Page:Northmost Australia volume 2.djvu/279

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616
NORTHMOST AUSTRALIA


in which the " Desert Sandstone " was deposited. In all probability the granite stood up as ranges prior to the deposition of the Desert Sandstone by virtue of its superior hardness to the surrounding unaltered slate and greywacke rocks. When subsequently a sub- mergence took place, the unaltered rocks, having been previously denuded into lowlands, were covered over by the Desert Sandstone. To one travelling northward from the Coleman River, the sandstone first appears far to the west, but it gradually steals eastward, lapping round the base of the range till it reaches the eastern sea-board at Temple Bay.

The sandstone has a very gentle dip to the west and north, away from the granite so gentle that there seems no reason to ascribe it to unequal upheaval, since the gradual deepening of the bottom on which the sandstone was deposited, as it receded from the land, is quite sufficient to account for it. This gentle dip coincides, or nearly coincides, with the fall of the ground from the ranges to the Gulf, while the Wilkinson, Geikie, Sir William Thomson and Richardson " Ranges " are the eastern escarpments of massive sandstone beds [or shelves].

The question of the geological age of the Desert Sandstone, which Daintree justly characterised as " the most wide-spread sedimentary formation in Queensland," is a very puzzling one, and much apparently contradictory evidence has been brought forward on the point. I hope to discuss the whole question shortly in the pages of a scientific journal. At present I shall only state my belief that the formation is homotaxial with the European Cretaceous rocks.

There is every reason to believe that the auriferous slates, etc., of the Palmer district are represented in the Peninsula further north, and may yet give up their wealth, but they are covered with such a thickness of " Desert Sandstone " as practically puts them beyond our reach for the present age. The granitic rocks forming the nuclei of the ranges, especially of the Mclvor and Mcllwraith Ranges, are to some extent auriferous, although apparently not sufficiently so to pay for European labour under the present con- ditions. My impression was that the " South Coen " (or Kendall ?) and the Peach could be at least worked with profit by Chinamen. Since the date of our visit to these rivers, however, the South Coen has been " rushed " by Chinese, who have returned disappointed, owing, it is said, to the expense of land carriage and the hostility of the blacks ; they never reached the Peach.

It is much to be regretted that the Peach was not more exhaustively prospected. The expedition started at the worst possible time of the year. Only a very hurried examination had been made when the floods came and rendered prospecting in the bed of such a river an impossibility. We travelled northward in the hope of finding payable gold elsewhere, and with the intention