of the United States, 41 



Mineral Contents. In some situations it contains large 

 quantities of iron pyrites. 



Springs. The water yielded by this formation is very 

 unheahhy, and in many situations the scarcity of it presents 

 a serious impediment to cultivation ; in Alabama they have 

 sunk in this stratum three hundred feet to find good water, 

 but have not succeeded in penetrating through the limestone. 



Geographical Extent. It commences at the Eutaw springs 

 near Santee river in South Carolina, passes to Orangeburgh, 

 and crosses the Savannah river fifteen miles below Augus- 

 ta, occasionally disappearing under the sand. 



It may then be traced to Burke County in Georgia, 

 crosses the Ogeechee near Louisville; then near Sanders- 

 ville, passing through Wilkinson County ; it is theji found 

 at St. Mark's in Florida, where the tower and fort are built 

 of this limestone. The basis of the land forming the north- 

 east boundary of the Sea of Mexico, is composed of it; 

 from thence to Alachua plains, crossing the Apalachacola, 

 and proceeding in a north-west direction across the head of 

 the Choctaw creek, it meets the Alabama river near Ca- 

 hawba, where this formation expands, and forms a basin 

 one hundred miles square, comprising the counties of 

 Montgomery, Dallas, Wilcocks, Greene, Marengo, and 

 part of Washington, in the State of Alabama. On many 

 parts of the surface in these counties, there is a rich loam ; 

 but the limestone is so near the surface, and water so scarce 

 and bad as to present many difficulties to the cultivator. 



It then passes north-west, by Demopolis, a French set- 

 tlement, to the Chickasaw country, where it terminates near 

 the bluffs ; in this situation, for many hundred square miles, 

 the ground is white with the detached oyster shells, which 

 have been bleached by exposure to the weather. 



6. Upper Marine Formation. 



In Europe one part of this is usually distinguished by 

 large tracts of sands, which not only afford no return to the 

 farmer, but rebel against his dominion, and destroy his im*- 

 provements. 



The sands of Norfolk, Pomerania, Ostend, Bayonne and 

 Bordeaux belong to this formation. On the south-west 

 coast of France, hills of sand advancing like an enemy upon 



VoL.VU.— No. 1. G 



