238 TUE MAIIQIJETTB lEOX-BEAEING DISTRICT. 



Mount Oiiiinii, t\w wiudiny.s of which serve beautifully to show the minor 

 folding of the formation. 



Migisi Bluffs. — Across a transverse depression west of ]\Iount ChocolaA', in 

 the nortli part of sec. 1 and in sec. 2, T. 47 N., R. 25 W., are the Migisi Bluffs 

 (Atlas Sheet XXXIX). The eastern ])art of these bluffs is, in a large way, 

 a westward-plunging svncline, but, as in tlie case of JMount Chocolav, this 

 larger svncline is found to be composed of many subordinate rolls. The 

 depression se])arating Mount Chocolay and the Migisi Bluffs is, then, the 

 bridge or anticline of a large north-south fold. The complex, plunging Migisi 

 syncline may, then, be considered as a cond)ined effect of folding in two 

 directions. The eastern part of the liluffs is composed of the quartzite, 

 but, as a result of its western pitch, the Koua formation appears in the 

 eastern half of sec. 2 in a series of fingers, each of wliich corresponds to a 

 minor fold. These fingers unite toward the west and form the broad belt 

 of the Kona formation. Beginning at the north and going east and south 

 around the bluff, the strike changes from an east direction to a southeast, 

 then to a south, then to a southwest, and finally to a western course on the 

 southern side of the fold. As in other localities, separating the quartzite 

 and the Kona dolomite is a thin belt of slate, which becomes calcareous in 

 its upper parts. As on Mount Chocolay, the naiTow belt of ferruginous 

 conglomerate, bearing numerous pebbles of chert and jasper, is of great 

 assistance in following the details of tlie minor folds. In the nortli part of 

 sec. 2 appear the green scliists of the Archean, and a section through the 

 western part of the Ijluffs shows the complete succession from the Archean 

 to the Kona dolomite. 



On the southeastern slope of the Migisi Bluffs, north of the quarter 

 post between sees. 1 and 2, near the section line, mav be seen the actual 

 contact of the quartzite and granite-gneiss. As the bottom of the quartzite 

 is approached there appears a bed of conglomerate 8 or 10 feet thick, 

 containing numerous white quartz pebbles, some of them 8 inches across. 

 Toward the south, near the base of a cliff, the exposure becomes less 

 conglomeratic and ciianges into a schistose rock. This clearly fragmental 

 schistose rock is in dii-ect conJ-ict with another schistose rock, which can be 

 traced l)y gradations into the genuine granite-gneiss. There appears to 



