254 STRATIGRAPHY 



The followmg is a descending section of the coal seams in order in another part 



of the basin : — 



0-20 metre 

 4-00 „ 



As regards information then, up to the present the total thickness of coal in the 

 Santa Catarina system of South America varies from about 13 feet to 20 feet, while 

 that of the coal at the great nunatak at the head of the Beardmore Glacier, inclusive 

 of some clay bands, is about 25 feet. There can be no question, in our opinion, that 

 there is a very large coalfield on the dovsoithrow side of the great horst westwards. 

 This coalfield has to be estimated by such amounts as 100,000, possibly several 

 hundred of thousands, of square miles. For example, if it were 700 miles in 

 length and 143 miles in width from east to west, it would have an area in round 

 numbers of 100,000 square miles. At the most conservative estimate of only 

 100,000 square miles, and if only a thickness of 12 feet of the coal be workable, about 

 one billion and a quarter, say approximately one billion tons, of coal would be 

 available, that is, about ten times as much as is roughly estimated to be available for 

 output at present in the unworked coalfields of the whole of New South Wales. 



It is possible, therefore, that in the far future, if deglaciation makes this coalfield 

 accessible to man, it will prove an important factor in the world's supply of fuel 

 when existing coalfields have been largely exhausted.* 



If the Beacon Sandstone formation is considered the equivalent of the Permo- 

 Carboniferous coal-measures of Australia, it seems strange that no trace has been 

 observed of any glacial beds associated with it. Mawson has already suggested that 

 the abundance of undecomposed felsjmr in the sandstone implies a dry climate, 

 perhaps like that of a tundra. It is of course conceivable that tundra conditions 

 might jjrevail at a pole when intense glaciation was being experienced in compaia- 

 tively low latitudes, as unless the polar regions could be fed under those circumstances 



* Some deduction should be made fiom the quantity of exploitable coal on account of the damage 

 caused to the coal by the intrusive sills of dolerite. 



