BY THE REV. J. MILNE CURRAN. 197 



Bathurst now stands. Evidence is accumulating to show that the 

 Devonian rocks, found both to the east and west of Bathurst, once 

 formed a great anticlinal fold over the granite. This, probably, 

 formed an island in Carboniferous and Jurassic seas. But all 

 direct proof is missing and practically nothing is known of the 

 physical surroundings of this district from Devonian to Jurassic 

 rimes. The most tenable opinion is that we had dry land here- 

 abouts when the Carboniferous formations to the north and west 

 were being deposited. This means that rivers from Bathurst 

 mountains flowed into Carboniferous and probably Mesozoic 

 seas, and that our hills were old when many parts of Europe 

 and Asia were still under water. 



The drifts referred to are all alluvial, marine deposits being 

 quite unknown. Every drift about Bathurst owes its origin to 

 the present river. The oldest deposit is some 540 feet above the 

 present bed, so that the amount of eroded matter is very consider- 

 able. By joining the basalt hills marked F, A, H, K, on the 

 accompanying map (PI. xvni.), the bed of the old pliocene river may 

 be approximately traced. These basalt hills were, there is no 

 doubt, once continuous, and the gaps now present are the result of 

 subaerial denudation. The history of the changes, since the days 

 when the Macquarie flowed through this channel nearly 600 

 feet above its present level, is shortly this. The river was the 

 main drainage line of the country, therefore, the lowest depression 

 within the water-shed. Active volcanoes were pouring out floods 

 of lava about Swatchfield and Orange. One of these streams of 

 liquid rock flowed down and filled up the valley of the Macquarie. 

 The river waters were thus displaced and forced to erode for them- 

 selves a new channel. The granite proved more yielding than the 

 compact basalt, so that while the basalt remains the granite has 

 been subjected to every agent of denudation. In effecting this we 

 can with much reason suppose the river to have been a far greater 

 stream that it is now. Volcanic eruptions are always attended 

 with atmospheric disturbance and heavy rains ; moreover, the 

 rainfall was undoubtedly greater. Then the rock was, in all 



