14 
oil whatever. It is so easy for a little oil to get into the boring from drilling line, casing joints, 
drilling tools, &c.,that such small showings must be regarded with suspicion, especially where 
the drilling is in the comparatively loose barren and water-logged sands of the Post-Tertiary 
deposits. Lower down in the bores where carbonaceous matter and thin coal seams are encountered 
it is possible that very small amounts of oil are present in the strata, and some of the showings 
certainly suggest this. For example : Mr. Ball states that a sample sent in by Mr. Campbell 
was found by the Government Analyst to contain 2.3 per cent, of free oil, pale-vellow in colour, 
and having the consistency of mineral grease at 20°C. This suggests vaseline-like derivations 
from the coaly matter present such as is sometimes found near where such beds have been intruded 
by igneous rocks. While the Mesozoic strata have been intruded in the neighbourhood of the bore 
sites, the nearest observed intrusion is at least 10 miles distant, which is too far away to produce 
such direct results ; on the other hand, areas of intrusion, concealed under the recent sandy 
covering, may occur in much closer proximity to the bore sites. Analyses show that the thin 
coaly seams present have undergone considerable metamorphism. The coaly scum from 497 
feet, which gave 0.21 per cent, of free oil (see log quoted above), was obtained not far below the 
sample which gave 2.3 per cent, free oil. Both oils had the consistency of mineral grease at* 20°C. 
The Government Analyst separated the coaly particles and air dried them before submitting them 
to analysis. They showed a fixed carbon-ratio of 80. Other samples of coal from 673 feet and 
677 feet respectively gave carbon-ratios of 70 and 64.6 respectively, the average being 71.5, which 
is very high, and well beyond the limit of metamorphism for possible supplies of oil in 
commercial quantities. The carbon-ratio theory is only intended to apply to clean, bright, 
unweathered coals. Any attempt to use carbonaceous shales and dirty or weathered coals can 
only result in percentages which are very misleading. The percentage of ash is normally much 
higher in carbonaceous shales than in coals, so it is obvious that the figures given by Fuller cannot 
possibly apply to the case of shales. Moreover, as Mr. F. E. Connah, one of the Government 
Analyst's stall’, points out to Mr. Ball,* the figures given for volatile matter in the analyses made 
of shales and dirty coals may include water of combination from the inorganic ground mass present, 
which again would vitiate results. Mr. Ball* very rightly draws attention to this with regard to 
analyses of coals obtained from similar beds in an old colliery at Weyba, near Tewantin, and at 
a depth of 345 feet in borehole I N, which give carbon-ratios of 48 and 46 respectively. Both 
results are obviously quite contradictory when compared with those obtained from clean samples 
as quoted above, which are in fair agreement when the nature of the materials submitted to analysis 
is taken into consideration. In any case they are too low to be of any value. 
In conclusion, 1 must state that I do not consider that- the presence of such small quantities 
of oil in these beds is of value in indicating the existence of commercial supplies of oil. Boring 
for oil in such circumstances is rank wild-catting. Now, wild-catting has played an important 
part in oilfield development, especially in known oil-producing regions and where structural features 
have been taken into account in the location of wells. Most of the successful wild-cat wells in 
Texas, Oklahoma, Arkansas, and Louisiana have been well situated on geologically located 
structures. Although oil-bearing strata have not been previously proved to underlie such 
structures, the general knowledge obtained from a geological study of the surrounding regions 
has shown that such oil-bearing strata may or should exist ; on the other hand, not all wild-cat 
wells so located are successful, and many fine structures have been drilled deeply into water 
sands. 
In this Laguna Beach district such structures as may exist in the Mesozoic beds, which 
have given the best evidences of oil, are concealed under a surface cover of recent sandy deposits 
so that they can neither be located not studied at the surface. On general evidence the area 
is probably one of depression. While it is not my wish to discourage prospectors, T would suggest 
that there are, in Queensland, areas which are more worthy of attention. Long experience in 
oilfield practice has made it quite clear that no successful oil-producing company will drill on 
any area unless and until the geological structure is clearly defined and proved as nearly as possible 
to be favorable. Once again I should like to point out that the object of the search is not for 
small showing's of oil — the so-called encouraging signs — but for commercial supplies, something 
that can be worked profitably not only for the prospecting company but for the State and for the 
Commonwealth of Australia itself. It is therefore of the utmost importance that attention should 
be directed towards and effort concentrated upon such areas as may exist where suitable types of 
sedimentary deposits have been laid down under suitable conditions ; where subsequent folding 
of these deposits has developed in them suitable structui'es beneath which oil can have and may 
have accumulated ; where igneous intrusives and other agencies of metamorphism have not so 
changed the nature of the original sediments as to give us coal seams with unduly high ratios of 
fixed carbon, and where all these things can, in the first instance, be studied directly at the surface 
and not inferred or guessed at. If such concentration of attention and effort should eventually 
* Loo. dt. p, 357. 
