1870.] 



GETESBACH &EOLOGT OF NATAL. 



61 



terial as the underlying stratum. They consist of sandy marls and 

 hard sandstones of a greyish-brown colour, with a few calcareous 

 concretions. These rocks are partly covered at high water by the sea, 

 which has hollowed out small cavities in them (Fig. 5). They have 

 probably served at some period as a shelter for white people, as the 

 natives of this district call them " Izinhluzabalungu," houses of the 

 white men. These rocks only extend for a short distance, and only 

 form isolated cliffs. They are found, too, at the Impengati river, and 

 at some of the more southern rivulets which run into the sea be- 

 tween the boundary of Natal and the St. John's river (Umzimvooboo). 

 The same are also recognized in the bed of a small stream, running 

 into the St. Lucia bay, in the Zulu country. The strata forming these 

 deposits are perfectly horizontal, and they rest upon a sandstone of 

 much older age, which belongs to the very interesting series of the 

 Karoo formation. It is remarkable that the Izinhluzabalungu 

 rocks do not rest conformably upon the older formation, the plant- 

 bearing sandstones. 



Fig. 5. — Izinhluzabalungu Caves. 



<i. Karoo shales and sandstones, b. Sandstone with fossil wood &c. c. Tri^ 

 ^oma-bed. d. Ammonite-bed. e. Gasteropoda-bed. /. Zone of Am- 

 monites Gardeni. 



I have been enabled to distinguish no fewer than five distinct 

 faunas. The lowest stratum is a hard calcareous sandstone (6), very 

 much worn by the sea breaking against it at high water. Large 

 trees and branches are imbedded in it, lying about in aU directions. 

 The wood is traversed by large masses of Teredo, whose holes are 

 filled vsnth iron pyrites. Eesting on this stratum is a bed of softer 

 brown sandstone (c), with great abundance of Trigonice. This bed is 

 more exposed near the Umzambane river, and nearly concealed at 

 the northern end of the deposits. It is overlain by sandstones and 

 grits (d), containing Ammonites, resting upon which is a softer 

 sandstone and grit (e), containing many fossils, mostly bivalves and 

 Gasteropods. The roof of the caves is formed by a harder lime- 

 stone stratum (/), which has not been so easily worn away by the 

 sea as the underlying sandstone stratum. This limestone contains 

 Ammonites Gardeni, BaUy. 



