STATE GEOLOGIST. M 



mdstone, thin bedded and quite soft, 



A F 



15 G. 

 .in shaly sandstone, passing down to a sandy shale, 

 taining much carbonaceona matter, and frith oc- 

 nal partings of a aubstanoe composed of sand, 

 claj and carbonaceona matter finely comminuted, 

 . ll-L.) 

 : Sandstone, shaly and flaggy, (645, N.) 



- mdstone, Baggy, striped with red, (545 0, and 544.) 

 Interval of 40 rods, op stn am. 



] mdstone in thin layers, (543, A — B,) 20 in. 



t Sandstone, thick bedded, mottled with red above, 



striped below, (543, C— D.) 4 ft 



4 - mdstone, with qnarta pebbles, (543, E — F ) 

 I Sandstone, thin bedded, (543, G.) 

 1 Sandstone, s -ft, very ferruginous, (543, II.) 



Interval ot ;]0 rode to collection of fragments be- 

 fore referred to. 



Prom this neighborhood to Jackson county, no outcrops of 



known : but the arenaceoUB character of the drift 



materials through Lapeer and Oakland counties and portions of 



Si Clair and Mae<>mb, renders it not improbable that the arena* 



1 strata of the Marshall and Napoleon groups would be 



found underlying that region. 



In the southern part of the State, the Marshall Group is bet- 

 ter characterized and more fully distinguished from the Napo- 

 leon Group abore. Throughout all the northern part of Hills- 

 dale county, we find a series of highly ferruginous sandstones, 

 generally. siliferous, and easily recognized. The ferru- 



ginous matter is often collected into bands of iron-stone, 

 from one-fourth of an inch to four inches thick, sometimes 

 horizontal, bi metimea oblique and Bomethnea concretionary 

 in their arrangement Prom a brick red sandstone the rock 

 t" pale red, yellowish and buff; and lower down, becomes 



yeilowiah-green, reddish-green, bluish-green and bluish. At the 

 Lowe N - well at Joneaville, it becomes a 



bluish, m' thin-bedded, ahaly sandstone, and thus pas- 



ses int<- the shales "f the Huron Group below. 



poaurOfl of the formation may be seen in the quarries 



