IITJBTDGE — SOUTII-AFKICAN ROCKS, 



51 



isolated masses of slate preserved their dip unaltered in the midst of 

 granite which appeared to have a dip in the same direction. Passing 

 north-vrestward towards JSTamaqualand, I saw the slate near Heer- 

 lozement so little altered and so like some of the fossiliferous rocks of 

 the Eastern Province that I much regretted that my engagements did 

 not permit of a closer examination of it. At Olifant's river the rocks, 

 still with the same strike as in Cape Town, viz. nearly magnetic north 

 (north 30° west), had assumed a micaceous andtalcose character, and 

 on the northern bank of the river were much impregnated with iron. 

 Pour or five miles beyond Kokonap I saw the slate for the last time 

 till I met it at the Orange river, and here it abounded in a peculiar 

 form of cyanite which I afterwards found in great abundance in the 

 gneiss and mica-schist of De Kiet, near Hondeklip Bay. Some 

 grassy country intervened between this spot and the next where 

 rocks were visible. These were felspathic in great variety. I could 

 not get a satisfactory observation of their dip for some days' journey, 

 perhaps owing to the little experience I had then of rocks of this 

 class. There are few things I have more to regret in the way of lost 

 opportunities than the want of a careful examination in detail of the 

 country within ten miles' radius of the lowermost ford of the Olifant's 

 river. It would include a section from the clay-slate to the Tipper 

 (Silurian of Bain which are found in the Cederberg as well as the 

 passage of the former into the felspathic rocks of jSTamaqualand. 

 Bain has no hesitation in affirming this change, and I have every 

 reason to think that he is correct ; but believing as 1 do in the identity 

 of his clay-slate and the Upper Silurian, I cannot but regret that I 

 was unable to make a thorough examination of the country. I believe 

 Bain's separation of the clay-slate from the Upper Silurian (Devo- 

 nian) are drawn here as elsewhere from the position of the quartzite 

 crossing the slate and underlying the Devonian. Is not this evidence 

 identical with that on which metamorphic formations are assigned to 

 widely distant epochs in Europe ? 



In addition to the want of time and of experience referred to, I 

 have to regret the loss of a note-book in which my observations on 

 the rocks in the earlier as well as later part of my journey in Nama- 

 qualand were inserted. I cannot therefore tell from my own obser- 

 vations how the strike of the rocks which was north 30° west at 

 Olifant's river, assumes a nearly east and west strike at Springbok 

 Vontein. As we pass northwards it takes a more northerly direc- 

 tion, and at Oograbis it is north 60° west, and at Annies, on the 

 Orange river, it resumes its north 30° west strike with its slaty 

 character. I have no hesitation in affirming the passage of the slate 

 into felspathic rock here. 



Assuming, then, the metamorphosis of palaeozoic rocks into gneiss, 

 mica-schist, etc., I will merely reiterate my firm belief that those of 

 Namaqualand are the changed condition of the great mass of slaty 

 beds which extend from the mouth of the Fish river in the east to 

 Cape Town, and thence to Olifant's river, and at various points con- 

 tain fossils which have been referred to the Devonian epoch by 

 geologists of Europe. I again admit that the evidence by which I 



