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Mount Painter rocks, the relics of sedimentary formations were noted, the more 

 obvious being highly altered quartzite and boulder conglomerate. 



On the track down Sphene Creek the more obvious gneisses are crushed 

 igneous types, amongst which augen-gneiss figures. Igneous rocks which have 

 suffered only minor metamorphic changes are also present, for instance, granite, 

 sometimes porphyritic, is a feature, and in some phases its appearance recalls 

 the Boolcoomata granite of the Olary district. 



Two specimens of the more acid igneous rocks from this portion of the 

 section from known localities are available for description. 



The first is a sircon-biotite-syenite which forms a considerable outcrop in 

 the creek about two miles below Mount Gee. In the hand specimen it 

 appears as a light-grey rock in which large white felspars, frequently three- 

 quarters of an inch in length, are the most conspicuous feature. A gneissic 

 parallelism of these felspars is discernible. Between the porphyritic felspars is 

 a fine-grained matrix of quartz, felspar, and reddish-brown mica. 



The microscope section shows that the rock has undergone some crushing, 

 the edges of the porphyritic individuals have been granulated, and the fine 

 base material, which is of an allotriomorphic granular character, exhibits fre- 

 quent inclusions of one mineral within the other to such a degree as to suggest 

 recrystallization in part. The porphyritic felspars have the general characters 

 of anorthoclase- Elsewhere the felspars are represented by orthoclase micro- 

 cline, acid plagioclase, and perthite. Quartz is plentiful but only in small 

 individuals ; it would appear to be insufficient in quantity to characterise the rock 

 as a granite. Biotite is plentiful in very small fragments, strongly pleochroic 

 from colourless to reddish-brown. Small grains and prisms of zircon are com- 

 paratively numerous. Grains and rods of apatite are rare. This rock seems 

 best described as a zircon-biotite-syenite. 



The second specimen, a somewhat altered qiiartz-felspar-porphyry, comes 

 from an outcrop forming a bar in the creek bed about a mile below that just 

 described. The hand specimen is a pink-coloured, dense rock in which are 

 discernible small quartzes with a bluish opalescence and the outlines of numerous 

 porphyritic felspars set in a felsitic base. 



In section under the microscope the quartzes are seen to be badly strained. 

 The felspars, which were apparently orthoclase, are largely changed to crystalline 

 aggregates ; some are quite indistinct relics. The base is constituted of fine 

 felsitic granules. Grains of magnetite and some very tiny fragments and broken 

 wedges of colourless sphene are also present as primary minerals. There are 

 present also some very minute granules of honey-yellow to bottle-green colour 

 which look like pistasite, but as they appear to be primary may be monazite. 

 The ragged edges of the primary minerals indicate at least some degree of 

 mashing. This rock was evidently originally a quartz-felspar-porphyry, but has 

 undergone considerable metamorphic recrystallizations, without any marked 

 dynamic alteration. 



A specimen of a light-coloured, fresh-looking granite from amongst the 

 collection made in the Mount Painter belt is worthy of reference, though its exact 

 locality is wanting. 



In the hand specimen it appears as an even-grained granular rock in which 

 flesh-coloured felspars stand out amongst white felspars, quartz, and muscovite. 

 Microscopically the felspar is noted to be microcline, orthoclase, and an acid 

 plagioclase. The latter, which is very near to albite, is rather abundant. Quartz 

 is plentiful and muscovite plates numerous. The rock is very fresh, and appears 

 to have been strained, but has not suffered crushing. The orthoclase felspars 

 and the quartzes show shadowy extinction and the mica plates are bent. By 

 reason of the abundance of plagioclase this rock tends towards the adamellites, 



