252 STRATIGRAPHY 



F. Wild suggests the following, reading from above downwards, as an approximation 

 to the section : — 



1 foot to 1| feet, coal seam. 



Strata. 



7 feet, coal seam with bands of grey shale. 



Strata. 



5 feet, coal seam, apparently formed of clean coal. 



Strata. 



3 feet (about), coal seam. 



Strata. 



3 feet (about), coal seam. 



Strata. 



3 feet (about), coal seam. 



Strata. 



3 feet (about), coal seam. 

 As regards its horizontal extent, the Beacon Sandstone has now been traced from 

 85° S. lat. up to Mount Nansen in 74° 35' S. lat., a distance of 625 geographical 

 miles, or over 700 statute miles. While it has this extent from north to south, the 

 Beacon Sandstone formation extends certainly for a distance of over 50 geographical 

 miles from east to west, and to judge from the inclosures of sandstone in the material 

 of the parasitic cones of Mount Erebus, it probably continues for a farther distance 

 of about 30 miles east, that is, a total proved east and west extent of about 80 

 geographical miles, or 93 statute miles. 



It is premature to estimate the gross quantity of coal within this area even 

 approximately. All that can be said in this relation is that the superficial area of 

 the Beacon Sandstone formation has already been proved to be originally in romid 

 numbers over 60,000 square miles ; but from this has to be deducted a strip of 

 variable width on the upthrow side of the great horst, from which the Beacon 

 Sandstone has been denuded away. This strip may have an average width of about 

 20 miles, which would give an area of 14,000 square miles to be deducted from the 

 original 60,000 ; this leaves 46,000 square miles. From this again further deduc- 

 tions must be made to allow for the Beacon Sandstone having been completely 

 denuded off the highest parts of the horst in places, as at Mount Larsen, Mount 

 Gerlache, Mount Bellinghausen, Mount Neumeyer, &c. This would still further 

 reduce the area by probably at least 6000 square miles, thus leaving 40,000 square 

 miles of this area. About 28,000 square miles would lie on the downthrow side of 

 the great fault between the west coast of McMurdo Sound and Erebus, and would 

 be considerably below sea-level. This would leave only about 12,000 square miles 

 of Beacon Sandstone actually now exposed above sea-level in the plateau of the 

 great horst, which would represent the whole amount available for coal-mining at 

 present if the coal-measures were developed over the whole of this area. It is 



