The Volcanoes of Griqualand East. Ill 



of fossil ferns which could not have floated far before they becani& 

 embedded, but the softer beds are separated at repeated intervals by- 

 great beds of coarse sandstone. This sandstone is what Mr. Dunn 

 calls ** glittering sandstone," and seen in the strong sunlight it has- 

 the appearance of having every grain specially faceted to catch and 

 reflect the light. The grains consist of clear fresh quartz, such as- 

 one gets in granite or felsite, often as big as peas, and sometimes, 

 showing unworn crystal faces ; besides quartz there is a very large 

 amount of felspar, now weathered and turned into kaolin, but many 

 grains still retaining sharp crystal faces, and in addition large mica 

 flakes are frequently found. These sandstones must have been 

 derived from a granite or quartz -felsite, and not a dyke of such 

 material is present in the Karroo, and again, the grains of quartz, 

 felspar, and mica are too fresh to have travelled all the way from the 

 old northern land. The Karroo land in Jurassic times then could 

 not have afforded the material for the Stormberg Beds. Whence, 

 then, was the material derived ? The only answer is, from a land- 

 mass to the south which has since sunk beneath the sea. From 

 other considerations derived from the study of the western part of 

 the Colony we had already begun to believe that an old land-mass, 

 had once existed along our southern shores, but we had no very safe 

 arguments to go upon ; but taking all the evidence now it is highly 

 probable that in Cretaceous times there existed a large archipelago 

 of islands, if not a connected land-mass, in the neighbourhood of 

 our present southern shores ; and that it was in the sea, enclosed 

 between this southern land and the old northern land that the sedi- 

 ments from the Table Mountain Sandstone upwards were deposited,. 

 It is very probable that Madagascar and the Seychelles are remnants 

 of this southern continent, but off our present shores the sea-bottom 

 shows no trace of the presence of a submerged land. 



Let us now see how all this bears on our volcanoes. First of all 

 there was a shore-line running roughly N.E. Sediments were 

 deposited off the shore of this continent in a band parallel to it, that 

 is, also N.E. A w^atershed afterwards was formed in these new" 

 sediments running N.E. A line of volcanoes broke out, that line 

 running N.E., and the shore of our present land was cut ofl" in a 

 N.E. direction. I think few people would deny that all these 

 phenomena had some common cause which gave the dominant 

 trend to all. 



My explanation is as follows : — The sediments from the Dwyka 

 Conglomerate upwards were deposited on an inland sea," the centre 



* It shoukl be noted that this is not the same inland sea that Mr. Dunn postu- 

 lated in his paper to this Society [Trans., vol. xi., pt. 1, pi. i.), since where he 



