1(34 GEOLOGICAL REPORT. [1T271, 272, '11'), 274 



thus far Uave been unable to ascertain the dimensions of the 

 bed in place. Between the Jackson and Vicksburg beds, the 

 only deposit 1 know is that at Vicksburg (\220). The 

 thickness of the bed, according to Prof. Moore's observations, 

 does not exceed three feet ; yet, from its favorable loeation on the 

 banks of the Mississippi River, it might be made available, if it 

 should prove of good and uniform quality. Of this, not having 

 examined the Jed, I am unable to judge.— On the whole, lignite 

 is not to be looked for in extensive deposits, on the territory 

 embraced by the marine calcareous formations, indicated on the 

 map, bj the several shades of blue. 



271. Upper or Southern Lignitic. — Lignite deposits are much 

 less common on the territory of this formation, than on that of 

 North Mississippi. 



I have had no opportunity of examining outcrops or even specimens of lignite 

 from these strata. The localities mentioned in 1 234> in Hinds an! < Haiborne ; 

 abed occurring near Jud; Franklin county (1!~29G and ff.) and 



another in W. Lawrence, whose precise location I have been unable to . 

 tain — are the only instances I know of the occurrence of lignite on the territory 

 of the Grand Gulf Group. 



272. Of the useful Clays of the Lignitic formations, 1 

 already spoken, as far as may at present be necessar; ful, in 

 connection with those of the Orange Sand. The variety and 

 abundance of these materials is very great, and they will no doubt 

 be appreciate'! hereafter. 



273. It may be proper to mention in this place, some local occurrences of use- 

 ful deposits of the indurate clay or siliceous claystone, which sometimes, as has 

 been mentioned (;l(i.j), is found associated with, or rather subordinate to, the 

 Flatwoods Clay. Generally, this rock forms small, irregular, lenticular masses, 

 or veins, and is often very hard. It seems that in S. E. Tippah, large masses of 

 this rock have been found, in a locality which I have not precisely, 

 by a relative of S. R. Spight, Esq., of Ripley, The rock somewhat resembles, 

 in color and appearance, lithographic st ne, for which it was at first mistaken ; 

 it will not, of course, serve the purpose, since it is not attacked by acids. It 

 assumes a good polish, however, and as it is somewhat variegated, it might sub- 

 serve ornamental purposes, if found in sufficient quantity. 



A similar rock, but a good deal softer, so as to absorb water greedily, has been 

 found in Choctaw county, on S. 23, T. 18, R. 10 E., by Mr. A. .1. Worsham. It 

 attracted attention by the adaptedness of its powder for polishing metals with- 

 out scratching, even when it had only been scraped off with a knife, without fur- 

 ther pulverization. The rock would be admirably adapted to hone.-, but for its 

 absorbent power, which renders it necessary to saturate the whole slab with 

 water or oil before using. Varieties of this rock not possessing this fault, may 

 perhaps be found in the region. It occurs in small slabs or plates, shewed on 

 the hillsides, where its stratum is. according to description, overlaid by 

 twenty feet of sand. 



MINERAL FERTILIZERS OF THE TERTIARY FORMAT* 



274. Ferruginous Green-sand of the Claiborne Group — Shon 

 Greensand. — The highly ferruginous sand occurring in the rail- 

 road cut at Vaiden Station, near Shona:alo, ('a- roll county, and 



