297 



minerals being chiefly uralite, chlorite, epidote, calcite, 

 and sericite. Such alteration is similar to that which 

 takes place under conditions of moderate to shallow depths 

 and moderate temperatures, and probably took place 

 during the folding and shearing that the volcanics suffered 

 in orogenic periods. However, near the contacts with 

 the intrusive granitic rocks the volcanics have been 

 greatly contact metamorphosed and some of them have 

 even been recrystallized or replaced, forming various 

 metamorphic types such as silicified and feldspathized 

 varieties, amphibolites, and even garnet-diopside-epidote 

 rocks. Analyses of the two last types are given below. 

 The volcanics are also seamed with veins of quartz and of 

 quartz and epidote, and in places are impregnated with 

 metallic sulphides, chiefly pyrite. 



Si0 2 



A1 2 3 



Fe 2 3 



Fe O 



MgO 



CaO 



Na,0 



K 2 



H 2 0+ 



Ti0 2 



P 2 E 



MnO 



Specific gravity 



I. 



2. 



51-60 



42-86 



15-00 



7-19 



1-85 



14-24 



8-48 



4-28 



7-15 



2-96 



7-63 



26-30 



3-09 



0-27 



0-70 



o-33 



i-95 



1 -oo 



2-00 



0-30 



0-18 



0-21 



0-24 



0-50 



99-87 



100-44 



2-95 



3-44 



1. Amphibolite, Iron Mask Mineral claim, south of 

 Mill hill, Esquimalt district. M. F. Connor, analyst. 



2. Garnet-diopside-epidote rock, Iron Mask Mineral 

 claim, Mill hill, Esquimalt district. M. F. Connor, analyst. 



The Sutton formation is composed of crystalline lime- 

 stone or marble, occurring as lentils intercalated in the 

 Vancouver volcanics throughout their entire thickness. 

 The lentils are small, only one of them, namely that extend- 

 ing from Esquimalt harbour west to Colwood plain, being 

 over a mile long. The crystalline limestones are gray to 

 grayish blue to white, compact to medium grained, and 



