Abstract

Two of the three series of the Cape System, on the southern tip of the continent, have been dated on fossil evidence as having been deposited during the Devonian Period. The lowermost or Table Mountain Series is unfossiliferous; it is followed conformably by the Bokkeveld Series, consisting of shale and sandstone, and this conformably by the Witteberg Series which consists of shale and white quartzite. These series were deposited in a trough that trended east-west, deepened southwards, and had an eastward pitch. The Bokkeveld strata especially show signs of decreasing grade of washing both southwards and eastwards, and it is suggested that this characteristic persists into the lower Witteberg strata but that the upper Witteberg was deposited when conditions were more uniform over the whole trough.

The lower part of the Bokkeveld Series contains fossil evidence proving that the strata were deposited under marine conditions during early Devonian time. The upper two-fifths of the series contains scattered plant remains, as does the lower part of the Witteberg. On rather unsatisfactory grounds these have been taken to indicate deposition during a time- interval extending from the Middle Devonian to the early Carboniferous. Fossil fish found in the upper Witteberg prove that these rocks are of early Carboniferous age..

Previous workers have drawn attention to the similarities of the marine fossils of the lower Bokkeveld of South Africa to the lower Devonian remains of the Falkland Islands and South America; they have an Austral impress in distinction to the Boreal aspect of the remains of the same age in the northern continents.