THE KOXA DOLOMITE. 253 



INTERESTING LOCALITIES. 



Nearly all of the jjeculiarlties of the Koua dolomite mentioned in 

 the general description may be found at any of the localities in which the 

 exposm-es are extensive, so that here there will be given but little more 

 than a list of localities in which the exposures are numerous, to serve as 

 guides to those wishing to study this formation. 



Eastern area. — Beginning at tlic uortliwest, there are excellent exposui-es 

 near tlie old Morgan Furnace, in the north part of sec. 31, T. 48 N., R. 25 W. 

 (Atlas Sheet XXXVI). Numerous large exposures occur on the bluff 

 south of Mud Lake, in sec. 32. The south half of Omimi Bluff, in sec. 34, 

 also gives very numerous expo.sures (Atlas Sheet XXXVIII). On Mount 

 Mesnard, as has been said, the crowning peak is a closely compressed 

 syncline of the Kona dolomite. The central and higher part of Mount 

 Chocolay, south of Marquette, is another syncline of the dolomite. On the 

 Migisi Bluffs (Atlas Sheet XXXIX), in sees. 2 and 3, T. 47 N., R. 2.5 W., 

 are very numerous large exposui'es of the dolomite. On account of the 

 western pitch this formation ends at the east in a series of fingers, the gen- 

 eral syncline, as has been said, being composed of minor synclines. The 

 succession of the members of the formation, the dynamic effects produced 

 by the folding, and the slate marking the transition belt between the dolo- 

 mite and the Mesnard quartzite may be particularly well observed here. 

 The hills often break off in eastward-facing cliffs, and by following from the 

 north around the east side to the south side of such a bluff one continues 

 parallel to the changing strike of the terminating layers. Both east and 

 west of Tigo Lake (Atlas Sheet XXXVII), in sees. 4, 5, 8, and 9, T. 47 N., 

 R. 25 W., are verj^ numerovis exposures of the dolomite. 



Ragged hills. — Numerous typical exposures of the formation are found on 

 all the bluffs in sees. 7, 8, 17, and 1 8, T. 47 N.,R.25 W. (Atlas Sheet XXXVII). 

 On the south slope of the bluff in the SW. 5 sec. 17 is a belt of cherty^ 

 quartzitic breccia, which on its weathered surface very closely resembles a 

 conglomerate. This breccia contains fragments of slate, quartzite, chert, and 

 marble. It is underlain by folded beds of marble, the minor sinuosities of 

 which are truncated by the breccia, and it is overlain by quartzite At first 



