870 GEOLOr;V OF GLASS HOUSE MTS. AND DISTHICT, 



collected by Mr. J. M. Newman, B.E., at the Blacks' Reserve, 

 near Woodford. 



The country around Woodford is granitic. Mr. Newman 

 obtained specimens of granite (both coarse and fine), gneiss, 

 diorite, graphic granite, pegmatite (in veins), diorite, syenite and 

 basic rocks. A dyke of basic rock like hypersthene anorthite 

 ijabbro, and a dyke of hornblende andesite composed almost 

 wliolly of hornV)lende, also occur here, intruding the granite. 



vi. Other Australian Trachytes. 



Professor Gregor}^ has lately descri])ed an interesting series 

 of Geburite-Dacites and Trachy-Phonolites occurring at Mount 

 Macedon, Vic* They seem to have many features in common 

 with the rocks of the Glass House Mountains district. 



The rocks of the Warrumbungle Mountains are recorded as 

 trachytes by Profes>:or T. W. E. David, who obtained there not only 

 numerous specimens of trachytic lavas, but also tuffs interbedded 

 with the trachytic magmas. In Wantialable Creek they overlie and 

 are in part interbedded with diatomaceous earth and shales con- 

 taining Cinnamomum leaves. The entire group of the Warrum- 

 bungle Mountains is known, through Professor David's researches, 

 to form the wrecks of former trachyte volcanoes, and to consist 

 of coarsely crystalline trachytic rock and interbedded tuffs. I 



The trachytic heights of the Canobolas, near Orange, have 

 lately received a great deal of attention and patient investigation 

 by Messrs. Siissmilch and Curran, and it seems probable that these 

 will prove to correspond in age and particulars to the other Aus- 

 tralian Trachyte areas. 



In Tasmania rocks analogous to our Australian trachytes have 

 been discovered at Port Cygnet. They are chiefly Solvsbergites, 

 as are also some of the Mount Macedon rocks described by Prof. 

 Gregory, of Melbourne. No definite flows have, so far, been 



* Proc. Roy. Soc. Vic. Vol. xiv. (New Series), pp. 193, 197. 

 t "Note on the Occurrence of Diatomaceous Earth at the Warrumbungle 

 Monntains, N.S.W." Proc. Linn. Soc. N.S. Wales, 1896. 



