104 W. G. WOOLNOUGH. 



horizontality of the strata, the amount of recrystallization 

 of the finer sediments is really remarkable. A very careful 

 search for fossils has not, so far, revealed any trace of 

 organic remains. Many estuarine deposits are singularly 

 barren of fossils, as, for instance, the Hawkesbury Series 

 of New South Wales, so that the absence of such remains 

 cannot be taken as certain proof of great age. The absence 

 of fossils is nevertheless remarkable if the beds are as 

 recent as Palaeozoic. It has been shown above that granite 

 has intruded the Stirling Range Series at the western end 

 of the area, so that the granite is very definitely the younger 

 formation. So far as the author has been able to ascertain 

 by reference to the literature, and from personal enquiries 

 and investigations, there is no record, within the western 

 half of Australia, of injection of granites into formations 

 whose age can be referred with certainty to any portion of 

 the Lower Palaeozoic. Pre-Cambrian granites occur over 

 enormous areas and are injected very freely into the later 

 members of the Pre-Oambrian sedimentary formations, for 

 instance into the Barossian Series of the Mount Lofty 

 Range of South Australia, the schistose rocks of Yorke's 

 Peninsula, the metalliferous slates and schists of the 

 Northern Territory, and the Warrawoona and Mosquito 

 Creek Series of northern Western Australia. On the other 

 hand in the Lower Cambrian Katherine River Series of the 

 Northern Territory, the Lower Cambrian beds of the Kim- 

 berly Division of Western Australia, and the Nullagine 

 Series of the Pilbara Goldfield of Western Australia granitic 

 intrusions are conspicuous by their absence. The age of 

 the Nullagine Series is undetermined through lack of fossil 

 evidence, but there is strong presumption that it is not 

 later than Devonian nor older than Cambrian, so that, so 

 far as it goes, the evidence is concordant. 



With considerable hesitation I therefore suggest, as a 

 tentative generalisation, the probability of the Pre-Cam- 



