DIASTROPHISM AND THE FORMATIVE PROCESSES 337 



Also in the Pyrenees there was a stage of folding at about this 

 time. In the Asturias, and doubtless in the greater part of the 

 Iberian Peninsula, folding movements followed the WestphaHan, 

 coming probably before the Stephanian, but in any case before the 

 Permian. From GaHcia in the extreme northwest corner of the 

 peninsula and from the north of Portugal, a number of nearly 

 parallel folded ranges, closely packed, run southeastward into the 

 great Meseta and continue as far as the valley of the Guadalquivir 

 in southern Spain. ^ This intensely folded mountain system in- 

 cludes much of the Carboniferous together with much granite 

 which, for the most part, was intruded during the Carboniferous 

 period. As in the Asturias, here also the upper beds of the Car- 

 boniferous rest unconformably on the folded region, and the general 

 structure of these mountains thus dates, Hke that of the Armorican 

 and Variscan systems, from late in the Carboniferous period. 



South of the Mediterranean there are evidences of Hercynian 

 movements as far as the African Caledonian fold zone.^ In the 

 Atlas Mountains of Morocco the age of the closing Paleozoic folding 

 has not been fixed more closely than between the close of the Lower 

 Carboniferous and the beginning of the Permian. But in eastern 

 Morocco and in south Oranais, the Devonian, Dinantian, and Mos- 

 covian (WestphaHan) are found in concordance just as in Spain, 

 which has led Haug to conclude that they belong to the same 

 geosynclinal and to the same zone of folding. 



In South Africa the most definite bench mark for correlation 

 is afforded by the base of the Karroo System — the Ecca series, and 

 especially its basal formation, the Dwyka conglomerate. Its wide- 

 spread occurrence, its distinctive petrographical characteristics, 

 and the fact that, while conformable in the south of Cape Colony 

 with the uppermost member of the Cape System, it shows a varying 

 degree of unconformity elsewhere, make the Dwyka conglomerate 

 an excellent datum level.^ In the north of Cape Colony, accord- 

 ing to Hatch and Corstorphine, in Natal, Zululand, Rhodesia, 



' Eduard Suess, The Face of the Earth, Sollas trans., II (1906), 126. 

 ^ G. B. Flamand and E. F. Gautier, cited by Haug, op. cit., p. 831. 

 3 F. H. Hatch and G. S. Corstorphine, The Geology of South Africa, 2d ed. (1909), 

 P- 33S- 



