Fauna and Stratigraphy of the Stormberg Series. 483 



while the Cave Sandstone was being laid down, for in an outlier of 

 Cave Sandstone near by the rock is full of small fragments of shale 

 and sandstone that were blown out from the volcano. 



Very little, or no, work has yet been done upon the area north of 

 the Orange River, but it is probable that the Cave Sandstone there 

 will be but little affected by volcanic flows - - the volcanoes seemingly 

 having come into being progressively from south to north in point 

 of time. 



The work of du Toit in the south and centre of the area has shown 

 that, presumably in connection with the outbreak of volcanic activity, 

 there was a certain amount of faulting and folding which has affected 

 the sediments but not the overlying lava flows. 



In Maclear, the dips of the Cave Sandstone show that folding took 

 place during, and probably also somewhat previous to its deposition 

 and that they had ceased by the time that the area became flooded 

 with lavas. There are local disturbances of both the Red Beds and 

 the Cave Sandstone, but the overlying lavas are undisturbed. A certain 

 amount of subsidence caused the formation, too, of local hollows which 

 were filled with ash. 



At Siberia, in Wodehouse, faulting on a small scale affects the Red 

 Beds and Cave Sandstone, but not the volcanics. In the Barkly East 

 Division the main bed of Cave Sandstone and the ash-bed are affected 

 by small folds, producing domes and basins in the strata, and - - ac- 

 cording to du Toit - - there is clear evidence of a great zone of sub- 

 sidence formed during the eruption of the earlier lavas. A generalised 

 section along the Kraai River shows the Red Beds and the main- 

 body of Cave Sandstone with the ash-bed bent into an asymmetrical 

 undulating trough, while the lavas with the thin intercalated sand- 

 stone beds lie horizontally and undisturbed except in the east. 



It is of interest briefly to consider the probable changes which took 

 place during Stormberg times in the land area from which these 

 sediments were derived. 



That a land mass lay to the south and probably partly to the east 

 of the present area occupied by the Stormberg beds cannot be doubted. 

 How far to the south it lay we cannot say; but the occurrence of a 

 fair thickness of Molteno Beds near Port St. John's indicates the 

 presence of a land-mass to the south of the present continent. Of 

 its petrological characters little can be said. The constituent minerals 

 of the Stormberg sandstones indicate derivation from granitic or 

 granitoid rocks in part. The lithological character of the original 

 rock from which sediments are derived is always, however, a matter 



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