199 
xi West of Woodside (stone reserve, Section 
221, Hundred of Onkaparinga). 
Macroscopic character s.—Fine-grained, white 
quartzite, highly felspathie, breaks across the grains, much 
jointed. 
Microscopic characters —Very fine in tor: 
ture, much crushed, and perfectly cemented. All the con- 
stituents in extremely angular grains. No recognisable com- 
posite grains, otherwise the rock is mineralogically very simi- 
lar to the type rock of Mitcham, but felspars of all types are 
rather more abundant. There is a little clastic mica, but 
none that is certainly secondary. А small amount of inter- 
stitial chlorite is present. 
xi. Anna Creek Railway Station. (Loose frag- 
ment on the surface. Quartzite hills occur immediately to 
the east.) 
Macroscopic characters.—Very fine-grained 
grey felspathic quartzite, with vitreous lustre on fracture. 
Microscopic characters. —Rather fine-grained 
mosaic of quartz and felspar. Тһе latter mineral is not sv 
abundant as in the Mitcham rock. All the original grains 
were completely rounded, but secondary outgrowth, affecting 
both quartz and felspar, has converted the rock into a perfect 
mosaic. None of the grains show the slightest evidence of 
strain. The felspars are mostly orthoclase, with only a little 
microcline and albite. The secondary rim, in the case of the 
felspar grains, is more kaolinized than the original materia]. 
A little tourmaline and pyrite is present. . The mineral com- 
position of this rock, obtained over five hundred miles north 
of Adelaide, is strikingly similar to that of the rock from 
Mitcham. 
xii Baroota Creek, Flinders Ranges. Under the 
glacial bed. 
Macroscopic character s.—Medium grained, 
greyish-white quartzite, with white felspathic particles. 
Microscopic character s.—Identical in mine- 
ral composition with the rocks of Miteham and Burnside, but 
different in texture. The rock consists of a number of quartz 
and felspar grains, and a good many composite particles se! 
in a “mortar” of fine-grained, angular material of the same 
character, together witk abundance of dolomite in sharp 
crystals, or allotriomorphie aggregates. It is possible thav 
the fine-grained base of this rock is due to the shattering of 
larger particles through crush. Nearly all the quartz shows 
evidence of strain, Lut felspar crystals are present whose 
shape suggests that they have not been subjected to much 
pressure. 
