SECTIONAL TRANSACTIONS.— H. 375 



I have already outlined the East African sequence (worked out before Dr. Simpson 'i^ 

 and Dr. Brook's theories were known to us) and it is obvious that it fit« in 

 very well. 



The later climatic fluctuations must also be considered. 



According to Brooks, certain events stand out as of more or less world-wide 

 occurrence and not as local fluctuations. They are : — 



1. The Biihl advance, after the Achen retreat. 



2. The warm, dry period of the climatic optimum circa 5000 to 3000 B.C., and the 

 Sub- Atlantic wet period of circa 850 B.C. 



In Kenya we have reason to believe that the Nakuran or second post-Pluvial wet 

 phase was not earlier than 3000 B.C., owing to the presence of beads in deposits of the 

 Nakuran phase which are almost certainly not earlier than that and are probably 

 later. On many grounds there is reason to correlate the maximum of Nakuran wet 

 phase with that at 850 B.C. In that case the climatic optimum would equal the dry 

 period between the Makalian and Nakuran at about 5000 to 3000 B.C., followed by a 

 gradual amelioration of climate which culminated in the maximum of the Nakuran 

 wet phase about 850 B.C. 



The Biihl would then equal the maximum of the Makalian wet phase, and the gradual 

 decline from the maximum of the Makalian to the period of desiccation would equal 

 the fluctuations during the period between the Biihl and the Climatic Optimum. 



For the moment, accepting the suggested Glacial Pluvial correlation, we may 

 compare our evidence with that of Europe (on the continent). This comparison is 

 set out in the accompanying table (see folder). 



Mr. Simmons expressed his regret that Mr. Wayland's contribution to the discussion 

 had been delayed in transit. He thought that the evidence from Uganda 

 would, on the whole, favour the idea of an earlier and a later pluvial period in the 

 Pleistocene. 



[A summary of Mr. Wayland's contribution will be found at the close of this 

 report.] 



Mr. Leslie Armstrong, in discussing Early Alan and the Correlation of Glacial 

 Deposits and Pluvial Periods, said that the deposits excavated in the Pin Hole 

 Cave, Creswell, have yielded clear evidence that a cold, wet period marked the 

 termination of the Upper Palajolithic age in northern England. ('? a minor glaciation.) 

 The associated culture is a developed Aurignacian, which appears to be the British 

 equivalent of the upper Magdalenian of France, and contemporary with it in time. 

 Beneath this level are zones of upper Aurignacian and proto-Solutrean cultures with 

 faunal evidence indicative of moderately warm climatic conditions and an inter- 

 glacial phase. At the base of these is an upper Mousterian cultural level resting upon 

 the lower cave-earth and associated with a cold fauna. The lower cave-earth contains 

 definite evidence of glacial conditions having prevailed during two periods, separated 

 by a comparatively short, warm, interglacial phase ; also evidence of two periods of 

 prolonged submergence due to the ponding back of water in the ravine to a maximum 

 height of 30 feet above the present stream level. If this evidence represents one 

 glacial period as a whole, viz., two advances of the ice-sheet and an interval of retreat 

 (which is the view I favour), then the fauna represented in the inter-glacial phase 

 points to warm climatic conditions of considerable duration as lion and giant-deer 

 are fairly abundant, and horse and bison are common. The human artifacts in this 

 interglacial zone are of middle Mousterian culture. I equate this glacial period, as 

 a whole, with the third major glaciation of England. (? Wiirm.) Beneath the 

 glacial beds is a zone of lower Mousterian culture, the oldest in the Creswell succession, 

 associated with a moderately warm fauna. (? Riss-Wiirm interglacial.) For the 

 remainder of the lower Palaeolithic series I adopt the East Anglian evidence and 

 equate them as indicated upon the accompanying chart. 



It is generally conceded that in N.W. Europe we have evidence of four glaciations 

 of major intensity, each separated by a comparatively short interglacial phase and a 

 warm climate, and the respective pairs of glacials separated by a long interglacial 

 phase. Simpson and Brooks, on meteorological evidence, have demonstrated that 

 each pair of glacial periods with the intervening warm interglacial phase, should 

 coincide with a pluvial period in unglaciated regions. On this h3''pothesis there should 

 be in equatorial regions two major pluvials to correspond v ith the four major glacials 

 of N.W. Europe, and minor pluvials, or wet phases to correspond with the later glacial 



