BY W. G. WOOLNOUGH. 489 



Still more conclusive evidence of the age of the granites is 

 atibrded by the section at Nasoqo. Here, at a point of over 800 

 feet above sea-level, there is a tuffaceous conglomerate cotitaiyiing 

 well worn pebbles of granite associated with Tertiary fossils. 

 This proves conclusively that the granite must be at any rate 

 Pre-Tertiary, and probably much older. This fact is of extreme 

 importance. 



As already stated, the great objection to the continental theory 

 is the depth and extent of the ocean between Fiji and the nearest 

 considerable area of continental land. This objection is to a 

 certain extent answered by the fact that there are numerous 

 instances in which the earth's crust can be proved to have under- 

 gone movements sufficient to account for the great depth of water. 



In the case of the great Uinta Fold of Colorado, White"^ 

 estimates the total vertical displacement at 28,000 feet. 



In the case of Madagascar, above cited, the Mozambique 

 Channel, with a depth in parts of over 2000 fathoms, has been 

 proved to be the result of a series of trough faults. 



The Great Rift Valley of Africa may be taken as still another 

 instance of a slice of country which has been let down by a series 

 of parallel faults, the aggregate displacement being 4000 to 5000 

 feet. 



Coming nearer home, the great coal basin under Sydney affords 

 a magnilicent instance of the flexibility of the earth's crust. 

 According to the section given by Professor David,! the subsidence 

 in this area amounts to at least 7000 to 8000 feet. 



In the South Wales Coalfield there is a series of fresh water 

 coal-bearing strata which reach a maximum depth of 12,000 feet. 

 As these strata were formed at the earth's surface, we have here 

 evidence of a depression amounting to 2000 fathoms. 



* White, C. A., "On the Geology and Physiography of North- Western 

 Colorado and adjacent parts of Utah and Wyoming." Ann. Rep. U.S. Geol. 

 Survey, ix., p. 696. 



+ Pres. Address, Journ. Eoy. Soc. N.S.W., xxx., 1896. 



