120'lj 202 - LOCALITIES OF JACKSON OROUP. 129 



.:: at a moderate depth (20 to 30 feet) the ligmta-gypseous material is 

 struck, yielding' undrinkable water. The same strata are seen all the way 

 between Canton and Jackson, and crop out very characteristically half a mile 

 N. of the State House. Yet we find lignilic strata cropping out on Moody's 

 branch, a mile N. E. of the State House, and that at a hypsometrical level 

 obviously higher, than that at which, a mile below, we find the beds of blue 

 fossiliferous sand cropping out on Pearl River and in the bed of Dry Creek. 

 Makiug due allowance for the undulations of the surface at both stations (Canton 

 and Jackson), the surface of the lignitic strata, so far from exhibiting a southward 

 dip, is still slightly higher at Jackson than at Canton. It seems difficult to 

 account for this condition of things unless by supposing a local upheaval of the 

 underlying formation to have taken place before the deposition of the lowest of 

 the Jackson stage. 1 am not aware whether or not similar irregularities exist 

 in other meridians ; it is certainly not the case on that of the Chickasawhay 

 River, where the same strata sink regularly below the water level, as we advance 

 southward. 



201. Localities of tfa Jackson Group. — lam not personally acquainted with 

 the extreme western portion of the formation, in Yazoo and S. W. Madison. 

 According to L. Harper, the marine eocene strata first appear a short distance 

 S. of Satartia, Yazoo county, where the material is of a clayey character, and 

 contains, among other fossils mentioned by him, Venericardia planicosfa and 

 Gastridium vetustum ("JEbuma") — sufficient to distinguish it from the Vicksburg 

 marls, further S. I have also been informed, that bones of the Zeuglodon have been 

 repeatedly found in the neighborhood of Satartia ; and vertebra? of the same have 

 been kindly forwarded to the collection of the Geological Survey, by W. S-. 

 McKee, Esq., residing near Satartia, Yazoo county. Harper further mentions 

 the occurrence of compact limestone containing Venericardiapla'dicosta, on the 

 bluff near the Warren county line, and of a bed of marl (fossils not mentioned) 

 on S. 1, T. 18, R. 5 E., Warren (Yazoo ?) county ; I have seen no specimens of 

 these materials. 



202. About 3 miles N. of Canton, the most northerly indications of a calca- 

 reous formation are met with, in the shape of soft white concretions of carbonate 

 of lime, appearing in a rather stiff yellow loam, at the bottom of gullies. These 

 indications increasa as we advance southward, and in some small R. R. cuts N. 

 of Canton, we find profiles in which the common yellow surface loam is under 

 laid, at the depth of about 3 feet, by a heavier loam containing calcareous 

 concretions, of about the same thickness. This in its turn, is underlaid by a 

 stiff, bluish white clay of massy cleavage ("joint clay"), with white, calcareous 

 concretions and veins, but containing no fossils. There are not, between these 

 several materials, distinct stratification lines ; there is rather a gradual transition 

 from one to the other, the upper being probably derived, in the main, from the 

 blue clay below, but changed by oxidation, the admixture of sand and the 

 partial removal by lixiviation of the lime, which has accumulated in the lower 

 portion of the mass. 



203. The country between Canton and Calhoun Station, on the N. 0., J„ & 

 G. N. R. R., is so level as to afford little opportunity of examining the formation. 

 The peculiar greenish hue, however, which the yellow surface loam assumes hi 

 the deeper washes, sufficiently indicates the proximity to the surface, of the 

 calcareous clays, which are also struck in cisterns — shallow wells yielding either 

 undrinkable water or none at all. S. of Calhoun Station, the strata of the 

 calcareous tertiary are well exposed ; affording the following section in the 

 "Montgomery cut :" 



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