272 N. R. Junner: 



Wade's Look-out, two cuttings for road metal' have exposed good 

 sections of these fragmental rocks. The following section is seen in 

 one of these cuttings : — 



A. — Dense, black, aphanitic asli resembling chert; width about 

 7 feet. 



• B. — Coarser grained tuff or ash containing occasional agglomer- 

 atic pebbles of rhyolite. It is well bedded, and dips steeply to the 

 east; width about 5 feet. 



C. — Partially unconsolidated, finely bedded tuff resembling a 

 mudstone; width about 2^ feet. 



Examined under' a lens, numerous flakes of biotite and a few 

 grains of quartz and altered felspar, and a little pyrite and 

 muscovite are discernible in the rock. The tuff is ripple marked in 

 places, but it is impossible to determine whether these markings are 

 due to water action or wind. No fossils, either marine or fresh 

 water forms, were found in these tuffs, and they appear to bt* 

 Entirely sub-aerial in origin. 



D. — Another band of black, flinty ash. 



These pyroclastic rocks all appear to dip at fairly high angles to 

 the east, but they ai-e well jointed and it is possible, but not prob- 

 able, that jointing and bedding were confused by the author. It 

 is possible tKat these tuffs and ashes were originally deposited on 

 some fairly steep slope, but the more probable explanation of their 

 high dip is that they have been sul>jected to later earth movements. 



Section No. HI, black cherty ash, referred to above as A. — Under 

 the microscope angular pieces of quartz and occasional fragments 

 of beautifully zoned plagioclase can be recognised in a crypto- 

 crystalline matrix. A little biotite is also present, and finely 

 divided iron oxide is plentiful. Bedding is distinctly visible. 

 The bedding planes, however, are not straight, but occur in the form 

 of waves, suggesting rippling. 



Section No. H3, bedded tuff, partially unconsolidated, referred 

 to as D. — Microscopically it consists of numerous angular and 

 oval-shaped fragments of igneous rocks largely dacitic in composi- 

 tion. One or two xenolites of sandstone are present in the section. 

 The bulk of the rock, however, consists of finely-divided rock dust, 

 and fragments of crystals, of quartz, felspar, biotite, chlorite and 

 colourless garnet. The whole of the felspar appears to be plagio- 

 clase, and none of the orthoclase, so characteristic of the tuffs near 

 Malory's falls, is present. Chalcedonic silica is well developed in 

 places. 



