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MEMOIRS OF TEE QUEENSLAND MUSEUM. 
Within the clay matrix numerous small grains of quartz were recognised. 
They have not been affected by the yellowish stain, and appear clear and white 
under ordinary transmitted light. Pyrites is relatively abundant in the rock, 
occurring both as minute crystals scattered through the matrix and also as 
fairly large crystals aggregates. Its presence indicates that the original organic 
ooze was a strongly reducing medium, analogous to the fetid sapropels described 
from certain modern lakes. 
In the vertical section the parallel orientation of the organic masses and 
the inorganic constitutents in the rock is evident. 
From the large amount of mineral matter and the small amount of 
organic matter seen to be present it is clear that the oil shale is a low-grade one. 
Chemical Analysis. 
A proximate analysis of this sample has given the following result: — 
Moisture at 105 deg. C. 
Volatile Matter 
Fixed Carbon 
Ash 
4-8% 
29-1 % 
3-3 % 
62-8 % 
Chemically this indicates a low-grade oil shale. The low percentage of 
volatiles is determined by the small amount of organic matter present, while 
the high ash content reflects the large amount of mineral matter in the oil shale. 
STRATHPINE OIL SHALE. 
General and Macroscopic. 
Locality of sample chosen for study: From 70 ft. in Neill’s Shaft, 
Strathpine. Portion 256, parish of Warner, county of Stanley, approximately 
14 miles north of Brisbane. Geological Horizon : Petrie Series. Age : Probably 
Miocene. 
In the hand specimen this is a very fine-grained, smooth, even-textured, 
laminated rock of light brownish-grey colour. It has a dull lustre and breaks 
with a hackly fracture. It is soft but moderately tough, and gives a greasy 
brown streak. The specific gravity is 1-53. Thin flakes of the rock ignite with 
difficulty and burn for a short time with a smoky yellow flame. 
From the above description it is apparent that the rock is a low-grade 
oil shale. 
The presence of mud infillings of the internal cavity of fossil sedges 
protruding upwards across the laminations of the shale points to shallow water 
conditions of sedimentation. 
Microscopic. 
In thin section this rock is seen to be made up principally of very finely- 
divided clay, with a smaller amount of organic material. The clay is intimately 
associated with some of the organic matter, and under ordinary transmitted 
