looks like a hardened cream coloured claystone, though 

 without cleavage or jointing. In a specimen of such a rock 

 was found a small fragment of an altered peridotite. 



From Mr. Arthur Coombe I have received a specimen of 

 another type of basalt also found as inclusions in the breccia. 

 I have, myself, also noted it in breccia by the road at the 

 south entrance to the quarry. At first sight it appears as 

 an oolitic limestone, and is scratched readily. The "oolites" 

 are green, and about two or three millimetres in diameter. 

 On sectioning, the rock proves to be a holocrystalline, 

 pilotaxitic basalt, containing much calcite. The augite 

 was finely granular and is almost completely decomposed. 

 Decomposing titaniferous magnetite is very abundant. 

 Small flakes of brown mica are common. The "oolites" 

 are wrapped round by felspar laths and are filled either 

 by very faintly coloured chlorite in beautiful radiating 

 aggregates, or lined with chlorite hemi-spherulites, the 

 central portion being composed of a single or twinned 

 crystal of calcite, either unbroken, or dotted through by 

 small spherulites of chlorite. Dr. Woolnough suggests 

 these "oolites" were steam filled vesicles, which expand- 

 ing, when the pressure was released by eruption, forced 

 aside the already formed felspar laths, thus causing them 

 to appear as if wrapping round the chlorite and calcite. 

 The idea that these areas are pseudomorphous after olivine 

 is negatived by their approximately spherical shape. This 

 same shape also shows that the enlargement of the vesicles 

 continued after active flow had ceased, otherwise they 

 would have been more amygdaloid. 

 The Basalt. 



The basalt that fills the plug and runs in dykes out 

 from it is that which has been chiefly used for road 

 metal. It has been described briefly by Mr. G. W. Card. 1 



1 Rec. Geol. Surv. of N.S. Wales, 1903, Vol. vu, Pt. iii, p. 229. 



