Some Kyaxite-eeakixo Kooks from the Easteex Goldfields, 
Western Austratra. 
19 
Chemical analyses of Talbot’s rock and of one of these (1/2695), given 
below, clearly indicate* their common composition, however, and strongly 
sug‘g‘(‘st their common origin. 
(^fCINN’S, ArUKCHTSON GOLDFIELD. 
F ieJd occurrence. 
From a little over half a mile to the south-west of (jluinn’s townsite in 
the Murchison Goldfield, comes another set of metamorphic schists, com- 
parable with those described above. These rocks were iirst described in 1904 
by C. G. Gibson (18) who believ(*d them to be ga-anite schists. In 1921 they 
were further described and figured by F. K. Feldtmann (19) and a brief 
account was gi\-(m of tluii’ field occuri'eiice. Petrogra [)hic descriptions of a 
number of these rocks were provided by K. A. Far(|uharson (19, pl6) wfu» 
considei’ed sevei'al ol them (1/791-2) (1/794) (53.42-.'l) to lie metanioT’|)hic 
chloritic ipunlz schists containing a granular mineral which he doulitfully 
I'cferred to andalusite. Eddtmann concluded that they were contact meta- 
inori>hosed sediments. Analyses of two of the rocks (1 791 and l '7f)2) 
Avhidi are (juoted below, were also published. 
Petrograjdiff. 
Hand specimens of one of these metamorphics (1/791) are pale greamish 
grey coloured, rat!i<‘r uneven, medium to hue grained, granulated with an 
unusual streaky ai)pearanc(‘, consisting mainly of ]nnk and I'olouiless quartz, 
.and abundatit pale green (ddorite scales. 
This rock has a granulated ])or])hyroelastic t(‘xture, witli scattered “eyes” 
of slightly broken, cleai* (piartz in a tine grajiulated matrix of rounded (piartz 
■gTains and chlorite* shreds. The gratiular mineral referred to andalusite })y 
Faniuharson occurs in several roughly rectangular patches, enclosing abund- 
ant grains of <|uarlz and chlorite and some rutile iLcedles. The determinable 
optical chai’acters of this mineral two those of andalusite present iti a \'(‘ry 
early stage of sk(‘leton growtli. 
In addition to the andalusite, tin* specinum also contains kyanite in a 
tew small ragged elongatetl prisms, usually enclosed by and apparently de- 
veloping at the expense of chlorite, but also occasionally associated with the 
andalusite. These crystals have modej'ately high relief, moderate birefring- 
ence, positive elongation, maximum extinction angle on (100) of about 30° 
A^Oj negative optical character and large axial angle., and undonbtedly 
re])resent an incipitait growth of kyanite. 
Other minerals include scales of muscovite associated with abundant 
altered chlorite, a few cloiuly grains of knolinisod felsjnxr, rutile in jiale 
yellow prisms, a few clusters of dark yellow irregulai* shaped granules with 
extremely high relief (probably brookite), zircon, apatite and a little granular 
carbonate. 
A second rock (1/792) from the same area has a similar tf'xture in hand 
specimens but is of a mottled pink colour. Small clear white crystals of 
andalusite ean be seen scattei’ed through a fine granular matrix of pink 
('luaidz and pale green to colourless mica flakes. 
The thin slice reveals a ty])ica.l porphyro])lastic granular texture of 
andalusite in (piite well crystallised produefs crowded with fluid inclusions, 
grains of (piartz and a fow i-utih* lu'cdles, and usually surrounded by and 
