Die sedimentologie van die Davelsteenkoolveld van die Vryheid- Formasie van die Karoo-Supergroep in die oos-Transvaal.

l6 lithofacies types are present which in turn constitute 3 types of lithofacies cycles namely: (i) An upward-fining tilloid cycle which represents the Dwyka Formation and which was deposited during the regression of the Dwyka glaciers. (ii) Upward-coarsening shale-arkose cycles which represent prograding deltaic increments and which are represented in the Lower and Upper Transition members of the Vryheid Formation. (iii) Upward-fining arkose-shale cycles which are of a fluvial origin and build the Lower Sandstone, Coal and Upper Sandstone members. In the Coal member these cycles are capped by coal beds which were deposited in backswamps of meandering river systems. A structure contour map of the base of the C coal bed suggests a dendritic channel system which had a marked influence on all subsequent sedimentation. -from English summary