The basis of the rock is a brownish palagonite-like network 

 enclosing small fragments of stony material and a large 

 number of replacements by calcite of some minerals or 

 inclusions. Other secondary minerals, such as delessite 

 are found in the cavities. It is possible that this tuff may 

 be connected with volcanic rock to the north, and both with 

 the Tertiary eruptives of western Victoria, but the data 

 at hand are too meagre to allow further hypothesis. 



Economic aspects of the Geology.— In view of the pros- 

 pect of a systematic examination into the mineral resources 

 of the island being made before long, and consequent upon 

 the superficial attention paid by the writer to this branch 

 of the subject this note will necessarily be brief. 



Gold.— The quartzite-slate series of beds which forms the 

 bulk of the island is in many places intersected by quartz 

 reefs. These, for the most part seem to be barren of 

 minerals, but the occurrence of a mineralized reef at one 

 place lends colour to the belief that further prospecting 

 should bring others to light. This is at a place on the Sea 

 Elephant River which was prospected by a company some 

 two years ago, but which was abandoned, we believe, largely 

 because of the heavy preliminary expenditure of capital 

 upon road making, trench-prospecting, etc. Reliable data 

 as to the assays were not obtained. The reef runs through 

 the slates, which here dip gently to the west, and in places 

 is eighteen inches in width. It contains much sulphide 

 ore and small samples are said to have assayed well for 

 gold. 



ScheeJite. — At the mouth of the Grassy River at the 

 junction of a granite mass with the palaeozoic rock a 

 deposit of scheelite was worked for some time. The ven- 

 ture apparently lapsed for want of capital. The mine itself 

 was not visited, but in a number of small reefs nearer to 

 the granite abundant indications of copper in small quan- 



