268 T. W. EDGE WORTH DAVID. 



It is expected that this bore may strike the productive coal- 

 in easures belonging to the Newcastle or Tomago Series at a depth 

 of approximately 2600 feet. The associated eruptive rocks of 

 this group have not yet been studied with the exception of the 

 cupriferous tuffs. These are evidently related to the copper 

 bearing andesites of Kiama. Possibly the volcanic eruptions, 

 which produced the older Kiama lavas were prolonged into early 

 Mesozoic time, or w r ere renewed then, and produced the cuprifer- 

 ous tuffs ; or the copper in the latter, supposing them to be 

 principally of detrital origin, may have been derived secondarily 

 from the Kiama andesites. 



Group IV. 

 Brown Coals. 



Brown Coals and Lignites are developed principally in the deep 

 leads of Tertiary age at Gulgong, Home Rule, Tingha, Forest 

 Reefs, Kiandra, etc. The Rev. W. B. Clarke also describes beds 

 of lignite at Chouta Bay, about 42 miles north of Cape Howe, 

 which he thinks may be of Tertiary age. The lignites are in 

 most cases capped by basalt. At Kiandra the lignite beds which 

 there overlie the gold gravel is as much as thirty feet thick, as 

 described by Mr. C. S. Wilkinson. These lignites contain too 

 much water to admit of them being advantageously used as fuel 

 at present. 



At the Morwell Mine in Victoria, however, lignite beds are at 

 present being worked for industrial purposes, and have been 

 proved according to the Reports by Mr. R. A. F. Murray, the 

 Government Geologist, and Mr. J. Stirling, f.g.s., to have a 

 thickness of from fifty to over one hundred feet. Possibly the 

 lignites on some of the deep leads of New South Wales may be 

 utilized when wood supplies become scarcer. 



The foregoing paper purports to be a rough sketch of the 

 author's present views of the Coal-measures of New South Wales 

 and their eruptive rocks. The whole subject will be treated of 

 at greater length it is hoped in the Memoir on the Coal-fields of 

 New South Wales, which is now being prepared by the Geological 

 Survey. The work of correlating these coal-fields is very far from 

 being completed at present, though year by year our knowledge 

 of them is being constantly increased by fresh observation. It is 

 chiefly to the Rev. W. B. Clarke that the credit belongs of the 

 provisional classification of our coal-fields, and it may truly be said 

 of his work that there has so far been nothing in it which we can 

 alter, and up to the present we have been able to add very little to it. 



In compiling the above paper I have also to acknowledge my 

 indebtedness to Messrs. C. S. Wilkinson, R. Etheridge, Junr., J. 

 Mackenzie, W. Keene, Stutchbury, Odenheimer, the Rev. J. 

 Milne Curran, f.g.s., the late Professor W. J. Stephens, f.g.s., 

 and my colleagues Messrs. W. Anderson, and G. A. Stonier. 



