*[25, 20] CLAY OP THE ORANGE SAND. 15 



25. Very commonly, however, clay deposits occur near to the 

 contacts of the Orange Sand with underlying- clayey formations : 

 and then the shape of the mass conforms, more or less, to the 

 surface of the latter : though stratified horizontally. In these 

 cases, the Orange Sand clay is oftentimes but little different from 

 that of the more ancient formation from which it lias obviously 

 been derived, though redeposited in evident stratigraphical and 

 lithological connection with the Orange Sand. 



26. The general character of the clays properly belonging to 

 this formation, is that of meagre pipeclays of great plasticity, 

 requiring but little seasoning before they are worked ; wherein 

 they differ essentially from the fat, intractable clays of some of the 

 underlying formations. Like all other materials of the Orange 

 Sand, they are remarkably poor in lime and magnesia. As to 

 their color, it is a singular fact that but few of them are strongly 

 ferruginous. Grayish yellow, cream-color, white, and purple, are 

 the usual tints ; the latter rarely occurs throughout large masses, 

 but very frequently in layers and stripes within masses of other 

 colors ; and its various shades, contrasted with the other hues 

 mentioned and an occasional bright yellow, crimson, or blue stripe 

 or dot, give rise to very unique and beautiful colorings. The red 

 ochre tint of the red clay deposit found in Tishomingo, is rather 

 unusual. A great variety of colors is sometimes met with in the 

 small nodular masses which frequently occur in the southern part 

 of the State, mostly associated with gravel deposits, and themselves 

 apparently representing pebbles — since the stratification lines 

 which they often exhibit, appear to be entirely independent of those 

 of the Orange Sand deposits. 



The clay which composes these nodules cannot, however, be identified with 

 that of any of the older formations of the State, unless indeed, we imagine them 

 to have been deprived of their carbonaceous coloring matter, and their protoxide 

 of iron transformed into peroxide — a kind of metamorphosis which, as will be seen, 

 appears to be common, with some others, in the Orange Sand formation. It is 

 indeed, but very rarely that we find in this formation, under ordinary circum 

 stances, anything that allows of farther oxidation by atmospheric influences. I 

 know but one instance in which a very dark colored clay, containing a large 

 amount of oxidizable matter occurs within the Orange Sand proper, though at a 

 great depth below the surface ; and even in tins case, the oxidation has penetrated 

 several inches into the mass, which is very dense. 



