Fauna and Stratigraphy of the Stormberg Series. 469 



of red sediments and calcareous sediments precludes the possibility 

 of any arid or very dry intervals. 



The abundance of felspar in the sandstones proves that decomposition 

 was not very complete, and argues a somewhat cool climate with 

 discontinuous rainfall. The presence of boulders and pebbles can be 

 explained by occasional torrential downpours following on periods 

 of comparative quiescence in which vegetation was able to flourish. 



It is possible that part of the lower Molteno Beds at least are 

 formed of material that was accumulated on the land surfaces during 

 Upper Beaufort times. During the comparatively cold periods of the 

 Beaufort fairly deep disintegration of the rock-surfaces to the south 

 took place, resulting in the formation of a mass of undecomposed 

 felspar, quartz and other grains which, on the incoming of Molteno 

 conditions accompanied by earth-movement, formed the material 

 which built up the foundations of the Molteno Beds by transport 

 northwards. 



The nature of the coal-seams and of the fossil plants associated 

 therewith is of considerable interest. The conclusion expressed by 

 Rogers and du To it as to the formation of the searns requires some 

 modification. In the first place the often perfect preservation of the 

 plants, which are mainly delicate and fragile fronds of ferns and 

 fernallies, precludes the possibility of their having been transported 

 far from their place of growth by river-torrents. There is little or 

 no maceration shown by the fossils, except occasionally in the sand- 

 stones, and it is more reasonable to suppose that the plants were 

 buried near to the swamps in which they grew and flourished. 



Such swamps occupied discontinuous areas in the region; for, al- 

 though contemporaneous erosion is the explanation of the lack of 

 coal seams in certain parts, their absence in others is most likely due 

 to an original absence of swampy ground. Such discontinuity in 

 swamp conditions is a feature of flood-plains in an intermittently 

 rainy climate rather than in continuously rainy regions. It is just 

 possible that the conditions were nearly the same as those described 

 by Davis from Turkestan where there is an alternation of inundations 

 and drought. During the former, and following it, vegetation temp- 

 orarily springs up, withers, and gives place to desert conditions until 

 the next flood. Such alternation would possibly result in thin coal 

 seams intercalated in thin sandstones or shales; but conditions of too 

 great dryness would not be favourable to the formation and preser- 

 vation of plant fossils. 



Red Beds. The most striking feature of the Red Beds is the colou- 



