BY THE REV. J. MILNE CURRAN. 201 



A junction of granites and Silurian rock can be well seen near 

 the bridge over the Winburndale Creek, on the Bathurst-Peel 

 Road, a few hundred yards up stream. Two rocks are noticeable, 

 one of flesh-coloured granite, which is very marked in its contrast 

 with the other, a massive, compact, bluish rock — a hornfels or 

 altere 1 slate. The granite is mainly binary with striugs and nests 

 of translucent quartz. There are occasional flakes of black mica, 

 and layers of white mica are sometimes developed along the joints. 

 The flesh-coloured porphyritic granite sends veins of varying 

 thickness into the hornfels. One vein, not above an inch in 

 thickness, is shot in a right line into the altered slate for fully 20 

 yards ; see PI. xv. tig. 5. 



In the same locality I noticed a granitic vein springing from the 

 main mass of granite and entering the hornfels as a dyke about a 

 foot thick. A short distance away it is narrowed down to five 

 inches, at the same time bending round to form a right angle with 

 the first direction and then continuing in a right line in its new 

 course. Smaller veins connect the two arms at the angle. A 

 diagram of this interesting intrusion will be found on PI. xv. fig. 6. 



A little further along the same road, in the direction of Bathurst, 

 a tributary of the Winburndale is crossed. It is dry at most 

 seasons of the year. By following up this creek, a variety of 

 rocks will be met with, indicating that the junction of the slate 

 and granite is not far off. Near the culvert, in fact under it, 

 splendid samples of " spotted slate " can be found with a general 

 strike to the north-west. 



I will narrate, in the order they are met with, some of the 

 varieties of rocks that may be studied here, following the creek up 

 from the road. 



1. Some three hundred yards from the culvert there is a vein of 

 felspathic rock, containing blebs of translucent quartz, silvery 

 mica, and quartz veins. This is some three feet in thickness, and 

 contains inclusions of a schistose hornfels. 



2. Slate, dipping north-east at a high angle. 



