293 



The following table will exhibit the order and succession of the seT- 

 eral strata, so far as could be determined, in descending order. 



Surcession of Rock Strata, in Hilhdale couvty, occupying the South- 

 ern, border of the Coal Basin of Mich? ff an, below the Coal Beds. 



2. 

 3. 



4. 

 6. 



6. 



7. 

 8. 



Coarse, quartzose, yellowish gray sand rock; occupying ele- 

 vated sides of knolls. A good material for grindstones, 



Ash colored or brown sandiock, sometimes contains fossils, 



Dingy green, fine grained, strata. Occasional fossils, and 

 with yellow ferruginous spots 



Hard gray stratum of sand rockrock, 6 inches to 



Dingy green, ^ne. grained, inte •stratified with slaty sand 

 stone, and apparently with blue clay shale, 15 to . 



Yellow, fossiliferons sandrock. Abounds in marine fossils, 



Oreen, tine grained, sand rock ; perhaps 



Clay and ironstone, 



The stratum designated as yellow, fossiliferous, is remarkably well 

 characterized, being almost a peifect Cijngeries of fossils. The whole ia 

 of a deep brownish yellow, and sometimes a buff color. The same stra- 

 tum is met with, as appears by the notes of Mr. Douglass, in tracing 

 down the western side of the basin, in the banks of Kalamazoo river, in 

 Calhoun county, and at a level two hundred feet lower than the same 

 rock in Hillsdale. This difference in level, shows a dip northerly not ex- 

 ceeding six minutes of a degree. But this result may be considered as 

 less than the actual amount, from the fact of the two points not being 

 in the true direction of the dip. 



No stratum precisely analagous to this has been mentioned in the re- 

 ports on the corresponding formations of the adjoining States. 



By reference to the general topography of the State, it will be seem 

 that the extreme southern termination of the sandstone series, has am 

 elevation several hundred feet higher than any other part of the basia 

 yet examined. This may account for the superior thickn oss and inclin- 

 ation of the rocks at this point, and for the circumstance of the claj 

 and ironstone making its outcrop here. In consequence of the greater 

 uplift at this point., several of the series are brought to the surface, 

 which elsewhere are entirely concealed, owing to their more nearlj 

 horizontal position. 



Mo>t of the sandstones have been used for ordinary building purpo- 

 ses. The coai-se grained rock (No. 1) is usually found eligibly situa- 

 ted for quarrying, and is well adapted both for building and grind- 



