In tlie Queensland area we have evidence of similar accumulations of carbonaceous shales, 
though 1 doubt if we have evidence of such settled conditions of deposition. The nature of 
the beds suggests fairly shallow water conditions throughout. We certainly have no evidence 
of a proved oil-bearing series beneath from which migration may have taken place. However, 
coals and a good development of carbonaceous shales do exist, and it becomes a question as to 
whether such beds can have been the source of sufficient bodies of oil as to be payable to work. 
If oil has originated in such quantities, are the structural conditions so satisfactory that the oil 
so formed may have accumulated in commercial quantities ? This is another question which is 
difficult to answer. While I have suggested that such structures may exist, they require to be 
proved by much more detailed geological work than has been done up to the present time. It 
has been suggested that such structures may have to be proved by putting down a number of 
shallow or deep bores. Where strata are so lenticular, thinning and thickening from place to 
place, the results obtained by such boring may be very misleading. A structure which may 
appear to be that of a dome may turn out to be only a lense of sandstone or shale. A reference 
to the vertical sections of the three bores put down close together at Roma, shown in Mr. Cameron's 
work mentioned below, shows not only the lenticular nature of the strata below ground, but changes 
over short distances that must be regarded as astonishing. It is necessary, therefore, to know 
just how persistent beds are, and detailed geological survey work will throw much light upon this 
as well as upon the finer structural features present in the area. 
F. Sub-Surface Evidences. 
Turning now from the argument which has been developed from the evidences presented 
at the surface, and dealing with conditions as they exist underground, we find that interest has 
always centred upon the results obtained by the series of deep bores put down at Roma. These 
results have been clearly set out and ably discussed by Mr. Cameron, formerly an officer of the 
Geological Survey in Queensland, and in this discussion several of the world’s leading oil experts 
took part.* 
Four wells were drilled at Roma between 1897 and 1922. All are situated within a 
comparatively small area (less than 2 acres, I should judge) of rising ground immediately to the 
west of the town and about 1,020 feet above sea level. Roma is situated a few miles to the south 
of the southern limit of the exposed Walloon belt, and is, therefore, on the Marine Cretaceous 
which overlies the Walloon strata with apparent conformity. Where the bores are situated, 
the Walloon strata are about 300 feet below the surface and the general dip to the south is very 
low, apparently not much greater than 2°. The first well was put down for water in 1897 only 
to 1,678 feet, so that no showings of gas are recorded in connexion with it. The other three all 
reached about the same depth, varying only between 3,709 and 3,713 feet. Each of the bores 
passed through alternations of sandstones and shales, considerable thicknesses of the latter being 
dark and carbonaceous. A 4-ft. seam of coal was met with at about 700 feet in the first two bores, 
but had apparently petered out in the third bore, which only records streaks of coal at this horizon. 
A number of coal seams were again met with between about 1,900 feet and 2,400 feet, but if the 
bore logs were at all accurately kept the variations in the strata, at points only 240 feet apart 
as these bores were, are really remarkable, and only confirm my opinion as to the danger that 
would be involved in attempting to locate structural conditions by means of shallow bores. No 
horizon at all is revealed in the bore logs that can be called consistent, every stratum showing si« ns 
of very marked lenticularity. Natural gas, accompanied by fresh water, was met with in the 
shales which form the basal beds of each of the deeper bores, but there seems to be some doubt 
as to the exact horizon from which it came as well as uncertainty as to whether the water is present 
in the strata along with the gas or whether it broke through from some other source. The best 
flow of gas was encountered in bore No. 3 at 3,702 feet. Mr. Henderson, the Government Analyst 
tells me that at the time of his inspection he estimates the flow to have been in the neighbourhood 
of 10,000,000 cubic feet per day. In this connexion a few paragraphs should be quoted from the 
report of the Advisory Committee on the Development of the Gas Field at Roma. These paragraphs 
are of great importance, and combine much wisdom with caution. The Advisory Committee 
consisted of Messrs. W. E. Cameron, late Deputy Chief Government Geologist; J. B. Henderson 
Government Analyst; and Arthur Moore, Officer in Charge of Drilling Operations. 
Yield of Gas. 
Paragraph 4. — In spite of the obstruction in the 8-in. bore, the yield of gas running free was enormous, certainly 
many millions of cubic feet per day. Owing to the presence of water with the gas, and there being no separator availa ble 
it was not possible to measure the flow of gas. 
Petrol Content: of Gas. 
Paragraph 5. — Under adverse conditions both of temperature and pressure a yield of 1‘2 units of petrol per 1 00(1 
cubic feet was obtained. As this petrol contained no pentane and very little hexane (which constitute the lighter portion 
of petrol) it is almost certain that these constituents, when recovered with the others, will materially "increase the 
yield and value of the petrol from the gas. 
* Cameron, W. E.. B.A. Petroleum and jS’afursU Gas Prospects at Roma, 
for Development, by Sir Roverton Redwood 
W. H. Dalton, F.G.S., F.C.S., Lionel C. Rail 
and Natural Gas Prospects at Roma. Also Reports and Correspondence on Prospects for iwmi,..,™ 
Bart., Sir Thomas Robinson , K.C.M.G., Dr. A. 0. Veatch, Win. Hope Henderson, M I M M ft 
. R.A., B.F. (Syd b— Q.G.S. publication No. 247. ’ ' Gbarteris, A. Stewart 
