Rocks from Ni Britain and New Ireland. ; See: : 
x By A. Lavenstpcn, F.R.S., Professor of haroogy 4 and Mineeulegs? ue 
« n tne University of Sydn 
pomg'? (Preliminary Notice.) - MS 
See ee ee ee 
[*Read before the Royal Society of N.S.W., 8 December, 1880.} goo 
THE specimens forming the subject of this notice were col rahe 
in the year 1875, by the Revd. George Brown, Wesleyan ie Tha 
o whom my thanks are due for the sei rag Se Of 
examine these and other specimens which he has brought from <i ae 
the Islands from time to time. a 
Sipatovinnins FROM New IRELAND. : * ae 
srry —TIn the collection are several well rounded palin : 
porphyry. In all of them the felspar crystals are small but — 
‘ily well defined, embedded in afelspathic base or paste. In most _ 
the base is some shade of green, the colour varying from bs 
light toa dark green ; in one case the base is reddish brown or 
chocolate colour, and in this instance some of the felspar crystals ne 
are somewhat larger—one being about }” across. thee 
Diorite—Com of a white felspar and quartz, with dark 
green hornblende, without mica. o 
Caleite.—In the form of veins, some nearly an inch thick, bates 
Tuning through a dark brown rock, which is evidently of igneous rete 
origin, and possesses a slightly porphyritic structure in part, with 
obscure white atone ay stals. Almost colourless, and readily 
ng cleavage rhom 
(ER arious forms—one somewhat crystalline, with ce 
reddish brown Heats might be described as a marble ; does not. 
Appear to have been derived from recent coral rock. a 
A pebble of dark grey compact limestone, from the Mate Kaa ee 
: River, bnt weathered almost to a white colour for about 3,” from 
2 cies added; but Oy merce inty oh eee 
