190 W. R. BROWNE. 
of the pegmatites, although no actual case was found of a 
pegmatite vein grading into a quartz vein. 
Quartz veins are very common among the altered rocks, 
often grooved and slickensided, and generally following the 
strike of the country. Some of them are metalliferous: 
mispickel occurs in one to the N.W. of ‘‘Kiaora,’’ and I 
understand that silver was formerfy mined in a quartz reef 
at the mouth of Slack’s Creek. Some of the barren quartz 
reefs which outcrop may be connected with the intrusion 
of the Berridale granite. 
The relations of the pegmatites and the gneisses, as has 
been said, are not at all clear. The Cooma gneiss is the 
most likely intrusion for the pegmatite to be connected 
with, but it may be noted that on the hill behind the R.C. 
Church in Cooma, the pegmatites intrude the amphibolite, 
which in turn appears to intrude the Cooma gneiss. More- 
over the well-defined boundaries of the veins would indicate 
the intrusion of the pegmatite after the complete solidifi- 
cation of the invaded rocks. On the whole, however, it 
seems most reasonable to suppose that the injections 
represent the pneumatolytic phase of the Cooma gneiss. 
As for the minor pegmatites—those narrow stringers which 
seam both gneisses and schists—it is hard to say whether 
they are all to be correlated as phases of the Cooma gneiss 
magma or not. 
The very striking, though not constant, association of 
pegmatite and amphibolite suggests that these two may 
represent complementary differentiates from the magma 
of the Cooma gneiss. This, however, is a matter which 
can only be determined, if at all possible, by laboratory 
investigation. 
(b) ORDOVICIAN.—While it is not intended at the present 
juncture to discuss the relations of the metamorphic series 
with the other formations, it may be remarked here that 
