418 Notices of Memoirs — Address by Sir T. H. Holland. 



These glacial beds are often referred to in the geological literature as Permo- 

 Carboniferous in age ; but Professor Koken regarded the formation in India as 

 Permian. Other valuations of palaeontological evidence, similar to that relied 

 on by Professor Koken, place these beds at a distinctly lower horizon in the 

 European strati graphical scale, and recent v?ork by officers of the Geological 

 Survey of India in Kashmir tends to confirm this latter view ; we now re2:ard 

 the base of our great coal-bearing system in India — the horizon of the glacial 

 boulder-beds — as not much, if at all, younger than the Upper Coal-measures of 

 Britain.^ The precise age of the horizon is not very important for our present 

 consideration : the important point is that in or near Upper Carboniferous 

 times a widespread glaciation occurred throughout the area now occupied by 

 India, Australia, and South Africa. The records of this great glaciation are 

 thus found stretching northwards beyond the northern as well as southwards 

 beyond the Southern Tropic. 



Now, on the assumption that the cold climate in this region was due to 

 a movement of the crust over the nucleus, Professor Koken has produced an 

 elaborate map of the world, showing the distribution of land and sea during 

 the period, with the directions of ocean currents and of ice-sheets. The 

 Permian South Pole he places at the point of intersection of the present 

 20th parallel S. and 80th meridian E. — that is, at a point in the Indian Ocean 

 about equidistant from the glaciated regions of India,^ Australia, and South 

 Africa. The Permian North Pole is thus forced to take up its position in the 

 centre of Mexico, while the Equator strikes through Russia, Italy, West Africa, 

 down through the South Atlantic and round by Fiji to Vladivostock. 



The very precision of this map reduces the theory on which it is based to 

 a condition of unstable equilibrium. If glacial conditions were developed in 

 India, Australia, and South Africa by a 70° movement of the crust, were the 

 movements to and from its assumed position in Permian times so rapid that 

 the glaciation of these widely separated areas appear to be geologically contem- 

 poraneous? If such movements had occurred, instead of evidences of glaciation 

 over a wide area at the same period, we ought rather to find that the glaciation 

 in each of the widely separated points occurred during distinctly different 

 geological periods. 



But that is not the only weak spot in the evidence. The Permian (or Permo- 

 Carboniferous) glaciation of Australia took place on the east and south-east of 

 the continent as well as in Western Australia, and the eastern ice-sheets would 

 thus have been active within 30° of Professor Koken' s Permian equator. There 

 are still three other serious pieces of colour-discord in this picture. In the 

 State of Sao Paulo — that is, within Koken's 'Permian' tropics — Dr. Orville 

 Derby has described beds which strikingly recall the features of the Upper 

 Palffiozoic glacial beds of India and South Africa. It is possible that these 

 are due to the work of glaciers at a high level ; but, since the publication of 

 Professor Koken's memoir, other occurrences of the kind have been described 

 by Dr. I. C. White in different parts of Brazil, and there is a general 

 correspondence between the phenomena in South America and those in 

 the formations of the same age in the Indian, Australian, and African 

 regions. 



Then, too, if we accept this expression of the physical geography during 

 Upper Palaeozoic times, we must carefully explain away the suspicious breccias 

 and brockrams which have been regarded by many geologists as evidences of 

 a cold climate during Permian times in the Urals, the Thiiringerwald, the 

 English Midland and Northern counties, Devonshire and Armagh — -places 

 that would lie on or near Koken's ' Permian ' equator. Finally, we find the 

 hypothetical Permian North Pole in a locality which has failed to produce any 

 signs of glaciation. 



{To be concluded in the October Number.) 

 ^ H. H. Hayden, Eec. Geol. Surv. Ind., vol. xxxvi, p. 23, 1907. 



