Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/684

 to within three miles of Prentice Kraal, and nearly in the same meridian as Blaaw Krantz. This latter place, however, is some three or four miles off the limestone. It is seen upon Landman's Kop, a hill lying just eastward of the Sundays River's mouth, and at Deep Kloof and Groof Water, in Oliphant's Hoek, twenty miles south of the Sundays River. To the southward of Port Elizabeth the limestone hills of Buffel's Vontein, Chelsea, and Tan Staden's River, are probably of the same formation."

Mr. Pinchin's professional duties have given him opportunities of visiting every part of the district. The places which I have examined are : — Rocke's Bluff ; a quarry on the flat between the Government Saltpan and the Zwartkops Heights ; on the banks of that river, to a deep kloof, a little below the drift (ford) on the old Grahamstown Road ; the old waggon-track on the north bank of the Koega, near the Kopjes; different spots on the Grassridge ; and at McLoughlin's Bluff. It seems to be a single deposit, and not a series like the others (see p. 519). It varies very little in all the localities that I visited, being from 4 to 6 feet thick, except at McLoughlin's Bluff, where it is much thinner. It is highly fossiliferous, and abounds with fragments of shells, and now and then with some that are nearly perfect. Of the bivalves only single valves are found, and the majority have been broken by the action of the waves. In some localities there are immense deposits of a large species of Ostrea. Out of 22 different species of shells, nine are not at present found on the neighbouring coast, five are still doubtful, leaving only eight of the number that are positively recognized as being inhabitants of the present sea.

2. Pliocene or Postpliocene Strata on the Coast. — Following this limestone, and with an evidently wide interval, is a series of deposits which are spread out from Port Elizabeth to the mouth of the creek (or Ferreira's River), and thence, in detached spots, to the Zwartkops. The oldest deposit appears to be a sandy tufaceous (?) limestone, interspersed with many patches of conglomerate, formed of small quartzite pebbles. It is very fossiliferous. Out of twenty-five species of shells that I collected from this bed, twelve have not been found in the adjoining sea. The - greater portion of these are fragments. This deposit was certainly laid down under widely different circumstances from those of which I shall have to speak presently, and in which the shells, however fragile and delicate, are in a beautifully perfect state.

As far as I could judge from an excavation I had made at the foot of the cliff, I found this stratum to be from four to eight feet thick ; but I found great difficulty in obtaining a good section, as, at the lowest level arrived at, the water flowed in so rapidly that we could not proceed. The bed extended from a quarter to half a mile inland, where it was hidden under the aeolian sandhills. It was covered by a non-fossiliferous limestone, a few inches thick ; and above that was spread a layer of loose pebbles of the same kind as those in the pebbly limestone itself.