530 GEOLOGY OF THE CLARENCE RIVER BASIN, 



deposits, which would permanently raise the land, were their work 

 not counteracted by equivalent subsidence of the foundation. For 

 there is nowhere any sign of real elevation. The coast line within 

 which the rocks of the Clarence basin were deposited has disap- 

 peared, and its position can only be conjecturally determined by 

 careful examination of the palaeozoic q and igneous rocks which 

 appear to the North and South of the entrance. But not only has this 

 ancient barrier vanished, but the overlying horizontal beds also, 

 which now, in miserable fragments, form the outworks of the land, 

 are disappearing in their turn, partly by subsidence, partly by 

 marine erosion, and in large measure under the exigencies of great 

 engineering works. A few inconspicuous headlands are united 

 by long ranges of sandhills, based in some places on rocky 

 reefs, but, in others, filling the deep valleys through which 

 the ancient water courses made their way to the sea. It is by 

 rocks that once were summits of ranges, and not over the filled up 

 channels of the drainage of tertiary times, that the present river 

 makes to the sea. Through shifting sands currents traverse widely, 

 shifting their course without warning or apparent reason. But 

 where there is a rock at their level, they can only shift back and 

 forward from it. Consequently the channel obtains a certain 

 degree of permanence, although at the point where the accumu- 

 lation of sand is shallowest, and a long way from the ancient 

 channel, which had been eroded before to the commencement of 

 the present period of subsidence. 



It may be worth noting that in the course of the dredging 

 operations which are being carried on at Lawrence, the " shackle- 

 bone " of a large whale, together with other portions of the 

 skeleton, were met with at a depth of only two feet or so in 

 the sandy drift. (The " shacklebone" is composed of the flattened 

 cervical vertebrae, which are confluent in the true whales.) It 

 may be presumed that the unfortunate animal had found its way 

 into the river but was unable to find its way out, and had so died 

 of hunger. The body must have finally grounded after long 

 drifting by wind and tide somewhere near the place where the 

 relics were discovered. For the bones which I examined, were 



