GEOLOGICAL EXPLORATIOXS AND LITEKATUKE— 18S1. 87 



sections are descriheil across tlu- I'oriuatiou. Tliev are so nearl\- alike in 

 general features that we need refer to only two of them in this place. In 

 particulars, however, they vary widely. 



Tlie ({itartzites of the Mesnard rang-e, near Marquette, are iuterhedded 

 with arg-illites and liydromicaceous* schists or slates, and with ferruginous 

 and siliceous slaty seams, all dipping south nearly vertically. Conformably 

 superimposed u])on the quartzite is a series of siliceous limestones, inter- 

 laminated with li: nils of novaculitic slaty seams of a purplish color. The 

 limestone is folded and corrugated. Farther south (juartzites again appear, 

 and, following these, a baud of conglomerate inclosing (juartzite pebbles and 

 novaculitic schistose fraguieuts, which "are cemented together by a paste 

 of similar schistose material, and intermingled with quartz-sand and octa- 

 hedric crystals of inartite." South of the conglomerate 1)elt is a recurrence 

 of the entire series, but in reversed order, though the dip continues to be 

 southerly. 



At the west end of Teal Lake is another wide exposure of <|uartzites, 

 whose description, given in the author's words, will express his notion of 

 the relation of the "quartzite group" to the underlying dioi-ites: 



Large ami very iustructive exposures of the quartzite fonnatiou and of its 

 conuectiou with the underlying dioritic series are observable at the west end of Teal 

 Lake. The south slope of the hilLs is formed by a thick belt of compact, heavy- 

 bedded, whitish quartzites, which project iu long rock walls, dipping southward 

 under an angle of 0.5° to 70O; north of this belt we find dark-colored slaty rocks 

 richly impregnated with minute crystals of martite in connection with seams of lighter 

 colored, not ferruginous, argillitic or novaculitic schists, amounting to eonsidcrable- 

 tbickness; another thick body of quartzite ledges follows on their north side, which 

 forms the edge of the northern slope of the hillside, on which a descending section 

 through the lower portion of the formation down to the dioritic series is well exposed; 

 novaculitic seams alternating with bauds of quartzite form the upper part of the 

 slope; beneath them follows a large succession of silky, shining, hydromicaceous 

 slate-rocks, with a crystalline, granular, aluminous groundmass in different shades of 

 color, and in some of the seams charged with large proportions of granular crystals 

 of martite and magnetite. These slaty rock-beds are on their north side conform- 

 ably adjoined by chloritic and dioritic schists with inclosed massive diorite belts, 

 which rock series composes all the hill ranges farther north to the valley of Carp 

 Elver and those on the north side of the valley. (P. 45.) 



