﻿260 ME. C. I. GARDINER AND PROF. S. H. REYNOLDS ON [May I9IO, 



Fig. 2. — Plan of part of a stream half 

 a mile south of Garranagerra. 



gives rise to a little waterfall, and below this is an exposure ©f a 

 nodular felsite of a peculiar character. Then, after a slight gap, comes 



the limestone breccia, above 

 mentioned. This is seen in 

 the stream-bed, and is easily 

 traceable over the fields to 

 the west for a distance of 

 100 yards or more. Then 

 follow gritty tuffs appa- 

 rently striking with the 

 limestone breccia, that is, 

 west-south-westwards ; and 

 next come very line, dark, 

 argillaceous tuffs, which 

 occupy the stream for a 

 distance of a little over 20 

 yards. These dip north- 

 north-westwards at 75° to. 

 80°, their junction with 

 the gritty tuffs showing 

 disturbance. They contain 

 rounded bodies, which com- 

 parison with the better- 

 preserved examples from 

 other parts of the area 

 shows to be almost cer- 

 tainly radiolaria ; and the 

 following graptolites were 

 found in them : — Bidymo- 

 graptus extensus. Hall, D. 

 gibberulus, Nich. (several 

 well-preserved specimens), 

 D. hirundo, Salt., and t>. 

 nitidus, Hall. These indi- 

 cate the zone of Didymo- 

 graptus hirundo. They are 

 succeeded by more gritty 

 tuffs (Shangort Beds), the 

 junction with which is not 

 very clear. 

 As regards its appearance in the field, Band 2 (see fig. 3, p. 261), 

 the coarse tuff or breccia, is perhaps the most remarkable deposit 

 of the district. It consists of a fine ashy quartzose matrix, through- 

 out which are closely scattered blocks of felsite reaching a length of 

 8 inches or more. These usually have weathered more rapidly 

 than the matrix in which they are embedded. At one point near 

 the river, about 200 yards north-north-west of Glensaul School, 

 the rock becomes a conglomerate rather than a breccia. Band 3 is 

 seen immediately west of the footbridge, and consists of calcareous 



dfcf-F 



Wall 







< 



'ti 





JU 









fl 







[The length shown is about 100 yards.] 



a = Main felsite mass of Greenaun. 



b = Nodular felsite. 



c = Limestone breccia. 



d = Gritty tuff. 



e — Fine dark argillaceous tuff, with 



graptolites and radiolaria. 

 F = Fault. 



