1 
Analysis. 
Silica 
- Tron sesquioxide 
protoxide 
Manganese } protoxide 
Lime 
Magnesia trace 
Potash ; 
647 
i. Water, carbonic acid, &c., not esti- 
‘ mated 1314 
100°000 
Rechits, Gladstone, Port Curtis, Queensland. nd.—From a dyke 
cutting through Devonian rocks. It consists of a grey © 
felspathic base containing embedded sanidin erystals—some e scales 
of red hematite and other minerals in smaller psc 2" Very 
vesicular in parts, also — and close-grained in ot 
pecific gravity = 2-23, 
Analysis. 
Alumina 19-902 
Tron sesquioxide 2-410 
$9 protoxide trace 
Man 8 al protoxide we 
Lim 4 
Magnesia : trace 
BOE see RNs gaat 5° 
4°820 
100° ana 
For moro photographic section, see plate VI, I, fig, 10. 
plate Creek 
Fig. 1 the- section of a red orphyry from Stony t yet 
Ouisteng, collected by the late Prof. A. M. Thomson. "No 
i ea ree oo to tender m thanks to Mr. J M. Smith, 
4 x a the Mla 
of Rydney, £ » tor his great assistance coke angen,” Muir, 
phs ry these and other rock sections, also to J. M. istry 
Mages assistant, and to Dr. Helms, aeperaiaty in * Chem ain 
= asan di of Sydney, ré their very valuable help in the an®v"” 
ens. 
; : : tion of ee time I hope to be able to continue the — 
. ure, this present note bei liminary notice 
* ; ‘te car which it is amy pen . we a et 
