126 Charles Fenner 



III. — Previous mention in literature. 



Since the commencement of investigations into this occurrence, 

 two prior references to it have been found ; the exact places referred 

 to are not known, but there are several places where the abundance 

 of quartz is striking. 



(a) Major Mitchell, who ascended and named Mt. Greenock in the 

 year 1836, records in the " Journal " of his explorations, that on 

 September 25th, when nearing the mount, he " passed over a 

 ridge of trapean conglomerate, with embedded quartz pebbles/' 

 Again, on September 26th, he records more hills of the " trapean 

 ■conglomerate." " The rock," he says, " consists of a base of com- 

 mon felspar, with embedded grains of quartz, giving to some parts 

 the character of a conglomerate, and there are also embedded 

 crystals of common felspar." 



(b) Mr. E. J. Dunn, who knew this district very well, says, in his 

 book on " Pebbles," page 47 : " At Mount Greenock (Vic.) the 

 auriferous tertiary lead was broken through by a volcanic outburst, 

 and the crater of Mount Greenock formed over its former course 

 .. . . The pebbles became entangled in the flow- of basalt." Again, 

 on page 63 : " Where volcanoes break through conglomerates, pebbles 

 may become entangled with the lava flows, and by this means be 

 transported to some fresh site; an instance of this occurs at Mt. 

 Greenock." 



While this simple explanation may be the true one, there is no 

 definite proof that such is the case. Indeed, there are some' reasons 

 for doubting that this would fully account for the presence and mode 

 •of occurrence of the quartz. 



IV.— Distribution, etc., of the Quartz. 



In the Mt. Greenock flow, as far as it has been examined, over an 

 tirea of about two square miles, the distribution of the quartz 

 through the rock is by no means uniform. While there are places, 

 such as Walker's Cliffs (A in map), the schoolyard (B in map), and 

 others, where the quartz is so abundant that the basalt resembles a 

 conglomerate, yet in other places it is sometimes only possible to 

 find one small crystal to an ordinary hand specimen, and in other 

 places it is still more rare. 



The size of the quartz fragments is very variable, and in shape 

 much irregularity is also shown. Nothing that could be definitely 

 called rounded or even sub-angular occurs. 



