m 



New Soiith Wales. 



19 



are especially noteworthy at Bowline^ Alley Point, near Nundle. The 

 apparent thickness is about 10,000 feet, of which tlie portion of the 

 series developed at Tamworth forms a little more than the upper 

 half. It is believed the thickness given previously for this portion 

 should be reduced. 



The Woolomin Series consists of red jaspers with Eadiolaria, clay- 

 stones, tuff, and spilites, all in a very altered state. Its extent is 

 large and stratigraphy greatly disturbed. Age, Lower Devonian. 



The general sequence of geological events is believed to be as 

 follows: — 



Deposition of Woolomin and Tamworth Series took place on 

 a sinking coast, and was interstratified with numerous spilite^ flows 

 and layers of tufaceous material. Increase in igneous activity in 



W.S.W. E.N.L 



Fig. 1. Generalized Section, Northern^ Type, about 30 miles long. 



Fig. 2. Southern Type, about 20 miles long. 



1. Woolomin Series. 



2. Tamworth Series. 



3. Baldwin Agglomerate. 

 i. Barraba Mudstone. 



5. Burindi Mudstone. 



6. Rocky Creek Conglomerate. 



7. Serpentine. 



8. Granite. 



the central region brought about the deposition of the Baldwin 

 agglomerates. In the south this activity was expressed by the 

 intrusion into the Tamworth Series of great sills of dolerite and 

 quartz dolerite often very coarse-grained. These are also known in 

 the northern region, but have not yet been so fully studied. Except 

 for occasional bands of tuff and fine breccia, igneous activity was 

 slight in the Barraba times and temporarily ceased in the Burindi 

 era. Orogenic movement commenced in Middle Carboniferous, and 

 was expressed by the heavy conglomerates and the flows of acid 

 lava. This movement (a thrusting directed from the E.N.E.) tilted 

 the strata vertically and slightly overturned them. A great mass of 

 peridotite was intruded into these upturned strata along a line of 

 fault which runs throughout the length of the Radiolarian Series, and 

 has been traced to fifty miles south of bundle. A sill or dyke of 

 serpentine thus runs intermittently for nearly two hundred miles. 

 Pebbles of this serpentine occur among the Permo-Carboniferous 



