williams. 1 STRATA IN MICHIGAN. 175 



or paleontologically, even in Ohio ; still less in the States farther west. 

 In each case it is a comparison of allied but dissimilar series. 



The Catskill and Conglomerate problems are discussed in a former 

 chapter. Some of the problems associated with the Kinderhook and 

 Chouteau groups have been considered in the chapter on the Missis- 

 sippian series. In the present chapter I propose to consider the prob- 

 lems associated with the correlation of the Waverly, the Marshall, the 

 " Black shale" and the Gouiatite limestone formations, and secondarily 

 the Kinderhook and Chouteau. In the first chapter is discussed the 

 development of opinions and nomenclature concerning these formations 

 up to 1843, and in the chapter on the general correlations of the forma- 

 tions westward from New York to the Mississippi Valley, this devel- 

 opment is traced onward to about the year 1851. 



The succession of strata in Michigan as published in 1838-'41, ar- 

 ranged in descending order, as compiled from Dr. Houghton's Annual 

 Keports, is as follows : l 



XXXI. Recent Alluvium. 

 XXX. Ancient Alluvium. 

 XXIX. Erratic Block and Diluvium. 

 XXVIII. Tertiary Clays. 

 XXVII. Brown or gray sandstone. 

 XXVI. Argillaceous iron ore. 

 XXV. Coal strata. 

 XXIV. Red or variegated sandstone. 

 XXIII. Gray or yellow sandstone. 

 XXII. Shales and coal, Lower Coal Measures. 

 XXI. Blue compact slaty sandstone. 

 XX. Gray limestone or upper lime rock. 

 XIX. Fossiliferou8 ferruginous sandstone. 

 XVIII. Kidney iron formation. 3 

 XVII. Sandstone of Point aux Barques. 

 XVI. Clay slates and flags of Lake Huron. 

 XV. Point au Grcs and Manistee limestone. 

 XIV. Soft, coarse-grained sandstone. 

 XIII. Black bituminous, aluminous slate. 

 XII. Limestone of Lake Erie. 



D. Corniferous limestone ; C. Thunder Bay and Little Traverse Bay 

 limestone (/-a) ; B. Black bituminous limestone; A. Blue limestone. 

 XI. Mackinac limestone. 

 X. Polypiferous portion of Upper Limerock. 

 IX. Pentainerus portion of Upper Limerock. 

 VIII. Lower limerock and shale. 

 VII. Sandy limerock. 

 VI. Upper gray sandstone. 

 V. Lower or red sandstone and shale. 

 IV. Mixed conglomerate and sandstone. 

 III. Conglomerate. 

 II. Metamorphic rock. 

 I. Primary rocks. 



1 First Biennial Report of Progress of the Geological Survey of Michigan, etc., Lansing, 18G1, pp. 12; 

 13, 14, 15. 

 * la this classification No. XVIII is made the lowest hed of the Carboniferous. 



