NATURAL SCIENCES OF PHILADELPHIA. 13 



8. Clays of red or brownish colors above ; blue and green below 3| 



9. Deep brown clay, with rugged concretions of same color ... 3 



10. Hard light bluish limestone, with some rather large columns of 



Crinoids, Choneles, Vernez/iliana, Sfc 2J 



11. Brown, ash colored, and blue laminated clays, which are more or 

 less arenaceous, with near the middle some 5 or 6 inches black shale 46 



12. Gray and purple argillaceous limestone, with Pinna, Productus, 

 and a few Fusulina 1^ 



13. Green laminated clay 4 



14. Two or three layers of soft fine grained sandstone, more or less ar- 

 gillaceous, and separated by seams of clay 2 



15. Bluish and ash colored clays 21 



16. Alternate layers of hard bluish gray limestone, and seams of clay 

 with sandy concretions 3 



17. Rather hard yellowish limestone, with Fusulina 2 



18. Ash colored clay, not very well exposed 15 



19. Yellowish impure limestone with Fusulina 2 



20. Ash colored laminated clays above the creek 5 



About three hundred yards below where this section was taken, the creek 



was observed to fall nearly a foot, over a ledge of hard limestone ; and one 

 mile further down, the bed of the creek is composed of a hard yellow lime- 

 stone containing great numbers of Fusulina. At these localities Mill creek is 

 probably not elevated more than thirty feet above the Kansas. 



Near half a mile east, or south east, of the point where the Fusulina lime- 

 stone was seen in the bed of Mill creek, and at a somewhat higher elevation, 

 we saw apparently the same bed of Fusulina limestone showing a thickness of 

 three feet. Under this there was at one place exposed a thickness of some 

 four or five feet of very fine yellow sandstone with minute specks of Mica. 

 These exposures indicate a moderate dip of the strata towards the west or 

 north west. 



On the north side of Kansas, in a direction a little west of north, and about 

 sixteen miles from the last mentioned localities, we observed an outcrop on a 

 small stream marked " Last Creek" on the maps, presenting the following sec- 

 tion, descending : 



Feet. 



1. Seams yellow magnesian limestone, alternating with clay, showing a 

 thickness of about 8 



2. Yellow soft granular magnesian limestone, containing Productus Nor- 

 woodi, and an undetermined species of Myalina 4 



3. Fine laminated black shale 1 



4. Gray rather soft argillaceous limestone 1 



5. Blue somewhat indurated very fine calcareous clay containing at its 

 junction with the next bed below, Chonctes, Synocladia biserialis, Chcstetes, 

 and fragments of Crinoids 9 



6. Seams hard, compact gray limestone, alternating with softer argillo- 

 calcareous matter, and containing casts of many small Cypricardia-like 

 shells, small Murchisonia, Pleurotomaria, Macrocheilus, Naticopsis, Bcllero- 

 phon } &c 2 



7. Bluish laminated clays weathering to drab color 4 



8. Yellow rather soft granular magnesian limestone, with embedded 

 fragments of harder more compact do o 



9. Bluish indurated calcareous clays 3 



The base of this section is evidently not elevated much above the Kansas, 



as it extends down to the bottom of a deep ravine formed by the creek, while 

 its top appeared to be nearly on a level with the surface of the bottom prairie in 

 the Kansas valley. These beds dip a little to the north west, and are very si- 

 milar, especially the magnesian limestones, to some of the Permian strata hold- 

 ing a position far above this in the series, some considerable distance west of 



1859.] 



