MAKSHAjiL. — Geological Notes on Soutli-ivest Otago. 501 



often intergrown with quartz, in which case the hornblende is 

 optically continuous in large plates, and the thin arms of inter- 

 grown quartz are also continuous, so together they form a 

 graphic structure. The boundaries of the hornblendes are highly 

 irregular. Inclusions of brown rutile rather frequent. Quartz 

 frequent, but in rounded and irregular grains, filling up spaces 

 between the other minerals. Epidote almost colourless with no 

 evident pleochroism, often 1 '5 mm. by 0-5 mm. in size ; appar- 

 ently an older constituent than the hornblende. Garnet pale- 

 pink, in large grains, highly irregular and discontinuous, with 

 the interspaces filled with quartz, hornblende, or rutile. Very 

 small amount of triclinic feldspar (Plate XXIII, fig. 3). In 

 another section there is a quantity of colourless rutile sometimes 

 surrounding the brown grains. 



(G 27) : A rock showing very distinct banded structure. 

 The bands are coloured light-brown and white. In section the 

 brown bands are seen to be composed of minute plates of biotite 

 with some granular quartz. The white bands are composed 

 entirely of quartz. The individual grains are small and angular. 

 Occasionally larger rounded grains of quartz and round garnets 

 colourless in section. The structure is completely cataclastic. 



Anita Bay (G 31) : A black rock evidently composed of 

 hornblende. Section entirely hornblende, ^\^th intensely strong 

 pleochroism — c, bluish -green ; 6, grass-green ; a, very pale- 

 yellow. 



Island Beach Harbour, Breaksea Sound (G 15) : Hand- 

 specimen shows large granular groups of hornblende crystals 

 imbedded in a white feldspathic mass. Section : Very little 

 quartz ; orthoclase and oligoclase plentiful. Larger irregular 

 crystals of brown hornblende, sUghtly pleochroic, in many places 

 changed into green fibrous hornblende. Some finely granular 

 epidote interspersed with the fibrous hornblende. A good deal 

 of granular brown rutile. 



Beach Harbour (G 8) : Very similar in hand-specimens and 

 sections to the garnetiferous rock from Duck Cove. OUgoclase 

 is much more frequent ; quartz less frequent ; and there is a 

 little greenish-brown hornblende. 



Duck Cove (G 24) : Hand-sjjecimen shows abundant garnets 

 associated with a black ferro-magnesian mineral. These groups 

 are imbedded in a white base. In section the garnet groups 

 are granula,r, and the ferro-magnesian mineral is a pale-green 

 faintly pleochroic pyroxene. The white minerals are quartz 

 \vith highly irregular margins, and oligoclase. Much brown 

 rutile associated with the garnet-pyroxene groups (Plate XXIII 

 fig. 4). 



Duck Cove (G 19) : A fine-grained pale-green rock. Sec- 



