PHYSIOGRAPHY OF AUSTRALASIA. 



THE SYDNEY OBSERVATORY. 



GEOLOGICAL FORMATION. 



J "* 1 1 E geology of Australasia is of special 



' interest. The vast Island Continent of 

 Australia is built up of formations correspond- 

 ing to those composing other parts of the globe; 

 at the same time, it possesses features peculiar to itself, and 

 thus a new field of research is presented. A geologist landing 

 upon these shores at once recognizes rocks similar in charac- 

 ter, and in some of their embedded fossil remains, to those 

 with which he is familiar; and he is inspired with new zeal 

 when he finds evidence of life-remains not known elsewhere, 

 which enables him to add to the present incomplete know- 

 ledge of the past life-hist'ory of the earth. Besides this, por- 

 tions of Australia have existed as dry land from remote geo- 

 logical periods to the present day, and hence, as might be expected, our living fauna 

 and flora include ancient types. For a long period these old land-surfaces appeared 

 as comparatively small islands. Some idea of the depth of the ocean that surrounded 

 them may be formed from the fact that the layers of marine sediment, which form 

 the great plains of the interior, have been pierced by the boring-rod to a depth of 

 over one thousand six hundred feet, and then not passed through. 



Australia, once small islands, but now a vast continental area, may, therefore, not 

 inaptly be looked upon as foreshadowing the growth of the future nation into which, from 



