220 THK VICTORIAN NATURALIST. 



their appearance, and the most striking feature about the rock is 

 the uniformity of its coarseness over such a large area. At the 

 landing place in the south-west corner of the Corner Basin, where 

 the rock could be first examined, one was struck by the large 

 felspar crystals, but afterwards similar rock was met everywhere 

 with much larger crystals, and is reported similar right down to 

 the Lighthouse, so that it soon lost its novelty in its commonness. 

 Fine-grained rock is comparatively scarce, and is consequently 

 usually interesting where it occurs. On the south side of Oberon 

 Bay there is a fairly large outcrop of fine-textured aplitic-looking 

 rock, the relations of which to the coarser-grained granite are by 

 no means clear, but it appears to be a later intrusion. A similar 

 feature at the Lighthouse is also recorded by R. A. F. Murray, in 

 his report on South-Western Gippsland, in the following words : — 

 " The Lighthouse at the end of the Promontory is built of a very 

 finegrained grey granite, occurring on the spot in the form of a 

 thick band between that of a coarse description." Along the 

 shore at Oberon Bay this rock on weathering is slightly iron- 

 stained, and shows some remarkably regular rings, which at first 

 sight appeared artificial, but which are really a type of spheroidal 

 weathering. Again, some peculiar holes in the rock appeared 

 quite as if they had been drilled, but further investigation showed 

 that there are occasional large felspar crystal inclusions, the 

 decomposition and disintegration of which leaves the hole in 

 question. 



In the coarser rock quartz-veins occur occasionally, and in 

 some cases good specimens of black tourmaline are obtained in 

 the vein quartz, but this mineral is not restricted to the quartz, 

 but is common in the granite in parts, as at the Bad Saddle and 

 Mt. Norgate. The tourmaline is mostly schorlaceous, but some 

 fair prismatic crystallizations were also procured. In some places 

 associated with the tourmaline occurrence Cassiterite makes its 

 appearance, and one prospector's locality was pointed out to us 

 on the way to Waterloo Bay, but no examples of this mineral 

 were obtained by us. 



The coarse-grained granite has, of course, suffered very much 

 from weathering, and some splendid tors may be seen on any of 

 the hills and mounts, and at every point where the granite 

 projects into the sea enormous rounded masses may be seen, 

 which look rather like tors let down to sea-level than examples of 

 marine erosion. Some magnificent examples of weathering occur 

 on the hills south of Oberon Bay — great masses of rock, closely 

 studded all over with large felspar crystals in relief. The felspar 

 appears to answer in all respects to orthoclase, and every crystal 

 appears to be twinned on the Carlsbad type, sometimes simply 

 two crystals, but occasionally rosettes of six or eight crystals 

 blended together. The crystals are a combination of the oblique 



