BY H. I. JENSEN. 603 



W.121. Loc: Mount Caraghnan, summit. 



1. Handspecimen of a dark colour. 



2. Texture holocrystalline, fine- and even-grained, with pilo- 

 taxitic fabric approaching panidiomorphic-granular. 



3. Composition : it consists of felspar laths, and aigirine-augite 

 in needles and stunted prisms. 



4. Name : -^girine Trachyte. 



W.132. Loc: Damnation Gully, below and north of Mount 

 Caraghnan. 



1. Handspecimen of a brick-red colour; grain-size uneven; 

 fracture rough; lustre silky. 



2. Texture as in W.127 and W.135. 



3. Composition : the same minerals occur as in W.127 and 

 and W.135, with which rocks it has close affinities. It is porphy- 

 ritic in tabular and lath-shaped felspars and in magnetite. The 

 felspar phenocrysts are albite. The other minerals represented 

 are bluish-green highly pleochroic soda-hornblende (arfvedsonite?), 

 haematite, the felspar of the base and ferric decomposition- 

 products. 



4. The haematite is an original constituent and crystallised 

 immediately after the magnetite. 



5. Name : Porphyritic Magnetite Soda-Trachyte. 



W.125 from Damnation Gully is similar to W.132 except in 

 that most of the phenocrysts are composed of anorthoclase 

 showing Carlsbad twinning. 



W.142. Loc: south slope of Mount Caraghnan. 



1. Handspecimen reddish when weathered, greenish-grey when 

 fresh; lusture silky, fracture rough. 



2. Texture : holocrj^stalline, porphyritic hence uneven-grained, 

 with a fine-grained base composed essentially of felspar laths. 



3. Composition : the felspar phenocrysts appear to be partly 

 anorthoclase, partly albite. The felspar of the ground-mass is 

 sanidine or anorthoclase. Biotite occurs abundantly in frag- 



