STATE GEOLOGIST. 91 



would, however, constitute a reversal of the general law of our 

 strata, and I have consequently been induced for the present to 

 ■ 1 the shale reached in the Saginaw deep well as the thick- 

 ened separating shale lying between the Napoleon ami Mar- 

 shall Groups. 



13. — Michigan Soli Group. 



The Napoleon Bandsl along the right bank of the 



Grand River a mile or ve Grandvilla, in Kent county 



S. E Wyoming , near the residence of Mr. Davi 



led upwards by a remarkable series of saliferous 

 shales and intercalated bedf jrpsum and magnesian lime- 



r attaining a maximum observed thickness of 184 feet. 

 The lower portion of this formation outcrops in an extensive 

 salt marsh* i I N 19 West (Wyoming, Kent county). 



This is tality ^\ tin' State salt well, near Grand Rapids. 



Nearly op] D the north aide of the river, in a bluff rising 



60 or 80 feet above the water, are located extensive gypsum 

 iuarriee. At the quarry known as licReynolda & Stewart's, 

 I ol -• ; red the followii >n: 



19. I. am. variable in thick] 



rellowish and plastic, 3 ft. 



3 ft. 



Plaster rock " — a i irregularly alterna- 



i' arenaceous limestone and Bhale, 



inclosing many d f reddish gypsum 5 ft. 



illo-arenaceous (called "Hint,").. 4 in. 



14. Shale, blue, thinly laminated, pretty uniform,. ... 4 ft. f> in. 



13. " \ ." 8 in. 



il< 1 ft. 



11. Water tin It) in 



ile, I ft. 



er rock," d of plaster, with some 



• •lav 2 ft. 



- - :; ft. 



7. Water limestone, ("which in Hovey'a quarry was 



found to pass into gypsum 1 ft. 



:; ft 



.*'. Gypsum 6 ft. 



t. Shale t la 



un, 13 ft. 6 in. 



