^121, 122] ROTTEN LIMESTONE — PONTOTOC — CHICKASAW. 79 



Bdemnitella mucronata, Baculites gigas ; numerous small Inocerami. — Not far 

 from (N. W. of) this locality there is a well (Nelson's) 330 feet deep. Wells 

 decrease in depth pretty regularly from here eastward to Carrollville, owing, 

 however, not only to the dip of the strata, but also to the descent from the 

 ridges on which these wells arc situated. Lower down, Tishomingo Creek 

 shows outcrops of the common Rotten Limestone, while the same material seen 

 at the bluff near Kennedy's, crops out on the Yoonaby, on S. 10, T. 7, R. 5 E. 

 The occurrence of the Rotten Limestone at Guntown Station, M. & C. R. R. 

 has been mentioned. 



121. It would be tedious to enumerate the numerous localities at which the 

 rock crops out on the territory laid down on the map, since each one is little 

 more than a repetition of the other. N. of Old Town Creek, Pontotoc countv 

 prairie occurs only locally, in limited patches ; S. of the stream mentioned we 

 find the "Chickasaw Old Fields," called so probably from their resembling a 

 clearing ; they are nothing more than small prairies, in which the Rotten Lime- 

 stone lies very near the surface, so as to te at times touched by the plow while 

 the rain-water also cuts its channels into it. Their soil is black, or whitish 

 waere the rock itself forms a large quotum of it, and very fertile ; but that 

 which results from its intermixture with the yellow soil of the adjoining, gently 

 undulating uplands — "mahogany soil" — is preferred as being safer. Still further 

 S , on the Coonewar, Chiwapa and Tallabinela, the regular prairies set in with 

 their 6 to 10 foot stratum of yellow clay overlying the Rotten Limestone; while 

 the beds of the creeks usually cut into the latter. In Pontotoc count}' the 

 western line of the Rotten Limestone region is generally pretty distinctly 

 marked by the steep slopa of the Pontotoc Ridge, on whose summit the strata 

 of the Ripley group appear. Thus, on the road from Tardyville to Ellistown 

 a mile W. of the latter place ; on the Re Hand and Camargo road, immediately 

 W. of the crossing of the E. fork of Tallabinela Creek ; on the Okalona and 

 Coffeeville road, at the crossing ot" Chuckatonche Creek. W. of the points men- 

 tioned, the country becomes hilly, dark tinted Orange Sand sets in, and bald 

 hilltops on which the material is sandy, with fossils of the Ripley group, are 

 seen. 



122. The Pontotoc Ridge terminates, or at least, loses its peculiar character 

 between the Houlka and Chuckatonche, N. E. of Houston. At Houston and 

 E. and S. E. of the same, the cretaceous material struck in the wells is litholo- 

 gieally intermediate between the micaceous Owl Creek (Ripley Group) marl and 

 the Rotten Limestone, and its fossils likewise indicate an intermediate position • 

 for while the leading shells of both groups appear to be wanting, it does contain 

 some of the fossils of each. At Houston, immediately on the edge of the Flat- 

 wood-?, this stratum (as ascertained in wells) is about 100 feet in thickness 

 being unlerlaid by water-bearing sand. At Sparta, S. E. of Houston, the same 

 stratum is struck in shallow wells, and cisterns, but in deep wells no water is 

 found at any depth less thim 300, and S. of Sparta, 1000 feet is no uncommon 

 depth. Sparta is probably on the eastern edge of the transition stratum in 

 question, for eastward of the place (around which, as at Houston, the country 



