PKSftOSft.] 
apatites of Canada. 
27 
ding arc brought out, which are often parallel to the bedding of the 
country rock. Thus at Bob's Lake mine, in Front enac County, a rich- 
green pyroxenite occurs which exhibits this structure. For 10 feet 
down from the surface this apparent bedding can be distinguished. It 
gradually grows fainter, until it disappears in the massive pyroxenite 
below. A similar phenomenon has been observed at the Emerald mine, 
Buckingham Township, Ottawa County, Quebec, and at several other 
places (Fig. G). It can also be seen in the crystalline rocks on Newport 
Island, opposite 'Tiverton, K. I. There, for a depth of from one to two 
feet, an apparent stratification can be seen, and the rock below gradually 
becomes more massive, until it merges into the apparently homogeneous 
mass of the hill. 
Fig. 6. Section in a pit near tbe Emerald mine (looking west), Buckingham, Ottawa County, Quebec, 
Canada. A, apatite; B, pyroxene; C, feldspar; D, pyrite. Scale, 1 inch = G fert. 
The pyroxene occurs in several different forms. Sometimes it is 
massive, of a light or dark green color, and opaque or translucent ; at 
pther times it is granular and easily crumbled. Occasionally it occurs 
in a distinctly crystalline form, the crystals being in color of different 
shades of a dull green, generally opaque or translucent, but sometimes, 
though rarely, almost transparent. The massive variety is the most 
common, and composes the greater part of the pyroxenites found in the 
phosphate districts. 
The associated feldspar is generally a crystalline orthoclase, vary- 
ng iu color from white to pink and lilac; occasionally, as in Denholm 
in'd Bowman Townships, Ottawa County, Quebec, it occurs as a whit- 
sh-brown, finely crystalline rock. The, trap is of the dark, almost 
)lack, variety. Thin sections under a microscope show it to have a very 
(501) 
