PRESIDENTIAL ADDRESS. 35 



strata are not repeated by isoclinal folding and faulting, 

 nearly 10,000 feet of red sandstones and shales are there 

 developed lying in a trough, the axis of which trends nearly 

 N. and S. from a little W. of Wellington towards Molong. 

 Mr. Siissmilch 1 has already called attention to the strong 

 disturbances of the nature of recent faulting, determined 

 on physiographic evidence, extending from Jindabyne and 

 Oooma, in the former case north-easterly, in the latter 

 northerly. The Oooma-Oolinton line of fractures is 

 parallel to the upper course of the Murrumbidgee, that is 

 about N. 5° W. Mr. T. G. Taylor has further examined 

 the zone of faults between Lake George and the Murrum- 

 bidgee River near the site of the Federal Capital at 

 Canberra. In his latest work he refers to this Snowy- 

 Murrumbidgee line of disturbances as a rift valley running 

 northwards to the volcanic region of the Canobolas, and 

 thence by way of Wellington to the volcanic zone of the 

 Warrumbungle volcanic necks. These faults, described by 

 Siissmilch and Taylor, are of course recent faults for the 

 most part belonging to the present cycle of erosion, but 

 they appear to be established along old lines of intense 

 folding and major faulting. It is much to be desired that 

 a reliable cross section of this beautiful tectonic region 

 between Bathurst and Parkes be obtained by actual survey. 

 An important fact to be noted in the Bathurst-Monaro 

 tableland lying to the south of the great central coal-basin, 

 is that along its north-eastern margin is an extensive belt 

 of Devonian rocks which strike nearly conformably with 

 the axis of the main trough of the great coalfield. One 

 would expect to find the overfolds of the Devonian rocks 

 directed here towards the main axis of subsidence ; on the 

 whole, though the dips are often reversed in the neighbour- 

 hood of axes of intrusive masses of granite, the marginal 



1 This Society's Journal, Vol. xliii, pp. 331 - 354, pis. ix - xiii. 



