PRESIDENTIAL ADDRESS. 45 



latter district the trend is N. and S. (true). Trend lines 

 are also shown by the belt of serpentine to the west of 

 Gympie (about N. 10° W., true) and the immense mass of 

 serpentine to the north of Rockhampton. The latter trends 

 N.W. and S.E. true, and is evidently situated on a zone of 

 heavy fractures. These extend all the way from Gladstone 

 to Herbert Greek at Broadsound. The trachyte volcanic 

 centres of Yeppoon and Berserker Ranges are close to these 

 major lines of fracture. They are doubtless part of the 

 group of great fractures along which the former eastern 

 side of the Divide has been stepped down below sea-level. 

 There is both physiographic and stratigraphical evidence 

 for this fault at Curtis Island. 



Mr. Lionel V. Ball, b.e., 1 shows on map 11 of his instruc- 

 tive report, that there is a basin of Burrum Beds (Trias, 

 or Trias-Jura) thrown against Devonian rocks. The Boyne 

 River follows this line of fault, which, presumably throws 

 to E. 40° N. The channel between Curtis Island and the 

 mainland is on a continuation of this fracture. Beyond 

 Keppel Bay it seems to divide, an eastern branch going to 

 Shoalwater Bay and the Northumberland Islands, the 

 western to the estuary of Herbert Creek, at Broadsound. 

 Another profound fracture, observed by me in 1891, bounds 

 the Styx River Coal-field on the East. I estimate that it 

 has a throw of fully 3,000 feet. It is probably prolonged 

 to where on the chart of the Barrier Reef, north of Broad- 

 sound, the note occurs " it is unsafe to pass to the eastward 

 of this line." If so, this fault has a length of fully 250 

 miles. This trends in a S. by E. direction, striking for the 

 Dawson River to the east of Duaringa. Several important 

 faults have been recorded by Mr. B. Dunstan in this region. 



1 Geol. Surv. Queensland, Publication No. 194, "Certain iron ore, 

 manganese ore, and limestone deposits in the Central and Southern Dis- 

 tricts of Queensland." Brisbane, by authority, 1904. 



