Marshall. — The Glaciation of New Zealand. 343 



American geologists at the present time believe that the glacial advance 

 took place at different times in different parts of the glacial region. It 

 was earliest in the west, spread eastwards, and is now at its maximum 

 in Greenland. 



Another wholly different line of reasoning will naturally make us hesi- 

 tate to adopt the idea that a reduction of temperature in New Zealand, 

 associated with a similar reduction in South Victoria Land, would cause an 

 ice-sheet from the former to extend northwards to the latter. Captain 

 Scott, as a result of the " Discovery " expedition, recognised that the Great 

 Barrier during the greater glaciation in the south extended over the whole 

 of the Koss Sea : and this is the greatest ice-extension in the south that 

 has yet been suggested by any of those who have visited these regions. 

 The Ross Sea, it must be remembered, is a relatively shallow area of water, 

 for only two soundings have been made that indicate a greater depth than 

 300 fathoms. Captain Scott states that at the time of this ice-extension 

 the mean temperature must have been higher than to-day. This is ac- 

 cepted as a " natural conclusion " by Philippi, and is also adopted by David. 



It therefore appears that a decrease of mean temperature in New Zealand 

 was not necessarily associated with a lower temperature in South Victoria 

 Land ; and, even if there was this association, a glacial advance would 

 probably not result. 



There is at present no known instance of a continental ice-sheet ex- 

 tending far over deep oceanic water. That of Greenland stops short of 

 the coast everywhere except at the heads of some of the fiords. In South 

 Victoria Land the Great Barrier terminates in water that is almost every- 

 where less than 300 fathoms. The " Belgica " expedition, in longitude 90°, 

 as it approached' the edge of the ice got frequent soundings less than 

 300 fathoms. Bruce, as he approached Coats Land, got two soundings less 

 than 200 fathoms. The German expedition in the neighbourhood of Kaiser 

 Wilhelm II Land found similarly shallow water : in two cases the depth 

 was less than 200 fathoms. Thus, even in this greatest known of ice-sheets 

 the northern face of the ice in no place where soundings have been made 

 extends into deep water — in fact, it now^here extends beyond the shallowest 

 fringe. The importance of this is realised when it is stated that, so far as 

 known, 1,400 miles of water more than 1,500 fathoms deep separates the 

 Ross Sea from New Zealand. 



It is also a remarkable fact that the ice seldom extends from island 

 to mainland except where the water is quite shallow. There are manv 

 instances of this in the south. The Palmer Archipelago, Coulman Island, 

 the Balleny Islands, are all examples. In the north, Spitzbergen is separate 

 from Greenland, while its islands and those of Franz Josef Land are separate 

 from one another. Still more remarkable, Grinnell Land is not united to 

 northern Greenland, though the strait between them is extremelv narrow 

 and shallow. In Europe, the Scandinavian ice-sheet extended to Britain 

 during the Pleistocene glaciation. As the water of the North Sea is almost 

 everywhere less than 100 fathoms deep, this cannot be quoted as an instance 

 of the extension of an ice-sheet across deep water, especially as geologists 

 agree that at that time the whole region was more elevated. A consider- 

 ation of these facts shows us that remarkably strong proof is necessary 

 before we are justified in countenancing the idea that New Zealand and 

 South Victoria Land were in the past united by an ice-sheet. 



No geological evidence of this connection has yet been put forward, 

 unless we accept the statements of the thickness of ice at Wakatipu as an 



