TERTIARY AND RECENT DEPOSITS 417 



springs are of this kind. The water from the Caledon 

 springs contains much ferrous carbonate, and the Warm 

 Water Berg spring water has a smaller quantity of the 

 same salt in it. Sulphuretted hydrogen is a constituent 

 of the Malmesbury, Cradock, and Graaff Keinet mineral 

 waters. 



The majority of these springs rise in Table Mountain 

 sandstone areas, but their distribution is not connected 

 obviously with the great dislocations or folds visible in 

 that formation ; there is no spring situated on or near 

 the largest strike faults, those of Worcester and the 

 Cango, nor does one occur in the more intensely folded 

 portions of the east and west ranges south of the Karroo. 

 The Olifant's Biver (Clanwilliam) hot-bath is on the 

 eastern limb of the gentle anticline that forms the Car- 

 douw Mountain ; the hottest spring, that of Brand Vlei, 

 is near the locality where the dip of the Table Moun- 

 tain sandstone south of Worcester changes from north 

 to east ; the Caledon, Warm Water Berg, Montague, 

 and Olifant's River (Oudtshoorn) springs issue from the 

 sandstone on the flank or at the end of anticlines. 



The Malmesbury spring flows from a mass of granite, 

 and those of Cradock, Graaff Reinet (cold) and Aliwal 

 North l from the nearly horizontal Karroo formation in 

 the great interior basin. It is remarkable that the 

 Malmesbury and Karroo mineral springs contain sul- 

 phuretted hydrogen, while the others do not. This gas, 

 in small quantities, is given off by many of the ordinary 

 springs in the Karroo, and is probably derived from 

 the decomposition of pyrites. Whether the gas in the 



,p. 78. 



