76 
flats. A iDseudo-brecciated aj^pearance within the rock is 
produced by simultaneous precipitations of compounds of 
iron and chromium and chalcedony. Surface cappings of 
travertine and small deposits of magnesite rest upon the out- 
crop in places, and more frequently upon the diorite dykes in 
proximity to it. The deposit is of no great thickness, and 
can be seen on the west directly overlying diorite. Its origin 
is doubtful, as it can hardly be referred to the "desert sand- 
stone," though in some respects it is not dissimilar to it. The 
formation has been proved to be non-auriferous. 
EvERARD Ranges. 
General Remarks. — The Everard Ranees lie to the south 
of the Tomkinson, and south-west of the Musgrave Ranges. 
They are the most southerly of the series of elevations in 
Central Australia, the other members of which have already 
been described. They were discovered in 1873 by Ernest 
Giles, and subsequently (1891) visited by the Elder Expedi- 
tion. . Mr. V. Streich, the geologist to that exjDedition, points 
out* that the Everard and Birksgate Ranges consist almost 
entirely of eruptive granite, although representatives of a 
schistose series overlying the granite were observed, usually 
as outliers of the main range. Mr. Carruthers also pointed 
out that they "are chiefly composed of red granite." f Only 
the eastern limits of the range were visited by the North- 
West Expedition, although the main granitic chain, with 
Mount Illbillie as a prominent feature, was sighted in the 
distance, and therefore the following notes relate to that por- 
tion of the range only. 
Igneous Rocks. — True granitic intrusions, often with 
large porphyritic felspars, have penetrated granitic gneiss. 
The granite at the borders of the intrusions has assumed a 
gneissic character, the apparent planes of foliation having a 
waved and plicated outline. These planes have, beyond 
doubt, been produced by movement of the rock magma after 
partial crystallisation of the constituent minerals. Veins of 
epidote and epidote granite, in whicii epidote replaces mica, 
are general, while interrupted veins of coarse acid secretions 
are not infrequent. 
The intrusion of the granite has taken place in a direc- 
tion a few degrees south of west, and the weathering of the 
softer portions of the rock has left huge, bare massifs, upon 
* Scient. Res. Elder Expl. Exped., Trans. Roy. Soc, S.A., 
vol. xvi., page 83. 
t Rep. to Surveyor-General (Adelaide Observer, January 16, 
1892). 
