378 PHYSICAL STRUCTURE AXD GEOLOGY OF AUSTRALIA, 



hardened cores of aerial accumulations. The stratification is 

 entirely that of wind-blown rocks with ferruginous bands, which 

 are the remains of surface vegetation, from which the carbonized 

 roots of trees may often be seen depending. Unless by the 

 included organic remains, and superposition, we have no means 

 of determining what is the age of these beds. But it would be 

 wrong to attribute them all to one period. Similar conditions 

 would produce the same kind of rock in any epoch. 



In jS^ew South Wales such beds lie upon the coal beds (Permian 

 and Lias) but not always conformabl}^ In Queensland they lie 

 upon the Cretaceous, and are clearly tertiary. It would be very 

 difficult, indeed, to draw any line of distinction between the 

 Queensland Sandstones, and those of Xew South Wales or 

 Hawkesbury Sandstones as far as lithological character is con- 

 cerned, and the included plant remains are common to both. 

 But in portions of the Hawkesbury Sandstone, fossil ganoid 

 fishes of the genera GleithroJejjis and 3I//rioIrpls hvq found, which 

 have strong resemblances (as far as imperfect specimens would 

 admit of a comparison) to Devoninn forms. In beds above the 

 coal bearing strata termed Wiannamatta, the Permian genus 

 Palceouiscus is found. Xevertheless it would be absurd to consider 

 the Hawkesbury Sandstone as of Paleozoic or even lower Mesozoic 

 age. The anomaly of the fish remains, we must explain, by 

 recalling that we have amongst us two species of the Liassic 

 andTriassic genus Cer«fo(/«^5, actually living in Queensland rivers. 

 Throughout Australia, therefore, we may consider that in desert 

 or sandy regions an eolian or aerial deposit has formed or is 

 forming. It hardens into stone in certain portions, and thus 

 gives rise to tlie ])reeipitous sandstone cliffs and flat-topped 

 mountains wliicli are so cliaracteristic of Australian scenery. 

 These formations are mentioned in this place because there is a 

 complete blank between them and the lower Mesozoic rocks in 

 most places in the colonies. Nevertheless we have some missing 

 links of the secondary deposits now to be specified. 



