Mr. Rubidge on the Geology of some parts of South Africa. 313 



the letter referred to. Besides being found in the alluvium there, 

 gold was met with in a quartz-vein in the trap traversing the strati- 

 fied rock, — in other quartz associated with the trap, — and in a mass 

 of limestone enclosed in the trap-dyke ; — but none in the stratified 

 rock itself (which belongs to the Dicynodon or Karoo Series). 



Mr. Ruliidge next alluded to the fossil plants which he there found 

 in the strata ; some of these he referred with doubt to Calamites. Six 

 years ago also the author found numerous vegetable remains (some of 

 which were possibly referable to Lepidodendron) at Jackall's Kop, on 

 the eastern side of the Stormberg Range, in the same formation as 

 that of the Drakensberg and Smithfield ; and Calamite-like plants in 

 the western part of the Zuurbergen. The author remarked that the 

 plant-remains above referred to much resembled those collected by 

 Mr. Bain at the Ecca Heights in rocks of the Karoo Series. Mr. 

 Rubidge had also found bones of the Dicynodon near the Caledon 

 River and at Halse's farm six miles from Smithfield. 



From various observations by himself and others, the author had 

 been enabled to recognize the existence of the Dicynodon or Karoo 

 rocks in the Drakensberg, at Harriesmith, at Winburg, and even at 

 Megaliesberg : and Dr. Sutherland has lately described the same 

 rocks in Natal, where they are rich in coal. 



The amygdaloid rock which supplies the agate-gravel of the Orange, 

 Caledon, Kroai, and Vaal Rivers appears to exist in the " Mont des 

 Sources " in the Drakensberg, as an unworn specimen was found in 

 the Eland River (a tributary of the Vaal), not more than twelve 

 miles from its source. 



Lastly, Mr. Rubidge supplied some remarks on the geology of the 

 copper district of Namaqualand and bordering countries. Granitic 

 rocks of several varieties occur, together with gneiss, mica-schist, 

 and talc-schist. The gneiss strikes 5° to 20° S. of W., and dips 

 alternately N. and S. ; one dip continuing for many miles. On the 

 hills the gneiss and schists are covered by horizontal sandstones, 

 which appear to be the same as the sandstone of Table Mountain, 

 and continuous with it. 



The copper is found in fissures of the gneiss, where it is locally 

 disturbed in its dip, the strike remaining unaltered ; that is, along 

 anticlinal and synclinal folds or axes ; also in fissures extending 

 nearly in the direction of the magnetic meridian, and in crevices 

 between masses of rock, with no veinstone or gangue : the oxides 

 and silicates often appear to I)e infiltered into the rock-mass. The 

 ores most common are red and l)lack oxides, green and blue silicates, 

 purple and yellow sulphurets, and a few carbonates. Granitic rocks 

 are often found in the axes above referred to. 



2. "On the Lowest Sedimentary Rocks of the South of Scotland." 

 By Prof. Harkness, F.G.S. 



The author first described in detail the indications of the axis of 

 the Silurian rocks of Dumfriesshire. It is well seen on the Esk River 

 and the Rennel Burn running into the Esk, — on the Dryfe water a 

 little above Borland Bridge, — in the Shaw Burn, and in the upper 

 part of Auchenrodden Burn in Applegarth parish. Here it is inter-. 



Phil. Mag. S. 4. Vol. 11. No. 72. April 1856. Y 



