Winchell.] '^ [March 5, 



B, In Western New York. 



1. Portage Sandstone, thick bedded. 



3. Oardeati. Shales and Flagstones — green and black — slaty and sandy- 

 shales with thin layers of sandstone. 



3. (JasTiaqua Shale— soft, argillaceous, green, crumbling to a tena- 

 ceous clay. 



In Ontario, although Professor Hall and Sir William Logan have 

 assigned at least a portion of the black shales to the horizon of the Por- 

 tage Group, I have not been able to distinguish any of them from the 

 Genesee shale proper containing Leiorhynchus muUicosta and Discina Lo- 

 densis. As overlying shales of the age of the Portage Group however 

 exist in Michigan close to the national boundary, I have always pre- 

 sumed that they extend across it. This opinion Dr. Hunt has very re- 

 cently confirmed. 



In Michigan I have been able to make out a complete determination of 

 the strata as follows i^^ 



Parma Conglomerate : — a whitish or rusty, often congiomeritic and ob- 

 liquely laminated sandstone with vegetable remains. 105 feet. 

 Carboniferous Limestone : — irregularly bedded, often clierty or ferrugi- 

 nous, and much shattered in sitv, — becoming arenaceous below. 70 feet. 

 Michigan Salt Group : — consisting of aluminous and gypseous shales, 

 thin gray flags, bands of limestone and thick beds of gypsum. 200 feet. 

 Marshall Group: — consisting of: — 



Napoleon Sandstone, pale buff, often congiomeritic, obliquely lami- 

 nated, thick bedded. 123 feet. 

 Marshall Sandstone, reddish, yellowish, olive, obliquely laminated, 

 highly ferruginous — the iron often under a rudely concentric, concre- 

 tionary arrangement. In places calcareous. Highly fossiliferous. 

 160 feet. 

 Huron Gritstones, bluish or greenish gray, fine grained, regularly 

 bedded. 15 feet. 

 Huron Group, consisting of : — 



Argillaceous shales and flagstones — the latter less prominent in the 



southern part of the State. 500 feet. 

 Green arenaceous shales, especially in Grand Traverse Bay. 25 feet. 

 Black bituminous shale (Genesee shale). 25 feet. 

 Hamilton Group. [The calcareous member of this group is conspicuous 

 in Michigan.] 



In the State of Ohio the succession of strata seems to be nearly as fol- 

 lows :^^ 

 Conglomerate, huffish, obliquely laminated, more or less pebbly, often 



with rudely concentric spheroids of iron ore. Sometimes underlaid by 



"False Coal Measures.'* 



92 Mich. Geol. Rep., 1861, p. 138; Amer. Jour. Sci. [2j xxxiil., 352; The Grand Traverse Region, 

 p. 49. 



"^ Foster Geol. Rep. Ohio, p. 77; Briggs— lb., p. 79; Whittlesey— Proc. Amer. Assoc, v. p. 76; 

 ■VVincliell— Mich. Geol. Rep., 1861, p. 78, also, Prospsctus, Nefl' Petroleum Co., p. 7. 



