Section C. ' 

 GEOLOGY AND PALiEONTOLO 



President of the Section : 



T. W. EDGEWORTH DAVID, B.A., F.G.S., Profpssor of Geology mid 

 Physical Geography, University of Sydney, N.S. W. 



1.— NOTES ON A CARBONACEOUS DEPOSIT IN SILU- 

 RIAN STRATA AT BEACONSFIELD, TASMANIA. 



By A. MONTGOMERY, M.A., Government Geologist, and W. F. WARD, 

 A.R.S.M., Government Analyst of Tasmania. 



(Plan and Section.) 



We have the honour to bring under the notice of the Section 

 the occurrence under unusual circumstances of a carbonaceous 

 deposit in the Beaconsfield Goldfield, in strata of Lower 

 Silurian or perhaps Cambrian Age. Lest the title of our paper 

 should be misleading, we may at once say that the substance 

 itself is probably not older than the Tertiary, being lignite or 

 closely allied thereto, and that the interest attaching to iti 

 that of the fly in amber — we wonder how it got there. The 

 peculiarity of the occurrence is that a lignite should be found 

 in the heart of a hill composed solely of very ancient grits 

 and sandstones. When first discovered, and previous to its 

 being analysed, the most hkely theory of its origin seemed to 

 be that it was derived from vegetable matter laid down 

 among the sediments, which afterwards became hardened 

 into grits and sandstones ; that it was, in short, a Silurian 

 coal. This erroneous idea was at once dispelled when 

 analysis proved that it had the same composition as many 

 lignites, and, as all well-established facts as to the origin of 

 coal are against the possibility of a lignite existing in strata 

 of such immense age, another explanation had to be looked 

 for to account for it. This, we think, we have been able to 

 find satisfactorily ; and, though the deposit does not possess 

 the great interest that would attach to it if it had been in 

 very truth a Silurian coal, however impure, yet it shows an 

 unexpected mode of occurrence of carbonaceous matter that 

 is worthy of notice, particularly on account of the proof that 

 it affords of the occasional presence at considerable depths 



