THE CRETACEOUS SYSTEM 293 



bedded in a sparse sandy matrix so that they are often 

 in contact with each other ; they have often been in- 

 dented or cracked by mutual pressure. 



In the upper part of the Zwartkops Valley the con- 

 glomerates are very thick, over 1,000 feet, and the same 

 is the case at Hankey in the Gamtoos Valley. They 

 are overlain as a whole by the beds called Zwartkops 

 sandstone and Variegated marls by Atherstone, but con- 

 glomerate bands are not infrequent in these higher beds. 

 On the right bank of the Zwartkops Kiver below Uiten- 

 hage the red clays are worked for brick and tile making. 

 The thickness of conglomerate below these clays and 

 sands is very slight to the south of Uitenhage, where 

 the Humansdorp Eoad leaves the Zwartkops Valley, 

 but the clays and sands contain thin beds of conglomer- 

 ate. In the clay pits belonging to the Port Elizabeth 

 Brick and Tile Company near Despatch Station bones 

 belonging to a dinosaur, Algoasaurus baini (Broom), have 

 been found. 1 



In the Bezuidenhout's Eiver Valley from a short dis- 

 tance above Blue Cliff Station to a point some four 

 miles above the railway bridge, the rocks lying below 

 the Wood beds are well exposed at intervals along the 

 river banks. They are reddish-yellow sands, red clays 

 and thin sandstones, with occasional pebble beds. Con- 

 glomerates like those of Enon are entirely absent from 

 this valley. Near the fortieth milestone on the railway 

 between Uitenhage and Blue Cliff, greenish sandstones 

 very like some that occur in the Bezuidenhout's Valley 



1 Broom, G. M., 1904, p. 445. 



