Råstofkortlægning. Erfaringer fra en forsøgskortlægning ved Ålborg

Abstract

The Geological Survey of Denmark (DGU) may be placed in a central position in future mapping of geological raw materials. For this reason, a pilot mapping project was carried out during October 1975. This paper is a presentation of a possible procedure, based on experience from the pilot project. It is suggested that resource planning is accomplished in six steps, the first of which is a synthesis of known data, presented as maps showing potential resources. The mapping method is described in detail and illustrated by examples from the pilot project. Three categories of maps are considered: A - Maps from previous investigations showing basic geological data (A 1) and special features, e.g. the Pre-Pleistocene surface (A 2), geophysical interpretations (A 3), groundwater chemistry (A 4) and contour lines of groundwater level (A 5) etc. B - Maps representing compilations and interpretations which are indispensable for the preparation of the resource maps, e.g. maps of surface lithology (B 1), quarries, pits and borings except waterwells (B 2), terrain morphology (B 3), terrain analysis (B 4) and maps showing the known distribution of raw materials (B 5a: Clay, B 5b: Sand and gravel, B Se: Limestone, etc.) C - Resource maps giving the concluding geological evaluation of all areas. The preliminary maps indicate the location of potential resources. It is not intended to give any evaluation of their quality or utility, since the criteria on which such judgments have to be based are highly variable depending on production techniques, market price etc. Finally, an outline is presented showing how detailed plans for production and supply may be developed by subsequent planning and additional investigations.