L3 
feet of rock as compared with the Newcastle series.”* Much of this was removed from the central 
part of the Lochinvar area before the deposition of the Triassic rocks, but there is also proof that 
metamorphism had gone so far as to change the carbonaceous deposits into true coals before 
this denudation had taken place and the Triassic sediments were laid down.f Moreover, the. 
Greta coal seams that are now being worked occur well down on the flanks of the Lochinvar uplift. 
The denudation which took place between Pernio-Carboniferous and Triassic times was most 
severe along the axis of maximum uplift, and the amount of cover which was removed must 
have diminished considerably as we proceed in any direction away from this axis. 
However, we have still to account for the fact that the carbon ratios of the Greta coals 
are lower than those of the Upper Coal Measures, whereas they should apparently be higher. 
In studying this problem it occurred to me that the carbon ratio theorists had probably been 
dealing with coals of pretty uniform types of origin, and that there may be other types of coal 
which did not conform to the theory.' I therefore set out to see whether there was any reason 
to suppose that the Greta coal had a different type of origin from the coals above. I first found 
that it was closelv associated with bands of cannel coal and kerosene shale, and that the seams 
of bituminous coal contained patches where such coals passed gradually into kersoene shale. 
1 had already drawn attention to the fact that carbon ratios should not be taken from oil shales 
or impure coals in mv Queensland report, J since they tended to give carbon ratios which weie 
much lower than those of true coals in the same areas. Professor David, who has studied tins 
area more thoroughly than any other person, throws some light on the subject. He states :§ " As 
regards their mode of origin, the Greta coals do not exhibit roots of \ ertebraria, as fai as has been 
observed, in their underclavs, nor indeed any kind of roots except perhaps very fine rootlets. 
From the fact that marine beds occur close underneath them as well as close above, and from the 
general absence of fossil wood from the seams, it has been suggested that they are of algal origin. 
This, however, is not borne out by the presence of Gangamopteris together with Noeggerathiopsis 
and Glossopteris leaves occurring in the clay bands of the seams. It seems more probable that 
while the climate was yet too cold for the development of large trees the seams were formed m 
the positions where we now find them, but out of lowly peaty growths somewhat analagous to 
those which have been recorded bv Sir Douglas Mawson and others on sub- Antarctic Islands, such as 
Macquarie Island, Campbell Island, &c.”|| He also states^ that at the old Homeville mine near 
Farley. “ the Greta Coal Measures embrace five seams varying in thickness from z feet up to 
5 ft. 7 in., and containing an aggregate of 17 ft. 9 in. of coal. The middle seam, 4 feet in thickness, 
is a cannel coal, which under the microscope in thin sections seemed to be formed largely ot the 
translucent yellow bodies named by Bertrand and Renault Reinschia australis and referred to by 
them as an alga. In places, lenticular patches up to 10 inches in thickness of kerosene shale 
have been found in the Greta coal seams and at Greta itself." Elsewhere, he says, that * In 
places, on account of the gradually increasing proportion of the fossil known as Reinsckia australis 
in the coal, the coal passes over into cannel coal, and at places into kerosene shale. 
I had reached this stage in the preparation of this Report when Professor E. W. ^keats. 
of the Melbourne University, knowing that. I was studying this problem of carbon ratios m relation 
to the Greta coals, drew my attention to a paper in the last issue of Economic Geology -which 
had reached this oountrv.fi* It is written by an American investigator, Mr. William L. Russell, 
who has found very similar conditions in oil-field regions m Kentucky. Since, in my opinion, 
the conclusions arrived at in this paper clear up the whole problem very much on the same hues 
as those upon which 1 have been working, 1 shall take the liberty ot quoting .roin it lathei 
extensively. 
Speaking of his area, Mr. Russell states that 
The ordinary bituminous coals were formed in swamps and are composed chiefly of woody fibres and similar 
materials. The cannels, on the other hand, were formed in lakes and other bodies of water and are composed d 
of the remains of spores, pollen, and the like. Of course, all gradations between these two types o cur and urthcrnio, v 
the bituminous coals contain some canneloid matter, the amount of which vanes irregular}. . -> 
81119(11 spams of cannel coal arc embedded, with the bituminous niattei. . . . • u 
The cLd coals run higher in volatile matter and lower m fixed carbon than the bituminous coate, as m well 
known. Though the percentage of fixed carbon (moisture and ash free) averages roughly 10 per cent, lower 11 . n 
cannels, the actual amounts vary greatly, ranging from a few percent to 20 per cent, lower It does not s ;PP^r pos^h K 
in this region to obtain the regional fixed carbon content of the bituminous coals by adding an> _dehmte Amount to 
that of the cannel coals. About all that can be said is that the average fixed carbon content of the bituminous coals 
is much higher. 
* Mem. Geol. Surv., N.S.W. - Geol. No. 4, p. 329. 
•jr Mem. Geol. Surv., X.S.W. — -Geol. No. 4. pp. 333 and 339. 
j kemene shale. Tfe Tcmago and Newcastle Coal Measures, as a 
rule do not contain llrimchta to any appreciable extent.” 
’ 1| Guide Book, Ac., already referred to, pp, 29 and 30. 
;; ^Ho G nte& i» Kentucky. -Been. Geol., Vo.. XX., Xo. 3, May, 1*5, PP. »» 
