Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/670

 the Koega seem to be very similar in character to those of the Government Saltpan — so much so that one is almost led to believe that they must be a continuation of them. Section K (see fig. 6, e) was made by me near this river, not far from the old road to Grahams- town. In this section, No. 1 (at the top) is a marly clay, interspersed with very numerous, small, calcareous seams. This is comparatively recent, and rests on a conglomerate of quartzite pebbles (No. 2). Immediately beneath this is clay (No. 3), resting upon a coarse loose sandstone (No. 4), and this upon a hardened clay.

Two or three miles lower down the Koega, where I obtained another section, the sandstones appear to be very similar, in their lithological character, to those shown in the section (Section L) of the upper rocks at the Bethelsdorp Saltpan (see fig. 6, 4). I have not found any fossils in them, nor have I heard of any being found ; we must therefore look for some further proofs before a positive opinion of their identity can be formed. This last-mentioned section on the Koega is capped with the same Posttertiary shell-limestone as at the Zwartkops.

Bethelsdorp Saltpan. — On the west side of the Bethelsdorp Saltpan is a very good section of the saliferous clays and sandstones. Commencing from the lowest in Section M1 & M2 (see fig. 6, 5), No. 22 is a coarse, gritty, rather loose sandstone, the thickness of which is at present unknown, as is also the thickness of the belt of clay (No. 21) resting upon it. It is highly probable, however, that the latter, if properly exposed, would prove to be banded clay and sandstone, some 2 or 3 feet thick, similar to Nos. 15 a, 17, and 19. No. 20 is a hard, compact, fossiliferous sandstone, not more than 1 foot thick. In this the characteristic fossils of the locality are found, namely the remains of Cidaris pustulifera. Its plates and spines are obtained here in large quantities. Judging from the numerous remains, one is led to the belief that it was during the period of the deposition of this particular zone that it most flourished, while at the Government Saltpan these fossils appear scarce. Ostrea Jonesiana is also frequent in this belt, whilst other small Ostreoe are scarce. Dr. Rubidge found Crassatella complicata here. Above this fossiliferous bed we find fifteen alternate bands (altogether 10 feet 9 inches) of a reddish clay and sandstone (stratum 19), each bed being very distinctly marked. These bands seem to be non-fossiliferous, as well as the other strata from No. 19 to 14 in Section M 1 & 2, and from No. 11 to 8 in Section L. More diligent search, however, may discover traces of life not only in these rocks, but also in the upper strata before alluded to, on the banks of the Koega (Sect. K, fig. 6, 6). Above No. 19 in Section M 1 & 2, is a coarse non-fossiliferous sandstone (No. 18), 8 feet thick ; then follow banded clays and sandstones (No. 17) 3 feet 6 inches ; and above these, 4 feet 8 inches of sandstone (No. 16) ; again alternate bands of clay and sandstone (No. 15 a), 5 feet 3 inches thick ; then 2 feet of a light-coloured friable sandstone (No. 156), on this a band of 8 inches of clay (No. 15 c), and above that 4 feet 4 inches of a light- coloured and very friable sandstone (No. 14). On the top