| Reference Type | Journal (article/letter/editorial) |
|---|
| Title | Boratmineralet ludwigitt i høymetamorf marmor i Vesterålen |
|---|
| Journal | STEIN. Nordisk magasin for populær geologi |
|---|
| Authors | Bøe, Per | Author |
|---|
| Year | 1997 | Volume | 24 |
|---|
| Page(s) | 130-136 | Issue | 3 |
|---|
| Publisher | Norske Amatørgeologers Sammenslutning |
|---|
| Download URL | http://www.nags.net/Stein/1997/1997-3_Boe.pdf |
|---|
| Mindat Ref. ID | 695982 | Long-form Identifier | mindat:1:5:695982:5 |
|---|
|
| GUID | 36860a33-56b6-4d4e-a91b-0d41c5b72c01 |
|---|
| Full Reference | Bøe, Per (1997) Boratmineralet ludwigitt i høymetamorf marmor i Vesterålen, in Kongsberg Mineralsymposium 1997. STEIN. Nordisk magasin for populær geologi, 24 (3) 130-136 |
|---|
| Plain Text | Bøe, Per (1997) Boratmineralet ludwigitt i høymetamorf marmor i Vesterålen, in Kongsberg Mineralsymposium 1997. STEIN. Nordisk magasin for populær geologi, 24 (3) 130-136 |
|---|
| In | (1997) Kongsberg Mineralsymposium 1997. STEIN. Nordisk magasin for populær geologi Vol. 24 (3) Norske Amatørgeologers Sammenslutning |
|---|
| Abstract/Notes | The Lofoten- Vesterålen region of Northern Norway (lat. 68-69 deg.) is underlain by various plutonic rocks and high grade metamorphic rocks ranging up to granulite facies. Mangerite is a dominating plutonic rock, whereas most gneisses and migmatites have a supracrustal origin. Interbedded in both plutonic rocks and gneisses are a number of calcite- and dolomite marbles, all of them high grade metamolphosed. The size of the individual marbles are up to 2-3 km. The mineral assemblages includes forsterite (often more than 95% Fo), yellow and green spinel (rich in the hercynite component) , clinohumite, chondrodite, magnesioferrite, wollastonite, magnetite and ilmenite. The forsterite is more or less selpentinized. On the promontory to the north of the small settlement of Mehus (locality 7) a calcite marble crops out, with an evident continuation to the south underneath cover in the Mehus farm area. Here, boulders of calcite marble have been found with mineral paragenesis different from other marbles in the region. Among the minerals are the first recorded occurrence in Norway of the boron mineral ludwigite showing up as black needles up to 3 em long, set in white marble matrix. The following microminerals have been detected: Clinohumite as minute grains; perovskite as idiomorphhic cubes, size 0,2 mm; plates of brucite, size 1 mm; clinochlor. yellow spinel 1 to 2 mm, forsterite with an incipient serpentination and diopside. In addition a single boulder weighting 22 kg of imperfect scapolite crystals have been found. It appears that the exposed northern part of the Mehus marble do not contain this interesting mineral assemblages. In some way the whole marble therefor seems to exhibit a crude zonation, the exact nature of this has to await future examination. |
|---|
These are possibly similar items as determined by title/reference text matching only.
