57 
Geological Report on the Country traversed by 
THE South Australian Government North-West 
PROSPECTING Expedition. 1903. 
By Herbert Basedow, Prospector to the Expedition. 
[Read October 4, 1904.] 
Plates XIII. to XX. 
Contents. 
Pre-Camhrian: 
The Ranges of North- W<\st-ern South Australia... 57 
Musgrave Ranges and their Outliers ... ... 59 
Mvann Ranges and their Outliers ... ... 65 
Tomkinson Ranges ••■ ... ••• -.- 73 
Everard Ranges ... ... ... ... ... 76 
Ayers Ranges, Northern Territory ... ... ... 77 
The Indulkana Outcrop ... ... ... ... 79 
Cambrian : — 
The Head of La ke Torrens 81 
Ordovician : — 
The Mount Chandler Outcrop 82 
Mount Conner ... ... ... ... ... ... 83 
The Mount Kingston Outcrop ... ... ... 84 
Mount Olga and Ayers Rock ... ... ... 85 
Supra-Cretaceous : — 
The Desert Sandstone ... ... ... ... 86 
Becent Surface Deposits, Sa.iidhills, etc. ... ... 89 
Aijpendia' : — 
Petrological Notes on Rocks collected during the 
Expedition ... ... ... ... ... 91 
The Ranges of North- Western South Australia. 
Although maps represent these ranges as separate en- 
tities, they must, on geological and lithological grounds, be 
regarded as belonging to one and the same grand system, the 
intervening tracts of country which now separate the indi- 
vidual ranges being, for the most part, superficial deposits 
of comparatively recent sands and sandhills, or supra-creta- 
ceous deposits, known as the 'desert sandstone." 
Rising abruptly f from the surrounding sandy country, 
* This paper, which has been slightly abridged, was the suc- 
cessful Tate Meniorial Medal Thesis, 1904. 
t Compare J. Forrest, Explorations in Australia, III., page 
248: — ''The Avhole country is level, the ranges rising abruptly out 
of the plains, . . " Also the general st^itement by James 
Geikie, in Earth Sculpture, page 202: ''Pisiiig boldly above 
the general level, they exhibit no trace of talus or debris. . . ." 
