Roadcut along RV 40 (former RV 8). The locality consists of several nepheline syenite pegmatites, usually 10-30 cm thick, often rather irregularly cross-cutting. Nearly 60 different mineral species have been found in the dikes. Because of its complex and scientifically interesting mineralogy, the locality has been protected by law since 1984.
References:- Sæbø, P. (1966a): A short comment on some Norwegian mineral deposits within the igneous rock complex of the Oslo region. Norsk Geologisk Tidsskrift 46, 260-261
- Sæbø, P. (1966b): Contribution to the mineralogy of Norway no.35. The first occurences of the rare mineral barylite, Be2BaSi2O7, in Norway. Norsk Geologisk Tidsskrift 46, 335-348
-Raade, G. & Mladeck, M. H. (1977): Parakeldyshite from Norway. Canadian Mineralogist 15,102-107
- Larsen, A. O. (1988): Helvite group minerals from syenite pegmatites in the Oslo Region, Norway. Contribution to the mineralogy of Norway no 68. Norsk Geologisk Tidsskrift 68: 119-124 [with analysis of genthelvite from Bratthagen 1]
- Engvoldsen, T., Andersen, F., Berge, S. A. & Burvald, I. (1991): Pegmatittmineraler fra Larvik ringkompleks. STEIN 18(1),15-71
-Larsen, A. O., Raade, G. & Sæbø, P. C. (1992): Lorenzenite from the Bratthagen nepheline syenite pegmatites, Lågendalen, Oslo Region, Norway. Norsk Geologisk Tidsskrift, 72, 381-384.
- Larsen, A. O. (2001): Chemical composition of catapleiites from the syenite pegmatites in the Larvik plutonic complex, Norway. Bergverksmuseets Skrift 18, 5-9 [with an analysis of catapleiite from Bratthagen]
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http://home.c2i.net/aolarsen/Pegmatites.htm
47 entries listed. 44 valid minerals.
