Røros. Beskrivelse til kvartærgeologisk landgeneralkart

Abstract

The present map, dealing with the quarternary deposits of Røros, is partly based on existing maps of a larger scale, certain of which have been published. Areas not geologically mapped beforehand were surveyed in the susal manner. The object being the accumulation of material for a general quarternary map. Special missions have supplemented previous inadequate observations. Fig. 1 shows the various areas surveyed by the geologists concerned. Fig. 2 shows the areas of bedrock covered by the map, as well as glacial striae. Bedrock, and its influence on vegetation. The Eo-Cambrian spargamite group extends over the South-Eastern part of the area. It is interspersed with \"windows\" of Archaean rocks. Strata of quartzitic rock alternate with quartz conglomerates and, occasionally, slatey limestone. The chemical composition of the spargamite corresponds roughly to that of a gra- nite. The slowly disintegrating rock makes for a meagre soil, only locally improved improved by the less predominant limestone. The spargamite accounts for a dry and sandy moraine featuring a profusion of erratics. The pre- dominating Archaen rock is a medium of coarse-grained granite yielding, upon erosion, a moraine similar to that of the spargamite, scarcely supporting vegetation.