"202 TERTIARY ROCKS OF AUSTRALASIA, 



eroded on taking another direction. In many places along 

 the high lands of the Great Dividing Range the basaltic 

 lava completely filled the shallovrer valleys and formed 

 extensive plateaux, such as we see in the New England 

 District." It is remarkable how applicable these remarks 

 of Mr. Wilkinson are with respect to Tasmania. The 

 description could not be more accurately given if applied 

 to similar formations on the Magnet Range, at Mount 

 Bischoif, and in the valleys of the North and South Esk, 

 near Launceston. 



Climate of the Neogene Period. 



The evidences available with respect to climate are 

 vague and unsatisfactory, as already indicated, p. 155. It 

 is clear, however, that the conditions under which the 

 successive irregular coarse shiugly terrace drifts had been 

 formed in the main valleys were very diiferent from those 

 under which the Palaeogene formations were deposited, 

 and it is also probable — as suggested in respect of 

 equivalent formations in New Soath Wales by Mr. G. S. 

 Wilkinson, and in South Australia by Professor Tate — 

 that the mode of deposition and other circumstances indi- 

 cate a much greater rainfall than at present. The paucity 

 of life in the formations, by itself — while depriving us of 

 the aid of Palaeontology in the classification of the rocks 

 and in inferring local climatic conditions — only affords 

 negative evidence in support of a growing refrigeration of 

 climate. 



Whether this supposed change in the direction of a 

 colder climate became sufficiently intense within the period 

 to produce the local ice sheets and glaciers — of which there 

 is evidence in valleys of the Western Highlands, notably 

 along the deeply cut ravines of the Mackintosh River — 

 it is difficult to determine. It is quite conceivable, how- 

 ever, that simultaneously with the rising of the floor of 

 the old Palseogene sea the adjacent land partook of a 

 corresponding elevation, and we may therefore expect to 

 find, as a direct consequence, a considerable change of 

 temperature over the limits of the areas so affected. 



There is additional support to this view from the circum- 

 stance that in the opinion of Professor Huttoh correspond- 

 ing causes were producing similar effects in New Zealand 

 during the interval between the Pareora system and the 



