BY W. N BENSON. 551 



Manganese. — At the inner end of a tunnel on either G.L. 271 

 or 262, Parish Ponsonby near Caloola, there is a vein three feet 

 wide of soft crumbly, but seemingly fairly pure wad; other veins 

 occur in the hill. Considering the low price of manganese, it 

 appears to me very doubtful that these can be worked to any 

 profit.* 



Marble. — Large blocks can be easil}' obtained from the Caloola 

 quarries. It is of excellent quality, has been used for statuary, 

 pavements, steps, &c.t 



Slate. — A quarry was opened up on Portion 42 of the Parish of 

 Oalbraith, and a good deal of stone removed; its poor fissility 

 prevents it from being used for roofing slate. It could, however, 

 be used for flagging, kerbstones, shelvings, &c., though rather 

 soft.; It is very fine-grained, black, lustrous. The analysis of 

 this slate was given on p. 537. 



Asbestos. — As described previously, this occurs in narrow 

 veins, is short in fibre, and brittle. Also there is very little of 

 it. It cannot therefore be of much use commercially. 



Diatomaceous EojVih. — An occurrence has been recorded from 

 near Newbridge,§ but I was unable to get any information about 

 it locally. 



viii. — Summary. 



In the foregoing an endeavour has been made to show in some 

 detail the geological and petrographical features of the Newbridge 

 district. It has been shown that the oldest rock is slate, 

 probababl}'' Ordovician, interbedded with contemporaneous 

 iindesite flows; and that higher in the series the slate is Silurian, 

 as proved by the presence of Pentamerus Knightii in the inter- 



"" Pittman, " Min. Resources of New South Wales," pp. 243-4. 



t Op. cit. p. 434; also L. F. Harper, Ann. Rept. Dept. Mines New South 

 Wales, 1904, p. 147. 



% Pittman, " Min. Resources of New South Wales," p. 446. 

 § Rec. Geol. Surv. N. S.Wales, Vol. v. p. 147. 



