An Interpretation of magnetometric data from the Lichtenburg and Zeerust districts, Western Transvaal

Abstract

A comparison between aeromagnetic and geological data is made in the area bounded by latitude 25°30'S and 26°15'S and longitudes 25°45'E and 26°45'E. Aeromagnetic and ground magnetic data are used to map the dykes, and magnetic, palaeomagnetic and radiometric data are used to determine the relative and actual ages of these dykes. It was' found that several suites of dykes occur within the study area and that the ages of these dykes range from probably pre-Bushveld Complex to probably post-Karoo. A significant proportion of the known dykes appear to be post-Karoo. The major dyke directions correlate with joint directions in the Chuniespoort Group and also with the present-day stress field. Four grabens have been previously identified in the area, and it is shown that there are several other structures which have characteristics in common with these known grabens.