ErSIDGE — SOrTn-AFETCATSr EOCKS. 



49 



from it. I believe his wide dislocation of the Ceres beds from the clay- 

 slate to be an error into which he has been led by a state of things 

 like that of Ezel's Poort. I have never been able to get direct proof 

 that this is the case here, although I have elsewhere, as shall pre- 

 sently appear. 



On my return to the Eastern Province, I thought I saw evidence 

 of the siliceous change of rocks on a much greater scale than I had 

 observed them in JSiamaqualand. I wrote a Paper on the subject, 

 and published it in the local magazine I have quoted above (' Eastern 

 Province Magazine,' vol. ii. p. 187). I hoped it would have led my 

 friends here, from whose sections mine differed considerably, to re- 

 examine their data. A little after, I sent home a Paper which was 

 read at the Geological Society of London (see an abstract of it in the 

 'Geological Society's Journal,' vol. xv. p. 195), in which I explained 

 these views, and predicted that the clay-slate of the west would here- 

 after be found identical with the Upper Silurian of Bain, and the Car- 

 boniferous rocks of the east identical with both, the quartzite being 

 changed rock, sometimes slate itself, sometimes a newer unconfor- 

 mable rock. Of this identity I was enabled to send home strong 

 presumptive proof in the shape of fossils identical with the Upper 

 Silurian of Bain, from the clay-slate on the western shores of Francis 

 Bay. More recently I have obtained the same fossils (pronounced 

 Devonian at home) from various points between the Kromme and 

 Kabeljouw rivers, St. Francis Bay, in the clay-slate, and from Chatty, 

 near Port Elizabeth ; from Naroo, near Uitenhage ; from Blauw 

 Krauts, on the Bezuidenhouts river, on the road to Graaff Eeinet ; 

 and from the northern base of the Coxcomb in the Winterhoek 

 range in the Carboniferous. Still, it might be objected that there 

 may really be a difference between the clay-slate and the Devonian, 

 though Mr. Bain may have mistaken the line of division. If refer- 

 ence be made to the Admiralty chart of St. Francis Bay, it will be 

 seen that the low shores of the bay are crossed by a range of moun- 

 tains of considerable elevation. These mountains, which are quartz- 

 ite, cross the strike at a considerable angle, nearly, in fact, for some 

 distance at a right angle ; so that on the beach and the low hills you 

 may cross near ten miles of slate, perhaps five miles of strike, while 

 six or eight miles inland, on the heights, the corresponding part of 

 the section is all quartzite. The quartzite must, consequently, cross 

 unconformably the slates, and therefore be newer than they. The 

 reasons why they cannot be older, I need not give here, as I have given 

 many of them above. These same quartzite hills are continuous with 

 others of the same lithological character, which are decidedly confor- 

 mable with the Devonian rocks, though they too cross the strike at an 

 angle of 30°. I have not had opportunities for such an examination 

 of the country between this and Cape Town, as to enable me to say 

 positively that there are no beds older than the Devonian ; but I 

 think I have shown satisfactorily that the evidence on which the clay- 

 slate is referred to a much higher antiquity is fallacious. I can safely 

 assert that the Devonian beds of this country are crossed by lofty 



YOL. T. H 



