112 REPORT OF THE 



6. The arenaceous character of the lower part of the forma- 

 tion, becoming on the Charity Islands, a thick mass of yellow- 

 ish sandstone ; the blotches and disseminated particles of 

 greenish matter found here ; the frequent shaly partings of the 

 strata; certain "vermicular ramifications" upon the bedding 

 surfaces, all recall the characters of the upper part of the 

 Warsaw Limestone. 



1. At the same time, the portion below the ferruginous are- 

 naceous bed abounds in geodes filled with crystals of calc spar, 

 dog-tooth spar, pearl spar, selenite, anhydrite, pyrites, &c, which 

 recall the " Geode Bed," below the Warsaw Limestone. 



Whether our formation possesses real affinities with all the 

 groups from the "geode bed" to the Kaskaskia limestone, is an 

 interesting question which probably we shall yet be able te 

 resolve. Such a result would not be surprising. The various 

 groups of the Silurian and Devonian Systems, stretching 

 through a vertical thickness of many thousand feet in New 

 York and Pennsylvania, are all faithfully represented within 

 the space of as many hundred feet in the Lower Peninsula of 

 Michigan ; and we are prepared to foresee that our situation, 

 similarly, upon the borders of the great carboniferous sea, has 

 resulted in an attenuated representation of the various groups 

 of the carboniferous limestone, which towards the south-west 

 thickens up to some thousands of feet. 



15. — Parma Sandstone. 



In the townships of Parma, Sandstone and Springport, in 

 Jackson county, is found a white, or slightly yellowish,«quartz- 

 ose, glistening sandstone, containing occasional traces of ter- 

 restrial vegetation. On the line between sections 18 and 19, in 

 the township of Sandstone, this rock is seen succeeding upwards 

 to the furruginous bed of the Carboniferous limestone. On the 

 N. W. \ of N. W. \, sec. 29, at the quarry of Mrs. Titus, the 

 sandstone presents a characteristic exposure. The rock is 

 light-colored, thick-bedded, firmly cemented and appears to 

 furnish an excellent article for building purposes. - It presents 



