534 THE GEOLOGY OF NEWBRIDGE, NEAR BATHUKST, N.S.W., 



probably Silurian, the only fossil recognisable being a Pentamerus 

 found in the interbedded limestones; but it is quite possible 

 that much of the slate is Ordivician,* though so far I have seen 

 no sign of graptolites. As to whether they are highly contorted 

 or not, I have little evidence. Slaty cleavage is developed to 

 such an extent that all sign of the original stratification is lost. 

 The strike of the cleavage is very variable, ranging from N.N.W. 

 to N.N.E., and the dip east or west at 50° to 90°. From 

 examination of the Caloola limestones, I believe the true strati- 

 fication strike to be N.N.E. and S.S.W. Should the andesites 

 be interbedded with the slates and not intrusive into them, we 

 should be able to use their junction with the slates to give us 

 the true dip and strike; and by this test it would seem that, at 

 the junction, the dip was to the east at 70°, but that the strata 

 were rather contorted; though as previously pointed out the dis- 

 tinction between decomposed andesites and decomposed slate is 

 rarely clear at their junction. 



In this region the slates contain fissure-veins filled with iron 

 ore (detailed later), and in one place indications of a copper lode; 

 and are netted with man}?- quartz veins. One of these veins is so 

 notable as to merit description. It is first seen capping a small 

 rise by the road-side in Portion 10, Parish of Galbraith, though 

 it does not occur in the road-cutting below, where there is a wide 

 band of soft pipeclay which represents the slate out of which the 

 silica was bleached to make this great vein. The leaching out of 

 the silica was also accompanied by a removal of the iron, for the 

 pipeclay is nearly white, and the iron is segregated in a vein of 

 siliceous haematite near by. The quartz capping the hill is 

 almost pure. As we pass to the north-west, we cross a small 

 valley where there is no sign of the reef. It occurs again on the 

 top of the next hill (Portion 35) among the andesites, and forms 

 a great scarp or wall running down the hillside. It does not 

 occur in Pteedy Creek, but forms a large patch (not marked on the 

 map) on the flank of Smith's Hill opposite. Hence the vein forms 

 what may be called a horizontal pipe vein. 



* J. B. Jaquet, " Iron Ore Deposits of New South Wales," p. 20. 



