120 The N.Z. Journal of Science and Technology. [Mar. 
prospecting license by the Waikaia Oil-shale Development Company. I also 
made some geological observations in the neighbourhood of Waikaia. 
The Waikaia Oil-shale Development Company is at present putting down 
a series of bores with the aid of a Government drill in Block I, Wendon 
district, not far to the north-west of Freshford Railway-station. Mr. W. H. 
Warburton is in charge of the drill, and Mr. Fred. Hamer is manager for 
the company. At the time of my visit seven bores had been drilled with 
varying success, and an eighth was under way. 
Until the boring is finished the area and quantity of oil-shale cannot be 
accurately estimated, but it appears that workable shale is confined to an 
area not much if at all exceeding 40 acres. The thickness of shale proved 
by boring is from 6 ft. to 10 ft., but that part of the seam worked a number 
of years ago as the Muddy Terrace Coal-mine in order to supply fuel to 
dredges was from 14 ft. to 17 ft. thick, and, as is shown by analyses, was 
of higher quality than that now being tested. It may be added that bores 
drilled a few years ago proved a few acres of thick shale, very probably of 
quality similar to that mined for use as fuel. 
Quality of Oil-shale .—The Waikaia oil-shale is similar in composition to 
the Orepuki, Roxburgh, and Cambrian oil-shale. In 1907 a sample for¬ 
warded by the Round Hill Mining Company, probably taken from the 
workings of the Muddy Terrace Coal-mine, was analysed at the Dominion 
Laboratory and shown to be of very high quality, the yield of oil being 
30-1 per cent., equal to 67-4 gallons per ton ( 41st Ann. Re'p. Dow. Lab., 
1908, p. 13). In 1914 I visited the locality and took a sample of shale 
from the opencast workings of the Muddy Terrace Mine, which yielded 
approximately 60 gallons of. crude oil per ton. The paraffin-content was 
equivalent to no less than 80 lb. per ton of shale. Sulphur was somewhat 
high—2-57 per cent. A sample of shale from No. 1 bore of the Waikaia 
Oil-shale Development Company was tested at the Dominion Laboratory a 
few months ago, with the result that it yielded only 30 gallons of crude oil 
per ton, containing paraffin equivalent to 35 lb. per ton of shale. Sulphur 
was 3T4 per cent. Samples from other bores have lately been forwarded 
to the Dominion Laboratory, and are now being analysed. 
It is clear that the thickest and best shale is near the outcrop on the 
eastern slope of Muddy Terrace, where it was worked as a source of fuel. 
It is much to be regretted that at least 18,636 tons (the recorded output) 
of high-class shale was wasted in this way, whilst in addition many thou¬ 
sand tons have probably been rendered unextractable. Some of the shale 
near the outcrop may be worked opencast, but elsewhere it is doubtful if 
as much as one-half or even one-third of the shale can be profitably mined. 
Moreover, it does not appear that the quantity of mineable shale would 
justify the erection of a treatment plant. If, however, the oil-shale works 
at Orepuki were restarted, the better-class shale could be railed to those 
works, and there treated for its valuable oil and paraffin contents. The 
distance by rail from Waikaia to Orepuki is ninety-nine miles, and the cost 
of haulage for this distance will probably prevent the lower-grade Waikaia 
shale from being sent to Orepuki. 
In future, mining of the Waikaia or similar shales for use as fuel alone 
ought to be prohibited. Any shale that will burn like coal is much more 
valuable for its gas, oil, and paraffin contents. 
In conclusion, it may be pointed out that, although the Waikaia shale- 
patch is small, similar patches may be found by boring here and in other 
parts of Southland. 
