240 C. A. SUSSMILCH. 



Series, and aggregate several thousands of feet in thickness. 

 They are for the most part well laminated, consisting of 

 alternating lighter and darker layers, the individual laminae 

 sometimes being very thin ; radiolaria are very abundant in 

 some of the layers. Beds of tuff are interstratified with 

 these rocks, and in many places intrude them. 



(d) The Limestones. — These are not common in this dis- 

 trict. The largest bed known to the wiiter outcrops about 

 four and a half miles N.E. of the town of Gloucester, on the 

 road from that town to Bundook near where it crosses the 

 Tugrabakh Creek. This limestone bed strikes N. 40° E. 

 and stands in a nearly vertical position. It is about 100 

 feet in width, and is being quarried for use as a flux at the 

 Cockle Creek Smelting Works. This limestone is of good 

 quality, as may be seen from the following analysis: 1 



Calcium Carbonate ... ... ... 98*11% 



Magnesium Carbonate ... ... ... 0*49 



Ferric Oxide and Alumina ... ... 0*80 



Gangue 1*09 



No recognisable fossils have yet been obtained from this 

 bed of limestone, but it is interstratified with what appear 

 to be, from their penological character, undoubted Devon- 

 ian sediments. 



(e) The Quartzites. — These have been observed only in 

 the Copeland goldfield, where several beds occur, ranging 

 individually up to 10 feet in thickness. One of these was 

 noticed in the underground workings of the Mountain Maid 

 Mine. They are fine-grained. 



Fossils. — The only recognisable fossils so far found in the 

 Tamworth Series are radiolaria and stems of the lycopod 

 Lepidodendron australe, 



1 Mineral Kesources of New South Wales, No. 25, Department of Mines. 

 The Limestone Deposits of New South Wales, by J. E. Carne. 



