194 SIR. T. W. E. DATED OX 



EVLDEXCE OE GLACIAL ACTIOX 



1. Disrupted Angular Fragments 

 of Shale. ■ 



The first mention of evidence 

 of ice-action in New South AY ales 

 was made by alt. Wilkinson, in 

 connexion with certain appear- 

 ances in the shale beds interstra- 

 tified with the sandstones of the 

 Hawkesbury series, in a paper 

 read before the Royal Society of 

 ]S"ew South Wales, December 4, 

 1879 (see Transactions of the 

 Eoyal Society of Xew South Wales, 

 vol. xiii. p. 106, 1880.) 



He makes the following state- 

 ment : — " In the sections exposed 

 in the quarries at Fort ITacquarie, 

 Woolloomooloo, Flagstaff Hill, and 

 other places, may be seen angular 

 boulders of the shale of all sizes 

 up to 20 feet in diameter, em- 

 bedded in the sandstone in a most 

 confused manner, some of them 

 standing on end as regards their 

 stratification, and others inclined 

 at all angles. They contain the 

 same fossil plants that are found 

 in the beds of shale from which 

 they have evidently been derived. 

 These angular boulders occur 

 nearly always immediately above 

 the shale beds, and are mixed with 

 very rounded pebbles of quartz ; 

 they are sometimes slightly curved 

 as though they had been bent 

 whilst in a semi-plastic condition, 

 and the shale beds occasionally 

 terminate abruptly, as though 

 broken off. Had the boulders of 

 soft shale been deposited in their 

 present position by running water 

 alone, their form would have been 

 rounded instead of angular. It 

 would appear that the shale beds 

 must have been partly disturbed 

 by some such agency as that of 

 moving ice, the displaced frag- 

 ments of shale becoming com- 

 mingled with the sand and rolled 

 pebbles carried along by the cur- 



