170 The American Geologist. March, 1902 
unstratified portion, exactly correspond in lithological charae- 
ter and mode of deposition on the underlying rocks, to the 
water-laid materials whieh were deposited by the waters flow- 
ing from our Pleistocene glaciers. 
The beds of the upper Karroo series are of a different char- 
acter. They consist of horizontal strata of fine materials, 
clays and sand, free from pebbles and very hard and compact. 
and they overlie the lower Karroo over the eastern portion of 
the Transvaal and over a large part of the Orange Free State. 
They form the plateau of Hooge Veld in the eastern Trans- 
vaal and are cut by numerous dikes of diabase which have 
often spread out so as to cap the plateau. The upper Karroo 
formation gives evidence of being, in the main, lacustral in 
origin and is supposed by Mr. Molengraaf to have been de- 
posited in the quiet waters of glacial lakes which were formed 
during the retreat of the ice. 
We have then, represented in these Transvaal beds of 
Permian age, every variety of glacial material which we find 
in our own Pleistocene deposits. This evidence brought for- 
ward by Mr. Molengraaff is only another link in the chain of 
evidence which has been slowly collecting, not only in South 
Africa but in Australia and in India, of a great glacial invasion 
in the southern hemisphere in Permian times, an invasion 
which rivalled in magnitude our own Pleistocene ice age. 
From Australia* and + and Tasmania are reported numerous 
traces of glaciation, moraines, and polished surfaces, which 
are referred by Mr. F. W. E. David to the permo-carbonif- 
erous. In India we have the Gondwana system of Permian 
age presenting almost precisely the same characteristics as 
the Kkarroo series of the Transvaal, the underlying rocks being 
also scored. 
There seems to be no ground for doubting the contempo- 
raneity of origin of the deposits in these various regions and 
a general period of glaciation in the southern hemisphere in 
Permian times. 
University of Michigan, Feb. 1902. 
+ Davin, “Evidences of Glacial Action in Australia and Tasmania.” Aus- 
tralian Assoc. for Adv. of Science, vol. vi, 1895, pp. 60-98. Also, Trans. Royal 
Soc. of South Australia, vol. xxi, 1897, pp. 61-67. 
TA. PRNCK, Die EHiszeiten Australiens, Zeitschrift Geo. Erd. Berlin, vol. 
XXXV, 1900, pp. 239-289. 
