TRANSACTIONS OF SECTION C. 371 
the blocks of the so-called Permian breccias were merely eroded veins or 
filaments of mineral which could be seen inside the rocks if they were broken 
across, and that there was little similarity between the wadi-breccias of Egypt 
and the moraine-breccias of Antarctica, With regard to Mr. Du Toit’s remarks 
on salt-pans he agreed that dunes to leeward pointed to erosion and that there- 
fore-we should expect to find a great accumulation of dunes to leeward of the 
Egyptian Oases: such accumulations are wanting. Professor Penck’s observa- 
tions on the poleward movements of deserts could be interpreted in two ways: 
either the in-draught of air towards the equator carried sand from temperate 
zones on to the sub-desert areas, thus rendering them essentially deserts and 
causing a poleward migration of their edges; or, and this has an important 
bearing on the size of Polar ice-caps, our earthly boiler and condensers (the 
Tropics and the Poles) are losing in efficiency, and consequently both regions 
are becoming drier. The Wastwater Screes were a known example of breccias 
forming in a region whose climate is hardly desertic. 
Mr. Ferrar said he was well aware that the Nubian Sandstone was exposed 
in the floors of the oases and that vast quantities of rock-material had been 
removed, nevertheless he still found himself in Professor Walther’s position of 
ten years ago, and, after seeing wind-driven sand tending to fill the oases- 
depressions and not excavate them, did not think the wind-erosion theory con- 
sistent nor a sufficient explanation of their origin. He holds the view that 
wind-erosion tends to remove all rugosities and that the ultimate physiography 
of an arid land-surface is a smooth level plain. 
With regard to Sir Thomas Holland’s criticism as to quantitative results, 
Mr. Ferrar suggested that data, similar to that collected in Rajputana by the 
Indian Geological Survey, could be obtained by measuring the quantity of sand 
brought in to the oases at their northern ends and the quantity carried out 
southwards. Any difference would show the rate of erosion or deposition, 
according to sign. 
In concluding his remarks Mr. Ferrar thanked his audience for their interest 
in and their appreciation shown towards his papers. 
After remarks by Mr. D. M. S. Watson, the discussion closed. 
WEDNESDAY, AUGUST 19. 
The following Papers were read :— 
1. On the Age and Sequence of the Tertiary Strata of South-Eastern 
Australia. By Frepericx Cuapman, A.L.S. 
Divisions of the Kainozoic. 
It is convenient to divide the Australian Tertiary system into four or five 
main series, using the local terms suggested by Hall and Pritchard. In ascend- 
ing order, these, according to the writer, are :— ; 
1, Balcombian. 2, Janjukian. 3, Kalimnan. 4, Werrikooian. Above these 
comes the Pleistocene series, referred by many geologists elsewhere to a separate 
system, the Quaternary. 
These divisions, broadly speaking, correspond with :— 
1, Oligocene. 2, Miocene. 3, Lower Pliocene. 4, Upper Pliocene. 
The present writer maintains that, giving due allowance to time discrepancies 
in regard to the factor of distribution of life-forms over wide areas, guide fossils 
are probably as important in dividing and allocating these beds to the well-known 
horizons of the northern hemisphere as are percentages of living forms in these 
fossil deposits. The percentage method can only be used with safety as an 
approximate guide to age, seeing the difficulty of obtaining an agreement amongst 
zoologists as to what constitutes a species. 
The above series of European divisions correlated with the Australian 
corresponds almost exactly with McCoy’s original determinations, augmented by 
BB 2 
