12 Sketch of the Geology of the Arctic Regions. 



lat. and 65° and 125° W. long, has been arranged by Prof. Jame- 

 son, from the actual inspection, it is believed, of specimens brought 

 from those countries by the expeditions under Capt. Parry. 



Primitive Rocks. 



Granite, gneiss, mica slate, eurite porphyry, hornhhnde, hornblende 

 slate, primitive greenstone, and primitive limestone. 



1. Granite. — Minerals imbedded in granite. Rose quartz, ac~ 

 tynolite, epidote small yellowish green crystals, precious garnet of a 

 columbine red color and transparent, chlorite, schorl, minute crystals 

 of beryl, coccolite, zircon, graphite or black lead, specular iron ore, 

 iron pyrites. 



2. Gneiss. — Color red and grey, fracture sometimes coarse and 

 granular, sometimes fine and slaty, most abundant of all the primitive 

 rocks in the arctic countries. Minerals imbedded in gneiss. 



Beautiful precious garnets, and hyacinth red garnets. Rich veins of 

 red quartz traverse the gneiss, aud amorphous masses lie around. — 

 Actynolite, graphite, magnetic and common iron pyrites. 



3. .Mica Slate. — This is a compound of mica and quartz, and 

 forms beds subordinate to the gneiss. The minerals imbedded in 

 this rock, are hornblende, actynolite, tremolite, precious garnet, rock 

 crystal, common iron, and magnetic iron pyrites. 



4. Clay Slate, — Less frequent than mica slate, contains imbedded 

 iron pyrites. 



5. Chlorite Slate. — Imbedded in this rock are found actynolite, 

 hornblende, felspar of a red color, indurated talc, massive common 

 chlorite, calcareous and rhomb spar, precious garnet, octohedral crys- 

 tals of magnetic iron ore, red iron ore, iron pyrites. 



6. Hornhlende. — This mineral occurs in beds and also associated 

 with felspar when it is called greenstone. The imbedded minerals in 

 these rocks are felspar, mica, chlorite, actynolite, quartz, diallage, 

 common iron, and magnetic iron pyrites. 



7. Serpentine. — Colors dark leek green, and greenish black, the 

 lustre glimmering, fracture splintery, or splintery conjoined with con- 

 choidal, more or less translucent. The following imbedded minerals 

 were found in these rocks. Brown diallage, glassy actynolite, fibrous 

 greenish grey talc, flexible asbestus, rhomb and calcareous spar, 

 chromate of iron, magnetic iron ore, and iron pyrites. 



