GEOLOGICAL AND MINER ALOGICAL NOTES. 121 



microperthite, albite and orthoclase, good crystals of au- 

 gite, hornblende, aegirine ; numerous crystals of titanite, 

 some biotite, magnetite, a little quartz, some crystals of 

 apatite and zircons. No. 3, section from Goose Cove, is 

 the same as the last except that it does not contain aegirine. 

 Nos. 4, 5, 6, sections from Bay View quarries, contain 

 more augite and asgirine. In one section, No. 5, there is 

 a complete felting of these a3girine crystals which sink to 

 the finest dust as inclusions in the microcline-microper- 

 thite, giving the rock a deep green color. Several thin 

 sections, prepared from specimens collected in East Wen- 

 ham, Essex, Conomo Point and on Cross' island, have the 

 same microscopical structure but are more nearly of the 

 typical augite-syenite. Thin sections from outcrop at Co- 

 nomo point are nearly the same as from the outcrop at 

 Lanesville except that they contain diallage instead of ol- 

 ivine, and sections from the massive outcrop at Powder 

 House hill in the village of Essex contain long acicular 



c o 



crystals of brown acmite instead of the usual segirine found 

 in the various outcrops of the augite syenite. 



Another phase of the augite-syenite rocks is found in 

 the flow structures previously mentioned. When studied 

 from thin sections under the microscope in polarized light 

 they are seen to be different in structure from any variety 

 previously described. The minerals are largely microcline- 

 microperthite, orthoclase and albite. These are by the ad- 

 dition of quartz grains again broken up into a micropegme- 

 tite forming a beautiful mosaic. Other minerals are augite, 

 titanite, hornblende, biotite, hexagonal sections of sodalite, 

 numerous zircons, some colorless garnets and magnetite. 

 In some of the sections there are fine masses of glauco- 

 phane a probable decomposition product of hornblende. 

 One section has mieroliths of segirine in the orthoclase and 

 larger quartz grains. When preparing the preliminary 



