182 Mr. Bain on the Geology of Southern Africa. 



No. 1, from the top of Table Mountain to that of the high mountain at Michell's 

 Pass, will give some faint idea of the magnitude of this denudation ; for there 

 cannot be the smallest doubt that those two mountains were at one time connected. 



It appears to me that no agent with which we are acquainted could have effected 

 this immense degradation and the complete removal of the fragments but the tides 

 and marine currents, as the mountains slowly emerged from the bosom of the 

 primeval ocean, and that too probably before the rocks had attained their present 

 tenacity of consistence. Not a fragment of this sandstone is now to be found on 

 the flats or plains at any distance from the mountains, except here and there small 

 portions in situ, resting unconformably on the clayslate, just sufficient to attest 

 that the whole had at one time been continuous. 



This formation extends from Donkin's Bay, on the west coast, to Cape St. 

 Francis, on the east, including all the high mountains of the Cape peninsula and 

 Hottentots Holland ; and, from the extensive excavations I have made in it, I 

 think I can safely say that it contains no fossils. The only minerals I have 

 discovered are iron-pyrites and some oxides of iron of no value. 



Leaving the quartzose sandstone, I shall proceed briefly to describe the South 

 African 



Upper Silurian Rocks*, 



where the first signs of primeval life begin to appear. Many specimens of the 

 fossils of this series have at various times found their way to Europe ; but, as far 

 as I am aware, no attempt has ever been made to show their position among the 

 South African formations, which I shall now endeavour to do, however imperfectly. 



This Upper Silurian formation can be well traced in the Warm and Cold 

 Bokkevelden, where it rests conformably on the above-described sandstones, and 

 where its lowest strata contrast wonderfully with the rough gritty sandstone beds 

 on which they repose. They consist principally of soft micaceous deposits, of 

 various colours, abounding in small Trilobites, Crinoids, and Brachiopods, the 

 fossils being frequently enclosed in small rounded nodules. Higher up in the 

 series, the rocks are composed of a greyish sandstone containing numerous casts of 

 Spirifers, which, from a fancied resemblance to the Butterfly, the Boers call Schoe- 

 lappers. 



Next are found compact, blue, argillaceous schists, easily disintegrating when 

 exposed to the sun, and abounding in Trilobites of a larger size, Conularia, 

 Brachiopods, and other Mollusks. This subdivision is overlaid by a deposit 

 resembhng the lowest micaceous beds, but containing a much greater variety of 

 Mollusks, as well as many specimens of the heads, bodies, and tails of a large 



* See previous Note at p. 181. 



