224 DESCRIPTIVE CATALOGUE 
30. Hornblendic rock— coarsely crystalline; the crystals black and honey-_ 
coloured ; some quartz; ferruginous. 
31. Siliceo-argillaceous slate—would make good roofing and writing slates. 
32. Argillaceous slates—very thinly laminated; decomposes easily. 
33. Greenstone—very fine-grained. 
34. Porphyritic greenstone. 
35. Syenite—passing into greenstone, like No. 11, contains flesh-coloured felspar. 
36. Hornblende rock. 
37. Decomposing hornblende rock. 
38. Clay-slate, unaltered. 
39. Metamorphosed clay-slate. 
40. Hornblende rock, in contact with No. 39 ; contains Labrador hornblende. 
41. Red siliceous porphyry—contains occasional lumps and crystals of quartz ; 
the felspar crystals tabular, red, numerous. Grains of oxide of manganese with an 
undetermined mineral, are disseminated through the rock in considerable quantity, 
and also line the joints between many of the felspar crystals, and the embedding 
paste. The paste is often fine granular. 
42. Slaty greenstone—minutely crystalline. 
43. Hornblendic rock—resembles the slaty greenstones of Big Fork River. 
44. Argillaceous and magnesian slates; very thinly laminated, and easily frac- 
tured; colour, gray. 
45. Same as No. 44—in close proximity to a dike; metamorphosed; resembles 
very fine-grained, argillaceous sandstone ; coloured greenish yellow by oxide of 
iron. : 
46. Hornblendic rock—coarsely crystalline. 
47. Calcareous spar. 
48. Greenstone. 
49. Quartzose porphyry—contains crystals of vitreous quartz, and grains of 
chlorite (?). It resembles No. 41, but is lighter coloured, more siliceous, less crys- 
talline, and contains fewer disseminated crystals of red felspar, and more of quartz; 
has a jasperoid aspect in many localities, and in others might be taken for a meta- 
morphosed sandstone. It often bears great resemblance to the baked siliceous 
shales. 
50. Decomposing hornblendic rock, with an earthy aspect; resembling, precisely, 
burnt clay. Contains many large crystals of hornblende, from one to two inches 
ong. 
51. Siliceo-argillaceous slate—much altered by intrusive dikes. 
52. Amygdaloid. The base, which is of a dark reddish gray colour, appears to 
be sedimentary trap. It is somewhat schistose, and fractures easily. The cells 
contain green earth, calcareous spar, and zeolites. 
53. Basaltic rock—colour, black, fine-grained, homogeneous; lustre, dull; fracture 
somewhat conchoidal. 
54. Siliceous slate—highly metamorphosed; rings like phonolite when struck 
with a hammer, thinly —— prevailing colour, reddish gray; very close- 
grained and brittle. 
