44 T. W. E. DAVID. 



W.S.W. to E.N.E. The latter are in sympathy with the 

 Burdekin and Kimberley lines, and the former with those of 

 the Oape Gold-field and the New Caledonia to New Guinea 

 lines and the Charters Towers granite axis. 



Dr. R. L. Jack wrote me in 1894, " The folding of the 

 Gympie formation [Gympie here used in the sense of Pre- 

 Star (that is Pre- Upper or Middle Carboniferous) and Post 

 Burdekin (Post-Middle Devonian)— T.W.E.D.] must have 

 been the chief factor in the evolution of the eastern coast 

 range. That it took place before the deposition of the 

 Star formation I have little doubt in my mind, as the latter 

 though nowhere observed in contact with the Gympie, is 

 comparatively undisturbed." Dr. Jack would probably in 

 view of later palseontological determinations which show 

 that much of the Gympie beds are really newer than the 

 Star beds, and that the Gympie has certainly in places been 

 folded fairly strongly, see his way to modify this statement, 

 so that one might conclude that one of the chief factors in 

 the evolution of the Main Divide has been the folding of 

 the Carboniferous and Permo-Carboniferous rocks along 

 lines mostly coincident with the long axes of the granite 

 batholiths. Trend lines are also indicated in the Main 

 Divide unit by the general distribution of the main basalt 

 flows and volcanic foci. Notably to the east of Clermont 

 these foci are grouped along N. 40° W. and S. 30° E. lines. 



Dr. H. I. Jensen 1 has indicated the trend lines of the foci 

 and general zone of the alkaline lavas in the Mount Flinders 

 and Fassifern districts and the east Moreton and Wide Bay 

 districts. In the former district the zone trends about 

 N.E. and S.W. (true), but the local groups of volcanic foci 

 appear to trend about N. 15° W. to S. 15° E. (true). In the 



1 Proc. Linn. Soc. N. S. Wales, 1903, pt. 4, ap. 842-875, pis. xlvi-lj 

 ibid., 1906, pt. 1, pp. 73-173, pis. v, vbis-xvi; ibid., 1908, Vol. xxxiii, 

 pt. 3, pp. 491 - 588, especially p. 585 ; ibid, 1909, Vol. xxxiv, pt. 1, pp. 67 

 - 104, pis. i- vi. 



