|
Forkortet: The remarkable development in Norway of several chemico-technical branches of industry during the last twenty to thirty years has immensely increased the use of limestone. The object of the present paper is to contribute to our knowledge of the supply of native limestone. It is confined, however, to the occurrence of limestone in the "Oslo Field", indicated on the map, Fig.1, by darker tone. The occurrences in the Oslo Field are all of Ordovician or Silurian Age. As in the case of the palaeozoic sediments, here the lime- stone layers are never horizontal, but, from folding or other causes, are in- clined. The strike in the folded, northern districts is NE-SW to E-W. Descriptions of the several occurrences arranged according to districts menti- oned om pp.12,13 are to be found on pp. 13-63. As the most important occurrences of Ordovician limestone may be mentioned: The Enkrinit-limestone in the Langesund-Skien Valley district, the Gastropod-limestone in the Hadeland, the Mjøs-limestone in the "Mjøsdistrict" of Silurian: the Borealis-Pentamerus- limestone in the Hadeland, the Pentamerus-limestone in the Drammen Valley dis- trict, Bærum-Asker-Lier, Ringerike and the Mjøsdistrict, the Wenlock-limestone in the Langesund-Skien Valley district, the limestone of etage 9 d. |
