160 W. G. WOOLNOUGH. 



Geology of the Macleay River Area. 

 Approaching Kempsey from the New England Tableland 

 via Armidale, the dominant formation met with on the 

 Upper Macleay is an intensely jointed slate. No fossils 

 have been met with in this slate series, so the age is 

 uncertain. The dips are at very high angles; and jointing 

 in several directions, also steeply inclined to the horizontal, 

 splits the slates into long prismatic pieces like large slate 

 pencils. These rocks may be as old as Silurian, to which 

 system they were referred by Clarke. Bands of con- 

 glomerate occur at intervals, (as e.g., near Bellbrook) and 

 may be of value as a clue to the age of the beds, and as 

 persistent horizons for working out their distribution. 



These Silurian (?) rocks are strongly intruded by a mass 

 of biotite granite, extensively developed near the junction 

 of George's Creek and the Macleay. 



At Anderson's Peak near Bellbrook, there occurs a cap- 

 ping of basalt some hundreds of feet in thickness resting 

 upon an isolated peak composed of slates. 



On the east, the Silurian rocks are bounded by a series 

 of contorted and cleaved quartzites and slates which we 

 may refer to as the Kempsey slates. The boundary appears 

 to be near Hickey's Creek, where a heavy conglomerate is 

 met with. In the road sections between Hickey's Creek 

 and Kempsey, the slaty rocks exhibit dips in all directions 

 and there does not seem to be any well defined axis of 

 folding. 



On the coast between Smoky Cape and South West Rocks, 

 what appear to be the equivalents of the Kempsey slates 

 occur in broad undulations but with an approximately 

 horizontal disposition as a whole. They are black in colour 

 and intensely hard, as the result of contact metamorphism. 

 This effect is produced by two masses of intrusive rock. 

 The bold promontory of Smoky Cape consists of a porphyrite 



