34 ANNITERSABT ADDRESS. 



Mr. Gregory calculated then, that the population of miners 

 and their families would not for three years be less than from 

 5,000 to 8,000, but would increase. 



(2.) The next communication made to the Geological Society, 

 on the same evening, is entitled " Observations on some recent 

 Tin Ore discoveries in New England, New South "Wales ; by 

 Mr. G. H. r. IHrich, P.G.S." 



The author speaks first of the granite plateau of which Ben 

 Lomond is the summit, the height of which he gives as nearly 

 4,000 feet above the sea. It is, however, exactly 5,000 feet, as 

 may be seen in my eighth Northern Eeport to the Government, 

 7th May, 1853, p. 17. [Parliamentary Papers, 26th May, 1853.] 



He says the predominant rocks are granite and basalt, in 

 closing subordinate ranges of slate and sandstone ; the basalt 

 having broken through and overflowed the summits, greenstone 

 occurring in the slate. He describes the country as park-like, 

 with the climate of central Europe. He says of Elsmore, twelve 

 miles east of Inverell, that it iu eludes a granite range two miles 

 long, and extending under basalt, micaceous in character, rendered 

 porphyi'itic by crystals of white orthoclase (sometimes several 

 inches long), with occasionally bluish grey oligoclase ; quartz 

 veins traverse the rock up to a foot in thickness, and druses, 

 seams, and crystals of cassiterite stud them. Portions of the 

 veins are micaceous, representing the " greisen " of the Saxon 

 and Bohemian tin ore districts, difteriug only from the rock at 

 Beechworth, in Victoria, in that the granite there is fine and 

 euiitic, and rarely porphyritic. 



He considers the veins of softer granite, which are highly 

 micaceous, ef more importance, the quartz and felspar being 

 insignificant compared with 75 per cent, of mica. 



In these micaceous dykes Cassiterite is distributed in crystals 

 from the size of a pin's head to above that of a pea, and in 

 " nests and branches yielding lumps of mostly pure ore to above 

 50 lbs in weight ; part of the mass of one of these dykes forming 

 a breccia of mica and imperfectly crystallized tin ore, cemented 



