54 
TORBANITE (KEROSENE SHALE). 
fragment of this mineral (sawn by Mr. Payne from a 
larger portion) also formed a part of the collection from 
Cape Banks. It is brownish-black in colour, has a dull lustre, 
and burns freely when a lighted match is applied to it. It1s 
identical with the mineral torbanite which is mined at Hartley 
tralian coast; one of these was on the beagh at The French- 
man, Eyre Peninsula, and the other at the head of the Great 
Bight.) 
III. SALT a Cause or MECHANICAL DISINTEGRATION OF 
Rocks iN Arip REGIONS. 
When visiting Stuart Creek pastoral station in 1904, by 
the kindness of Mr. W. Oliffe, the manager of the station, 
I was taken over some extensive opal deposits on the run. 
These were situated to the northward of Pidleeomina Water- 
ccur in the upper portions of the cretaceous clays, and are 
distributed over a stri country several square miles 1n 
variety, but some of the specimens are beautifully tinted, of 
the greater part of the disi i f 
3 ntegrated opal consisted o 
_ Innumerable assemblage of usa ahata This intimate 
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