60 T. W. E. DAVID. 
abundant small angular fragments of decomposed dolerite and 
sandstone, together with numerous sand grains. 
About twelve miles north of this mass is a second and much 
larger development of a similar rock at The Valley near Spring- 
wood. This mass has been described by Mr. ©. S. Wilkinson! as 
follows :—“ In the bottom of a gully called the Valley about one 
mile from Springwood, there outcrops a mass of altered con- 
glomerates containing fragments of carbonized wood. I did not 
discover any fossils to enable me to discover the age of the beds ; 
but in their lithological character they resemble the Lower Coal- 
measures of the Hunter River. * * With these conglomerate 
beds occur some trachytic rocks, and in one place there is a spring 
deposit about fifty feet in diameter of brown iron ore.” A cursory 
examination of this mass by myself a few days ago shews that it 
is oval in shape about three-quarters of a mile in diameter from 
east to west, and nearly half a mile from north to south. Towards 
the centre a good section is seen of the eruptive rock which is 
there a very hard volcanic breccia, similar to that already 
described at Euroka Farm. Crystals of augite up to three-quarters 
of an inch in diameter are abundantly distributed throughout the 
mass, and fragments of very slightly altered bituminous coal, from 
a fraction of an inch up to three inches in diameter, are very 
abundant in places. There is evidence of an older and newer 
breccia as fragments of the older breccia may be noticed in 
places enclosed in the newer. The intrusive character of the 
mass is proved by the vertical position of large fragments of sand- 
stone and their alteration near the north-east edge of the intrusion. 
The surrounding Hawkesbury Sandstones are almost horizontal. 
The Valley forms a flat-bottomed depression about five hundred 
feet below the level of the top of the surrounding Hawkesbury 
Sandstone, and five hundred and fifty feet above the level of the 
sea. It is difficult to decide as to the exact part which these 
eruptive masses at the Valley and at Euroka Farm have played 
in the basic eruptions which visited this district in Post-Triassi¢ 
1 Annual Report, Mines Department, 1882, p. 139. 
