104 



PROCEEDINGS OF SECTION C. 



would suggest their correlation with the carboniferous granites of 

 New England,^ a suggestion supported by their low erosion relief. 

 On the other hand, the nearest granites are those of Moonbi, which 

 are stated to be mesozoic. The Duncan Creek rocks are not, how- 

 ever, sphene-bearing to any marked degree, as are those of Moonbi, 

 as far as has been ascertained. A section along a line further south 

 than A.B.C.D. would show a much smaller angle of dip for part 

 oi the Nu'ndle series. 



Part II. — Abstract. 



Suess has shown that ultrabasic rocks in general form sills in 

 dislocated mountains, and have been intruded into bedding or fault 

 planes during the period of crust movement. Attention is here 

 drawn to the fact that ultrabasic rocks in Eastern Australia and 

 Tasmania occur in sill-like masses in folded rocks, and have their 

 maximum extension in a direction lying between north and north- 

 west. (See fig. 1.) As far as is at present known the only exception 



Ultrabasic Rocks. 



Fig. 1. 

 Diagram showing Distribution of Ultrabasic Rocks in Eastern 



Australia. 



