![Sample our Geography journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5937/TOC-Subject-Sample-2021-Geography.jpg"})
Abstract
Classification of granitic rocks on rock density determinations is applied to a granitic complex on Bornholm. It is shown that the system presented by Kopf (1966, 1967) cannot be applied generally. It is concluded that the variations in rock densities mainly depend on the contents of mafic minerals, and as the nomenclature of granitic rocks mainly are based on the salic minerals, the densities cannot be used to classify the granitic rocks. It is shown that density determinations can be used sucessfully in mapping of granitic complexes looking homogeneous. Another physical property of rocks is the magnetic susceptibility. It has been proposed by Kopf (1966, 1967) that there should exist a correlation between increasing susceptibility and increasing degree of chloritization of the mafic minerals in the rocks (hornblende and biotite). It is shown that such correlation does not exist generally.