310 THE MARQUETTE IRON-BEAEING DISTRICT. 



resultiug; in the second, shattering. These phenomena are best seen in 

 the NW. 4 sec. 28, especially along the southwestern slopes of the bluffs; 

 and a still further complication is here found, since apparently the true 

 Archeau schist does appear at one place below the quartzite-conglomerate. 



It is possible that in the Ajibik Hills there are small areas of the 

 Goodi'ich quartzite which, as a consequence of the removal by erosion of 

 the Negaunee formation, were deposited upon the Ajibik quartzite. This is 

 suggested by certain little-mashed quaiizite exposures, which contain jasper 

 pebbles. Bvit in no case could such suspected later quartzite be certainly 

 discriminated from the Ajibik quartzite ; so all are mapped as belonging 

 to the older formation. 



To give the microscopical characters of the different phases of rocks 

 on the Ajibik Hills would be practically to repeat the general description 

 (pp. 289-294), as nearly all phases of the formation are here found. 



Goose Lake. — Eastward along this belt the next bunch of ledges found is 

 south of the southeast arm of Goose Lake, in sees. 23 and 24 (Atlas Sheet 

 XXXV). The quartzites are luiderlain by the Wewe slates, and between 

 are the transition forms. The quartzites suffered great deformation, and 

 consequently little-altered quartzites are rare, and the cherty quartzites, 

 quartz-rocks, and quartzite-breccias are particularly^ abundant. The veins 

 in this area are unusually large and numerous, and they are filled to more 

 than a usual degree by secondary hematite and magnetite. The lai'ger 

 of these veins and the most brecciated phases of the quartzites simulate 

 ferruginous chert or jasper, and the abundance of iron oxide has led to 

 prospecting in a number of localities. 



In the northeast part of sec. 24, surrounded on three sides by the 

 Wewe slates, is a great ledge of quartzite, precisely similar to the ledges 

 :southwest of Goose Lake. Here, however, are particularly well seen the 

 interstratifications of the slate and quartzite and the different manners in 

 wdiich the folding affected the vitreous rock and the slates. The folded 

 Wewe rocks passed into mica-slates, with a nearly vertical cleavage, which 

 stops abru})tlv upon reaching the quartzite layers. These quartzites were 

 shattered and cemented by quartz and iron oxide. 



Cascade area. — Passiug to the southcm belt of the Ajibik quartzite, we 

 find numerous exposures at various points from the northwest part of 



