Page:South African Geology - Schwarz - 1912.djvu/162

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152
SOUTH AFRICAN GEOLOGY

berley and Calvinia a number of remains of a little reptile called Mesosaurus, while Glossopteris occurs sparingly. The Lepidodendron flora is represented by a few rare Sigillaria and Lepidodendron stems. In German Narnaqualand the shell Eurydesma and a Conularia have been described from this horizon, which, if authenticated, will prove that there was a connection with the sea on this side.

An interesting area of Dwyka Conglomerate occurs south of the great Worcester-Swellendam fault, which is quite typical and which shows that the Dwyka Conglomerate was continuous once over the mountains which separate this area from the Karroo; that is to say, the southern border of the lake was to the south of the present shore line. Little patches of the Dwyka Conglomerate occur in the folds in the mountains themselves. It was once held that the Karroo Beds, with the Dwyka Conglomerate at the base, were laid down in a lake the southern borders of which were where the present coast ranges lie; but as the Karroo Beds occur to the south of the mountains it is evident that the mountains were folded up after the Karroo sediments were all deposited, and that the Dwyka Shales exposed on the flanks of the mountains are the beds deposited in the deeper central portion of the Karroo lake exposed by folding. This disposes of the theory that the carbonaceous beds of the Upper Dwyka Shales may, in the deeper portions of the Karroo, become actually coal-bearing, a theory which has been urged and on which thousands of pounds have been spent in boring for this hypothetical coal. The underlying idea, however, of this theory is not geological at all; it arose from the belief that God made all parts of the earth