255 



Magmatic name : Alaskose. 



(c) Leucocratic Alkaline Trachyte.- 

 House Mountains. 



-Mount Beei-wah, Glass 



Texture : Holocrystalline, aphanitic, trachytic. 



Constituents : Sanidine, soda-sanidine, barkevicite, arfved- 

 sonite (cossyrite (?) or katophorite (?), segirine, mag- 

 netite, zircon ; and apatite, garnet, and quartz in very 

 minute amount. 



Analysis : 



SA ... 61-58 T,0, ... 0-13 



Al,6, ... 17-52 ZrO. ... 021 



Fe,0; ... 2-56 P„0, ... trace 



Feb" ... 0-96 SOj' ... abs. 



MgO ... 0-22 CI ... 0-08 



CaO ... 0-39 F ... n.d. 



Na,0 ... 6-41 S(FeS„) ... 0-08 



K6 ... 6-23 MnO ... 008 



H,0(100°+) 0-30 NiO ... 003 



H„O(100°-) O-U 



CO, ... OOS 99-97 



Magmatic Name : Phlegrose, near Nordmarkose. 



(d) Melanocratic (Phonolitic) Mgirine Trachyte. — Mount 

 Flinders. 



Texture: Holomicrocrystalline, even grained, pilotaxitic. 



Constituents : Soda-microcline, albite, segirine, magnetite, 

 and a little nepheline. 



Analysis : 



S,0, ... 56-7S H,O(100°+) 1-70 



A1,0, ... 14 47 H,O(100°-) 056 



Fe,0, ... 2-80 TiO, ... 200 



Fe'O ... 6-05 NiO ... 05 



MgO ... 34 MnO ... trace 



CaO ... 2-47 



Na,0 ... 8-67 Total ... 100-40 



K,0 ... 4-51 



Magmatic Name: Umpteikose. 



