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PLUTONIC ROCKS.—CASE III. 17 
61. GREENSTONE. List No. Rsr 6. 
Mount Purrumbeet, Lake Cooper. 
Greenish-black mottled rock, with 
specks of iron pyrites. 
62. GREENSTONE. List No. Rsr 6. 
Same locality as last, 
The same base as last, with a few 
scattered crystals of triclinic felspar. 
63. GREENSTONE. 
Mount Camel Range, Colbinabbin. 
A concretionary nodule, From a well 
80 feet deep in greenstone ; fresh, good 
water, 
64. GREENSTONE (Diabase). 
Barrabool Hills, west of Geelong. 
ł sheet 24 S.E. 
A hard, greenish-black, crystalline 
rock, probably composed of green 
labradorite and black augite, though 
the silica in the soluble portion is rather 
too low. The analysis by Mr. J. Cosmo 
Newbery gave as follows :—* 
Soluble Insoluble 
portion, | portion. 
Silica .. ++ 46°34 . 53°94 
Tron, sesqui-oxide 1-30 fe } 11-78 
, ne protoxide 
Alumina .. e+ 29°05 ay 2°80 
Lime .. ++ 1456 14°39 
Magnesia .. ©. 3-44 . 16°13 
Soda . ? 
Potassa .. 4°51 
Loss by ignition <. 175 
100°95 os 99°04 


* 40°06 per cent. is soluble in hydrochloric acid. 
(See Table of Analyses, page 94.) 
65. GREENSTONE (Diabase). 
Same locality as last, 
Identical with No. 64, but more highly 
crystallized. 
*66. DIORITE. Map No. R 98. 
Near S.E. corner of section 15, 
parish of Metcalfe. 4 sheet 
13 S.E. 
A very hardrock. It occurs travers- 
ing Silurian strata, and is composed of 
triclinic felspar and hornblende, 
67. DIORITE. 
Tarilta, or K. angaroo, near Guild- 
Jord. 4 sheet 15 N.E. 
See Note. 
(See Table of Analyses, page 94.) 
68. DECOMPOSED DIORITE. 
Same locality as last. 
This specimen was taken from the 
junction with the graptolite slates of the 
neighborhood. 
See Note. 
69. DECOMPOSED DIORITE. 
Same locality as 67. 
See specimen 68. 
See Note. 
70. Ermosite (Epidote Rock), 
Same locality as 67. 
Composed of light-green epidote, 
quartz and occasionally crystals of 
hornblende. (See Table of Analyses, 
page 94 and No. 7.) 
See Note. 
Note.—The diorite specimen 67, composed of pinkish felspar and 
black hornblende, was taken from a peculiar intrusive mass of rock, 
several acres in extent, that in most places, where exposed, consists of 
diorite, but assumes at others granitic, syenitic, porphyritic and brecciated 
characters. Thus, at its junction with the black graptolite slates of the 
neighborhood, where several small faults have been traced (see sketch on 
+sheet 15 N.E.), the rock bears the character of porphyry, more or less de- 
composed; whilst at another place, scarcely four chains off, the accession 
of black mica and some quartz renders the rather decomposed rock undis- 
tinguishable from decomposing granite ; and from one of the small shafts, 
sunk for the purpose of examination, specimen’ of “ epidosite ” (vide 
No. 70) were also obtained. In small cavities of the porphyritic variety, 
crystals of “ albite,” associated with abnormally formed quartz crystals, 
occur, and it was therefore probable that the felspar, entering into the 
, composition of the rock, might also be “ albite,” though the absence of 
the characteristic twinstriation on its cleavage planes gives it all the 
appearance of orthoclase. The result of Mr. J. C. Newbery’s analysis 
Those marked with an * occur ag dykes (Elvans), 
Cc 
