56 Rocks of Noyang. 



few large flakes of niuscovite mica. The only microliths are 

 a few very small, stout, colourless prisms, and a few yellow 

 granules, and some carbonaceous material. In this " paste" 

 there are very numerous angular fragments of quartz, and 

 angular and rounded fragments of felspar. These fragments 

 are of such size, as compared to the remainder of the rock, 

 as to give it a pseudo-porphyritic aspect. 



The quartz is such as is found in the crystalline-granular 

 granite rocks, and contains numerous and very minute fluid 

 cavities. Some of the fragments of felspar have all the 

 appearance of orthoclase, others are plagioclase, and in one 

 fragment of the latter I observed the angle formed by the 

 plane of vibration in either side of the twin composition 

 face to be 40°. 



Besides the fragments of quartz and felspar which form 

 the greater part of the rock, there are also several rounded 

 fragments which are yellow in colour, contain iron ores 

 (magnetite?), and are isotropic. They have, in fact, exactly 

 the appearance of a volcanic glass, which I believe them to 

 be. There are also some fragments of green tourmaline, and 

 a good deal of brown iron ore generally distributed through 

 the slice. This rock has therefore been formed from the 

 detritus of igneous rocks, which were probably developed 

 both in crystalline and vitreous forms. The examination 

 of a rock such as this suggests that an investigation of the 

 most coarse-grained of the Silurian beds of Victoria might, 

 perhaps, give some insight into the nature of the still older 

 formations of which at present, so far as I am aware, nothing 

 is known. At any rate, it seems that in Gippsland those 

 formations on which the Silurian sediments were laid down, 

 and from whose waste they were most likely formed, have 

 completely disappeared during the metamorphic and plutonic 

 processes to which the palasozoic rocks have been subject. 



I prepared several other slices, which did not afford me 

 any special points of interest, being either the same as, or 

 intermediate to, the above. 



Northern Side of Shady Creek Range. — The first sample 

 which I examined has, in the hand specimen, a finely-foliated 

 structure, and a silky lustre on the bedding planes or folia- 

 tions, and also a few slightly marked spots like incipient 

 " nodules." Under the microscope I found this rock to be 

 composed as follows : — 



(a) Foliations of almost colourless thin overlapping plates, 

 which react as a uniaxial mineral. 



