STOW — SOtJTH-ArKICAN GEOLOGY. 507 



of all these lies an irregular deposit of a sandy calcareous tufa, 

 covered with a reddish sandy clay. The remarkably uniform thick- 

 ness of the several clays and sandstones in these sections is worthy 

 of notice. 



Prom another Section, marked L (see fig. 6), that I was able to ob- 

 tain in a higher bank about 300 or 400 yards to the N.N.E. of 

 Section M 1, 'No. 14 does not appear to be the uppermost in this 

 series. This higher section shows nearly the same dip as the lower 

 one ; and in it we find a broad band of sandy clay (No. 11) 8 feet 

 in thickness, interspersed with a great number of calcareous stripes 

 near the top. Above this is 2 feet of clay (No. 10) of a pale-greyish 

 stone- colour, (No. 9) six inches of a sandy yellow and brownish 

 striped clay; and above that, (No. 8) two feet more of the same clay 

 as No. 10, with a superficial loam. In the foregoing sections, 

 we therefore obtain (if the uppermost bands belong to the series) 

 a combined thickness of more than 52 feet of these stratified clays. 

 The latter section is capped with the same reddish sandy clay as the 

 former ; and I have not been able to find in these two places any 

 trace of a deposit that might be considered the equivalent of the 

 Zwartkops and Koega Posttertiary shell-limestone. 



The Salt Vlei near Port Elizabeth. — About five miles nearer to 

 Port Elizabeth, in the clay-pits, at a place called Salt Vlei, we find 

 another excellent section of the stratified clays. This is shown in 

 Section N (fig. 6, 2). In these pits the lowest uncovered rock is that 

 marked No. 18 in the section — namely, a marly, gritty sandstone. 

 It is exposed for a depth of 14 feet ; the remainder of it (whatever 

 the entire thickness may be) is covered up with the debris of the 

 excavation. It appears, as far as can yet be seen, to be non-fossili- 

 ferous. Immediately above this is a belt of clay (No. 17), and on 

 the clay a band of nodular concretions (No. 16) fourteen inches thick. 

 These nodules are irregular in shape, and of various sizes, some of 

 them being upwards of 2 feet in length ; when broken they all 

 display the same fracture as that shown in specimen No. 16*, with a 

 powdery nucleus as in specimen No. 16 af. In situ, they lie as if 

 they had been regidarly packed, their greatest length being in the 

 direction of the dip. 



Above this noduliferous band is a sandy clay. No. 15, 2 feet 

 thick, of a yellow-ochre colour. Upon this follows a dark slate- 

 coloured clay. No. 14, also 2 feet thick. The strata Nos. 14, 12, and 

 10 are clays to all appearance exactly alike, as regards colour and 

 texture, and must have been deposited under similar circumstances. 

 No. 13, 1 foot thick, is the first zone (in this section) in which were 

 found traces of fossils. It is full of small marine shells [Astnrfe (?) 

 and Natica or Phasianella (?), T. E. J.] : some are very beautiful ; 

 and all were so delicate in structure as to be very difficult to remove. 



No. 12 is a clay, 3 feet thick ; then comes a single line of 

 nodules. No. 11. These nodules are placed either singly or in groups, 

 as shown in the section, all in the same line of bedding. No. 10 is 



* No. 16. Ferruginous sandy nodule, with ochreous centre.— T. E. J. 

 t No. 16a. Dark red-purple earthy hsematite. — T. R. J. 



