484 NOTE ON THE ORIGIN OF "KEROSENE SHALE," 



The kerosene shale at each of these localities is believed by 

 Mr. C. S. Wilkinson, F.G.S., the Director of the Geological 

 Survey, to occur in the Lower Productive Coal Measures, other- 

 wise known as the Greta Series, of Permo-Carboniferous age, and 

 this fact first recognised by Mr. Wilkinson may prove a valuable 

 help in the correlation of the different Coal-fields of New South 

 Wales. 



Occurrence. — Kerosene shale is developed in isolated patches for 

 the most part near the edge of the basin of the Lower Productive 

 Coal Measures of New South Wales. In certain coal seams it is 

 associated with the coal, and occasionally passes rather suddenly 

 into ordinary bituminous coal, Mr. C. S. Wilkinson having observed 

 one instance where the transition occurred in the space of three 

 feet. 



The change from kerosene shale into bituuiinous coal can be 

 traced vertically in the seam as well as horizontally. Mr. W. A. 

 Dixon, F.I.C., F.C.S., in a paper read before Section B. of the 

 Australasian Association*, calls attention to the fact that at Joadja 

 there are three distinct layers in the kerosene shale seam, a lower 

 layer of splint coal, a middle layer of kerosene shale, and an upper 

 layer of good bituminous coal, and remarks (loc, cit.), " It is evident 

 that the differences in the three layers in this seam cannot be 

 ascribed' to any other causes than an originally radical difference 

 in the vegetation forming them." 



In other cases, however, these lenticular patches become stony 

 near the margins, and pass into a very fine-grained black carbon- 

 aceous clay shale, having a splintery conchoidal fracture. These 

 patches vary in extent from a few square feet to perhaps over a 

 square mile, and in thickness from a few inches to five feet. The 

 kerosene shale, though at first sight it appears to be massive, is in 

 reality minutely laminated, as may be observed if the weathered 

 outcrops of the deposit be examined. The laminae occasionally 

 show imprints of Glossopteris and Vertebraria. The former are 



* Proceedings of Australasian Association for the Advancement of Science. 

 First Session, 1888, p. 127. 



