1T230, 231] WAYNE COUNTY.— GRAND GULP GROUP. 147 



Orbitoides in the soft white marl intervening between the strata of rock. The 

 ledsjes of hard limestone (Nos. 3 and 4, Sec. 33) are not so wel' defined — the 

 rock being softer and whitish ; as it appears on the hillside, where the plow 

 touches it. The sandy strata (No. 6) are the same in every respect. Near the 

 top ol the hill, Dr. Miller found in his well a stratum of blue shell marl 3 or 4 

 feet in thickness, underlaid by a stratum 3 or 4 feet thick, of green laminated 

 clay. — The aggregate thickness of the calcareous Vicksburg strata, as observed 

 here, also corresponds very nearly to that deduced at Brandon from the R. Ii. 

 levelings. 



According to information given me by Dr. Miller, the same strata appear on 

 the Buckatunna, E. and S. E. of his place. Between the two streams, there 

 extends a bolt of calcareous prairie — or rather, a succession of prairie spots on 

 the ridges, where the limestone frequently crops out — characterized always by 

 Orbitoides and Peden Poulsorri, and not unfrequently, by a very large Salenia t 

 — Between this prairie belt and those extending eastward from Trotter's Plan- 

 tation and Ogburn's (1J2U9), there intervenes a belt of "hogbed soil" — formed 

 perhaps, from the clayey strata interposed between the Jackson and Vicksburg 

 Groups. 



V. THE GRAND GULF GROUP. 



230. Notwithstanding the large extent of territory represented 

 on the map as occupied by this formation, it is of less importance 

 to the district of its occurrence, than most of the formations here- 

 tofore mentioned, are to theirs. Not only is it comparatively poor 

 in nseful materials, but on the whole, it takes but a limited and 

 unimportant part in the surface conformation of the region, which 

 is chiefly due to the deposits of the Orange Sand age. Its greatest 

 development takes place on the waters of Pearl River, and on the 

 tributaries of the Mississippi ; while on the waters of Leaf, Chick- 

 asaw I my, and Pascagoula Rivers, it often requires a diligent search 

 to tletect it sit all under the heavy covering of tlte Orange Sand. 



231. Its materials are, essentially, clays and sandstones, the latter 

 generally rather aluminous and soft, and of white, grav and 

 yellowish-gray tints ; (he sand being very sharp. Beds of" loose 

 sand are unusual ; but the clays are oftentimes quite meagre, though 

 the sand contained in them (as is the case in the sandstones) is 

 usually quite fine. 



Beds of pure, highly tenacious clay are quite abundant, however, and there 

 is on the whole, little tendency to lamination ; so that, while in the Nor! hern 

 Lignitic formation, massy cl iys are the exception, they are the rule in the Grand 

 Gull siage. It is owing to this circumstance, no doubt, that the fossil remains 

 of pints, which are (ar less common in this than in the lower stages of the 

 Lignitic, are so rarely well preserved. The colors of these cla\s, also, are 

 generally much lighter than those we sec in the Northern Lignitic, being r«rely 

 other than gray, grayish- while, blue and green — the latter colors often reaching 

 a high decree of intensity; though on their surface, they olten appear yellow irom 

 oxidation. 



N. \V. of a line drawn from Fort Adams, Wilkinson count}', to Raleigh 

 Smith county, sandstones are quite abundant in this formation — rather the 

 prevale >t material. S E. of that line, however, I know of none, the several 

 kmds of clay forming the exclusive material. 



So far as I know, the whole formation from Grand Gulf and Raymond to 

 Dwyer's Ferry on the Pascagoula River, is characterized by the presence, more 



