| Full Reference | Andersen, Frode, Berge, Svein A. (1994) Himberg pukkverk, Ramnes, Vestfold, in Tema: En mineralog runder 50. STEIN. Nordisk magasin for populær geologi, 21 (2) 96-102 |
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| Plain Text | Andersen, Frode, Berge, Svein A. (1994) Himberg pukkverk, Ramnes, Vestfold, in Tema: En mineralog runder 50. STEIN. Nordisk magasin for populær geologi, 21 (2) 96-102 |
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| Abstract/Notes | Himberg stone quarry, beeing mined mainly for road metal, is located in Ramnes near the town Tønsberg in Vestfold county. The quarry was opened in the early 1950 s, today it is operated by Martin Haraldstad A/S. Annual production of gravel and crushed stone are about 100.000 tons, most of it beeing exported to Denmark and Germany. Geologically the stone quarry lies within the Ramnes cauldron. The cauldron consists of rock types like syenites, monzonites (kjelsåsite and larvikite) and volcanic rocks. The rocks directly outside the cauldron are lavas, most rhomb porphyries. In the Himberg stone quarry the rock type is mainly a kjelsåsites in parts rich in miarolitic cavities with vugs from mm-size up till 10 - 20 cm. The main minerals in the cavities are orthoclase, albite, quartz, epidote, fluorite and actinolite. Other interesting minerals are babingtonite, prehnite and fluorapophyllite, all in well developed crystals. Of particular interest are the three beryllium minerals occasionally found, milarite, bavenite and helvite (very scarce). Milarite was found in developed, colorless to white, longprismatic crystals to 7 x 2 mm, consisting of a hexagonal prism and pinacoid. Pyramid faces are not observed. Bavenite was found as aggregates of white, longprismatic, thin-rabular crystals less than one mm in size. Groups of aggregates may cover areas up to one cm. Besides the minerals already mentioned there are found allanite-(Ce), andradite, biotite, chabazite, chalcopyrite, fluorapatite,goethite, heulandite, calcite, chlorite, laumontite, magnetite, molybdenite, montmorillonite, opal, polymignite, pyrite, sphalerite, stilbite, titanite and zircon, all together 34 mineral species. |
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