BY H. I. JENSEN. 559 



SO much in this way to open up and make known the l^eauty 

 spots of New South Wales. 



Owing to the very characteristic physiography of the Warrum- 

 bungles, I published a preliminary note on that subject last 

 year.*t 



2. Petrography. 



The rocks of the Warrumbungle Mountains fall under the 

 headings Sedimentary, P5^roclastic, and Volcanic. 



The Sedimentary Rocks consist of sandstones, shales, calcareous 

 shales, conglomerates and recent alluvial. The Permo-Carbon- 

 iferous System (Upper Coal Measures) is met with in most places 

 E. and S.E. of the Warrumbungles, and consists of clay- 

 shales, coal seams, sandstones, and conglomerates, which have, as 

 a general rule, a dip to the S.W. of 1 in 20. Dolerite sheets or 

 sills of pre-Tertiary age occur in connection with these rocks. 

 In places we meet with mesas of sandstone of later (Triassic or 

 Trias- Jura) age dipping N.W., and capping the Permo-Carbon- 

 iferous, e.g., Mow Rock, etc.; and cappings of andesite and basalt 

 of Tertiary age are also common. 



In the Warrumbungles proper, to the north of them (in the 

 Pilliga Scrub), and north-east at Ulimambra we meet with sand- 

 stones and conglomerates which have, when not much disturbed 

 by igneous intrusions, a N.W. dip of 5°-10°. These rocks have 

 the usual barren look of Australian Triassic and Trias-Jura 



*These Proeeedings,»1906, p. 228. 



tSince the above was written the Government Geologist, Mr. E. F. 

 Pittman, A.R.S.M., has lately contributed a "Note on the Occurrence of 

 Precious Opal at Tooraweanah, Warrumbungle Mountains," and Mr. Henry 

 Deane, M, A., F.L.S., some " Notes on the Fossil Leaves from the Warrum- 

 bungle Mountains " to the last issue of the Records of the Geological Survey 

 of New South Wales (Vol. viii.. Part 3, 1907, pp. 187 and 189). 



Mr. Deane's investigations show conclusively that the trachytic eruptions 

 were of the early Tertiary age, for the tuffs in which the leaves examined by 

 Mr. Deane are found occur sometimes interbedded with trachytic flows, 

 sometimes overlying a trachyte flow and underlying a later basalt flow. 



Both the above papers bring corroborative evidence for conclusions which 

 I have come to in this paper. 

 44 



