308 THE MARQUETTE lEON BEARING DISTRICT. 



.examination of the thin sections of the basal conglomerates, described on 

 page 292, confirms the conclusion that the mud was but slightly compacted 

 .at the time it yielded fragments to the Ajibik quartzite. The outlines 

 of the pebbles are minutely irregular, the projections filling the spaces 

 'between adjacent fragmental quartz grains and thus contrasting with the 

 clean-cut forms of well-indurated waterworn pebbles. 



Large exposures of the Ajibik formation occur in sees. 11 and 12, 

 T. 47 N., R. 26 W., and on both sides of the northwest arm of Goose Lake 

 (Atlas Sheet XXXIV). These ledges are all rather pure, fresh-looking 

 quartzites. 



The foregoing series of ledges connecting Goose Lake and Teal Lake 

 are all in the eastern part of the great westward-plunging syncline, where 

 the minor plications are slight. Corresponding with this in thin section, we 

 find the normal phase of quartzite to be the \mve enlargement kind, although 

 secondary independent quartz was also deposited in the interstices. While 

 the dynamic effects are slight, nearly all of the quartz grains show undula- 

 lory extinction, and many of them are distinctly fractured. 



wewe Hills — The ucxt largc bunch of exposures is in sees. 22 and 23, 

 T. 47 N., R. 26 W. (Atlas Sheet XXXV). The northernmost of these ledges 

 .are similar to those just described. The large exposures in the southeastern 

 part of this area constitute a westward-plunging, isoclinal, synclinal fold, 

 and, as a consequence of this, many of the quartzites become sericitic, cherty, 

 and vitreous, and some of them schistose. At certain places along the south 

 border of this set of ledges the rock is a distinct reibungsbreccia which 

 closely simulates a conglomerate. Indeed, this breccia was at first taken 

 for a basal conglomerate resting upon an older rock. A closer examination, 

 however, showed that while many of the fragments have been shattered in a 

 spheroidal manner, many others are angular or subangular, and all are similar 

 to the adjacent phases of quartzite. As usual, these breccias are cemented 

 with vein quartz, cherty quartz, and the oxides of iron. The latter are 

 naturally more abundant in the matrix than in the fragments, thus giving 

 to the former a dark color in which the fragments stand out sharply. 



Ajibik Hills. — The next great ledges, mainly in sees. 27, 28, and 29, 

 ■T.47 N., R. 26 W. (xitlas Sheets XXXII and XXXV), are the Ajibik Hills, 



