328 THE UMZAMBA BEDS 



It is very probable that the junction is a faulted one, like 

 the junction of the Embotyi beds farther to the south- 

 east. 



The Umzamba beds form a line of low cliffs (see 

 Plate XXII.) extending about a mile north-eastwards 

 from the sand-spit on the left bank of the Umzamba 

 mouth, and they are also exposed at low tide on the 

 shore between the levels of high and low water, where, 

 however, they are frequently more or less concealed by 

 sand. Between the Umzamba and Umtentu Kivers 

 they are exposed between tide marks only, and do not 

 crop out at the back of the beach below the sand dunes. 



The rocks consist chiefly of shelly limestones and 

 hard sandy clays containing much carbonate of lime. 

 These two kinds of rock are interbedded ; the shelly 

 limestones are thinner than the clayey beds, and at the 

 same time offer more resistance to the weather and the 

 sea, so that on the low cliffs they appear as projecting 

 shelves or ledges separated by the softer beds. The 

 latter have been deeply worn away by the sea, thus 

 giving rise to lines of caves, whose floors and roofs are 

 the hard shelly limestones. The native name of the 

 cliffs to the north-east of the Umzamba mouth is 

 Izinhluzabalungu (" houses of the white men "), perhaps 

 in reference to the use of the larger caves by a ship- 

 wrecked crew. 



The shelly limestones are made up of fragments and 

 perfect specimens of many kinds of shells, mixed with a 

 comparatively small quantity of quartz sand. 



Each bed of shelly limestone can be followed for a 

 certain distance along the cliff, then it thins out, and 



