T107] 



EUTAW GROUP 



m 



(Sec. 4.) 



SECTION AT LISBY'S, SHOWING THE RELATIVE POSITION OF THE 



ROTTEN LIMESTONE AND EUTAW GROUP. 



CHARACTER OF STRATA. 



ti 



Rotten Limestone hilltops, with Exogyra costata, Janira 

 101 5-costata, Radiol'Ly, etc. The lower ledges sandy and 

 micaceou;. 



Coulter's Ferry sands, non-effervescent. In the lower 



portion of the bed, large round concretions (3 to 4 feet in 



diameter) of calcareous, non-fossiliferous sandstone, 

 usually very hard, sometimes soft. 



3 Dark colored, bluish, laminated clay. 



The laminated clay appears at the same level at which, a short distance off, " 

 we see only sands ; showing that on the large scale as well as on the small, ' 

 these deposits may be incontinuous, lenticular masses. t 



These outcrops are precisely analogous to those described by Tuomey (First : 

 Report, p. 118 ff.) as occurring at Finchs' Ferry, near Eutaw ; save in this, ,' 

 that here as elsewhere in Mississippi, these sands are non-fossiliferous. r 



A mile above Cotton Gin Port, at the ford, we find the Coulter's Ferry sands » 

 outcropping in the bed of the river. At the place itself, on the river bank, the * 

 laminated clay crops out two feet thick, overlaid by yellowish sand. 



107. Thence down to Aberdeen, and so far as I know, from Aberdeen to 

 Barton, on the Tombigbee, the Tombigbee Sand Group occupies the river bluffs, 

 The sands and clays of the Eutaw Group are, however, struck in the bora! 

 wells at Aberdeen, and (at depths corresponding pretty accurately to a dip of 

 25 feet W. per mile) in those at Pikeville and Buena Vista, Chickasaw county, 

 In some of the Aberdeen wells, a bed of white pebbles 8 feet in thickness has 

 been found overlying a black, fetid, lignitic ma^s, at the depth of 217 to 220 

 feet; pebbles are mentioned by Tuomey as forming part of these strata in 

 Alabama, also. The lenticular or wedge-shaped laminae of the clay are some- 

 times exceedingly troublesome in boring, as their smoothness imparts to them 

 an uncontrollable tendency to slip sideways. 



At Barton bluff, we find the following section : 



