CHAPTER LXXX 



* 

 THE AUTHOR'S EXPLORATIONS, 1879-80, continued 



AN AFTERWORD 



GEOLOGICAL CONSIDERATIONS. HORIZONTAL SANDSTONES OF DIFFERENT AGES IN 

 CONTACT. EMERGENCE OF PALEOZOIC ROCKS FROM BENEATH SANDSTONES AT 

 VARIOUS POINTS NEAR CAPE YORK. THE EXPEDITION HELPED TO GUIDE LATER 

 PROSPECTORS. 



THE "simplicity" of the geological structure of the Cape 

 York Peninsula is possibly more apparent than real. 

 Subsequent observations, and especially those made in 

 1902 by Mr. C. F. V. Jackson, of the Geological Survey, 

 lead me to suspect that there may be a mixture of sandstones of 

 Carboniferous with others of Cretaceous age. One bed of horizontal 

 siliceous sandstone is very like another, and in some instances I 

 may have assumed continuity where there was only juxtaposition, 

 and faulting may have placed beds of similar composition and 

 appearance together. The complex structure of " The Brothers " 

 and the " Little (Kennedy) River," near Cooktown, may be repeated 

 further to the north, and detailed geological surveying in the 

 future may yet reveal distinctions unsuspected by me in the year 

 1880. The fact, however, remains indisputable that the great 

 bulk of the northern part of the Peninsula is covered by arenaceous 

 sedimentary rocks, whatever their age may be. 



My observations at Cape York ended with the arrival of the 

 party at Somerset, as my physical condition, following on my 

 wound, imperatively demanded rest. Otherwise I might have 

 learned that no more than 6 miles to the west, in the low " Carnegie 

 range," as well as at Cape York, at Peak Point and in Possession 

 Island, Palaeozoic rocks, potentially auriferous, emerge from 

 beneath horizontal sandstones of a later age. 



As will appear from subsequent chapters, I am justified in 

 believing that my reports on the " First " and " Second " Expedi- 

 tions helped to guide a generation of hardy and persevering pros- 

 pectors to discoveries of gold and other metals as far to the north 

 as Temple Bay. There is no reason to suppose that the record 

 of progress is closed. 



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