Meddelelser fra Vannboringsarkivet nr. 2. Vannboringer utført i traktene omkring Mjøsa og Randsfjorden 1950-52.

Abstract

A brief report is given on some water-borings carried out at Mjøsa and northern Randsfjord during the last few years. The rocks in the districts in question consist of Precambrian granite and gneiss. Eocambrian sandstone (sparagmite), quartzite and limestone and Permian rhombporphyry and sandstone in Brumunddal. Drillings are carried out in the different types of rocks. The stratigraphic succession of the rocks, their properties and water-yielding capacities are given. A geological map of the central district of Mjøsa, and the borings there are shown. As a conclusion one may say that the soft shales yield little or no water, while the brittle quartzites, sandstones and limestones of sufficient thickness are good aquifers. The Eocambrian rocks (\"the sparagmites\") and the Cambro-silurian have developed a regular fracture system due to the Caledonian earth-movements, and their water yielding capacities are therefore nearly uniform. The fractures in the Precambrian, however, are less regular and the depths of the drillings in these rocks and the water yield from them are more variable.