene (55%), calcite and nepheline).
Other rocks; fenite (metasomatic rock composed of alkali feldspare, sodic pyroxene and/or alkali amphibole, sometimes monomineralic alkali feldspar rock), vibetoite (pyroxenite containing aboundant Ti-augite and hornblende with biotite, primary calcite, and occasional albite and nepheline).

Many of the rocks were first described by W. C. Brøgger in 1921.
Most of the complex are now protected because of it's value to science, and collecting is prohibited!

References:
- Brøgger, W.C. (1921) Die Eruptivgesteine des Kristianiagebietes. IV. Das Fengebiet in Telemark, Norwegen. Norske Skrifter udgit av Videnskabsselskabet i Kristiania. I. Math. Nat. Klasse. No.9, p. 1-408.

- Andersen, T. (1984) Secondary processes in carbonatites: petrology of "rødberg" (hematite-calcite-dolomite carbonatite) in the Fen central complex, Telemark (south Norway). Lithos: 17: 227-245.

- Andersen, T. (1986) Compositional variation of some rare earth minerals from the Fen complex (Telemark, SE Norway): implications for the mobility of rare earths in a carbonatite system. Mineralogical Magazine: 50: 503-509.

- Andersen, T. (1988) Evolution of peralkaline calcite carbonatite magmas. Experimentally determined trace and minor element partitioning in the Fen complex, southeast Norway. Lithos: 22: 99-112.