65 
Low outcrops of gneiss trending in a north-easterly direc- 
tion lie not far to the north of Mount Caroline. 
Mount Crombie. — Still further south, and about twenty 
miles from the above, another conspicuous outcrop of granitic 
rock, bearing the name of Mount Crombie, is situated. Tht 
northern outskirts only of this exposure were visited. They 
consist of gneiss, whose dark planes of biotite strike roughly 
east and west. The rock exfoliates concentrically at the sur- 
face into large shells, which subsequently break up regularly 
into cubical blocks in well-defined rows, corresponding to a 
latent S3'^stem of planes of weakness brought into prominence 
by weathering. A cliorite dyke intrudes the gneiss in direc- 
tion W., 42" N. 
Mount Kintore. — Mount Kintore rises from beneath the 
desert south of the gap that separates the Mann from the 
Musgrave Ranges. It is built up principally of metamorphic 
beds intruded by diorite dykes. The beds, comprising gneisses 
and quartzite, have been thrown into a series of simple folds, 
which is well recognisable on the northern face of the mount. 
Gross shattering and crumbling of the rock have accompanied 
the folding. The strike of the beds varies slightly, about 
south-east, and it is made prominent by the weathering of 
the rock into ridges conforming in direction with that of anti- 
clinal axes. 
At the western end of the outcrop the gneiss is replaced 
by a development of graphic granite ; and diorite intrusions 
traverse the hill in several localities. 
Echo Hill. — Echo Hill lies south of the eastern extremi- 
ties of the Musgrave Ranges. It is one of many minor out- 
crops of granitic rock occurring in this neighbourhood, and is 
composed of gneiss neatly ''lined" with biotite. Is is cut by 
veins of coarse pegmatite, with large felspathic constituents, 
while local developments of epidote are frequent. The rock 
is jointed in planes striking S. 40° W., and dipping 40° N.W. 
The height of the hill is 2,270 feet above sea level (by aneroid 
determination). 
The Mann Ranges. 
General Bemarks. — The Mann Ranges, discovered and 
named by Gosse in 1873, lie to the west of the Musgrave, and 
are separated from them by a desert tract of sandhills bear- 
ing Triodia and Casuarwa. They extend as a more or less 
compact chain in a westerly direction, with a slight trend to 
the north, across the border of South Australia and the 
Northern Territory, a distance of some eighty miles. Isolated 
hillocks can be traced to beyond the border line of Western 
Australia, culminating to the westward in a more pronounced 
development, known as the Mount Gosse group of hills. The 
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