328 GRKAT SERPENTINE BELT OF NEW SOUTH WALES, vii., 



Zone (a name indicating a local feature only), distinguished by 

 their greater alteration, fracturing, and silicification, from the 

 normal breccias, tuffs, and cherts of the rest of the Tamworth 

 Series. The actual western margin of the Eastern Series is thus 

 difficult to define, and that laid down on the map (Plate xxxii.) 

 is not a sharply marked feature. There is clear evidence that 

 very much of this Series consists of merely highly altered forms 

 of similar types of rock such as occur in the Tamworth Series; 

 while there are few rocks, if any, so utterly distinct as to demand 

 their inclusion in a definitely older, possibly Lower Devonian 

 formation, (the suggested Woolomin Series, a term we have now 

 abandoned). 



Most notable are the masses of tuff and breccia, which occur 

 in the hills east of the Peel River, between Nemingha Creek and 

 Dungowan, continuing those already noted in the north-eastern 

 portion of JSemingha Parish (6, p. 547). These cross the Peel 

 River in the neighbourhood of Dungowan, and strike through 

 the hills west of the river till they come to the Wallaby Mount- 

 ain and Cope's Creek. Some of these are very similar indeed 

 to the normal tuff-breccias of Middle Devonian age, while others, 

 notably a great mass of almost schistose, highly crushed rock 

 running across the western end of Wallaby Mountain, consist 

 of a coarse tuff with abundant inclusions of limestone drawn 

 out into long lenticles. This may represent the Nemingha 

 limestone, but there are also instances where such a tuff is asso- 

 ciated with the Loomberah limestone. Some of the masses of 

 tuff are very silicified, and one instance of jasperised, ferruginous 

 agglomerate appears as if it might be the equivalent of the red 

 tuff of East Gap Hill, described in Part v. (pp. 564-6). This is 

 to be found on the hills east of the Dungowan Hotel, associated 

 with a little vesicular keratophyre. 



Again, in Portions 52 and 146 in the south-eastern angle of 

 the Parish of Nemingha, three hundred yards east of the serpen- 

 tine, is a large belt of agglomerate, together with porphyritic or 

 granular spilite, inclosing a lenticular mass of limestone a 

 hundred yards long and twenty yards wide, with somewhat the 

 reddish crystalline character of the Nemingha marbles, associated 



