STATE GEOLOGIST. 139- 



(a) Lower, 51 feet: seen at most of the above localities. 

 Becomes arenaceous below. 

 12. Michigan Salt Group, 184 feet: 



(c) Carbonaceous and argillaceous shalc^gypseous and pyri- 



tous marls. 

 (6) Shales, marl, magnesian and silicious limestone, and 

 thick beds of gypsum. The shales impregnated, with 

 salt. 

 ; (a) Saliferous shales and alternating arenaceous limestones. 

 1.1. Napoleon Group, 123 feet: 



(<f) Shaly micaceous sandstone, 1 5 feet. 

 (c) Kapoleon sandstone,, 18 feet, highly saliferous in many 

 localities; Napoleon, Grandville, Eush lake, Pt. aux 

 , ,. Barques. , 



(&) Shaly micaceous sandstone, 15 feet: Salt borings. 



(a) Clay or shale, 15 feet, [more than 64 feet at East Sagi- 



naw (?) ] 



III.— DEVONIAN SYSTEM. 



10. Marshall Group,. (Chemung,) 159 feet: 



(c) Eeddish, yellowish and greenish sandstones, 147 feet: 

 Marshall, Jonesville, Hillsdale, Battle Creek, Holland, 

 Pt. aux Barques. 



(6) Shaly micaceous sandstone, 10 fe,et: Jonesyille, &c. 



(©) Conglomerate, 2 ft. : Grindstone Quarries, Pt. aux Barques. 



9. Huron Group, (Portage), 224 feet: 



(<£) Find "bluish gritstones, 14 feet: Pt aux Barques. , 

 (c) 'Shales, limestones and flagstones, 18 feet. The Kidney 

 Iron clays of Branch county are supposed' to belong 

 here. 'Shore of Lake Huron, below Pt aux Barques; 

 Branch, Calhoun, Kalamazoo and Lenawee counties. 



(b) Green shale, 10 feet: Grand Traverse Bay. 



(a) Black bituminous shale, 20 feet; Sulphur Island, Squaw 



Pt , Grand Traverse Bay. 



8. Hamilton Group 55 feet: 



(c) Crystalline limestone, with included lenticular clayey 



masses, 23 leet: Partridge Pt., Little Traverse Bay. 



(b) Argillaceous limestones, eminently fossiliferons, wilh al- 



ternating shales, 17 ft.: Partridge Pt., Little Traverse 

 Bay. 

 (a) Black bituminous limestone, 15 feet: Carter's quarry, 

 near Alpena; Thunder Eay Island, Little Traverse 

 Bay. 



7.;JUpper He'djiberg Group, 354 fee',: 



