THE PETROGRAPHY OF SOME QUEENSLAND 
OIL SHALES. 
By A. W. Beasley, M.Sc., 
Department of Geology, University of Queensland. 
(Plate XII and Two Text-figures.) 
CONTENTS. 
Introduction. 
Technique in Preparation of Thin Sections. 
Petrographic Descriptions. 
Alpha Torbanite. 
Carnarvon Creek Torbanite. 
The Narrows Oil Shale. 
Strathpine Oil Shale. 
Conclusion. 
Acknowledgments. 
Bibliography. 
INTRODUCTION. 
“An oil shale is a sapropelic shale rich in organic matter that yields 
considerable artificial petroleum by distillation’ 7 (Twenhofel, 1932, p. 397). 
Within this definition are included what McKee (1925, p. 27) has called the 
“true oil shales,” as well as the specialised group of algal sapropelic deposits 
known as the torbanites. 
In Queensland such oil shales have been recorded from the Permian, the 
Jurassic, and the Tertiary. In the Permian three deposits have so far been 
found — viz., the Alpha, Carnarvon Creek, and Bowen River Coalfield deposits. 
In the Jurassic small lenses of oil shale have been recorded from some of the 
Walloon coal-mining areas on the Darling Downs and in the Rosewood-Laidley 
district. Oil shales have also been recorded from several of the Tertiary basins 
in the eastern part of the State and, in some of these, the deposits are known 
to be quite extensive. 
No detailed petrographic description of any of these oil shales has 
previously been published. In fact, laboratory investigations in the past have 
been confined almost entirely to chemical analyses and distillation tests. This 
is unfortunate, for the petrological examination of an oil shale is equally as 
important as its chemical analysis, and is an essential requirement in its 
systematic study. The quality of an oil shale can, in fact, be determined from 
a study of its physical properties, since these depend upon the nature, 
percentages, and arrangement of the various organic and inorganic constituents. 
A microscopic examination, however, is necessary to determine this data, as well 
as to investigate the biological origin and the environmental conditions under 
which the oil shale was formed. 
