14 C4EOLOGY AND MINERAL RESOURCES OF MISSISSIPPI. 
The characteristic material of the Eutaw consists of fine-grained micaceous sands, calca- 
reous in the upper part, with more or less glauconite or greensand. Irregular beds of sandy 
clays are not infrequent. The lowest division is largely composed of highly cross-bedded 
sands of various colors, such as orange, red, blue, and deep yellow. This lower part is dis- 
tinguished with difficulty from the upper Tuscaloosa, and the line between the two forma- 
tions is therefore arbitrarily drawn. 
The irregularity in the deposition of the lower Eutaw is well marked along upper Tombig- 
bee River and its tributaries and also along the streams in Alabama. No one stratum of 
sand or clay can be traced continuously for any great distance. A bed of clay 8 or 10 feet 
thick may thin out in as many rods and entirely disappear. 
A well at Eutaw, Ala., reached the clays of the Tuscaloosa formation at a depth of 400 
feet. The wells at Columbus, Miss., obtain water below the first clay of the Tuscaloosa at 
a depth of about 300 feet. Columbus is located on the western edge of the Eutaw formation 
and the wells therefore pass through its entire thickness, which here is less than 300 feet. At 
the northern border of the State the formation is much thinner. The combined thickness 
of the Eutaw and the underlying Tuscaloosa at Corinth, Miss., is less than 375 feet, while in 
western Alabama it is 9(K) to 1 ,000 feet. At Corinth the top of the Eutaw was reached at a 
depth of about 90 feet and the hard Paleozoic rocks at 450 feet. If the two formations thin 
proportionally the Eutaw here would be about 90 feet and the Tuscaloosa 270 feet thick. 
A record of the well was kept, but the driller failed to notice any change in passing from the 
Eutaw to the Tuscaloosa. 
The area occupied by the Eutaw consists of a narrow band of territory 5 to 12 miles wide, 
lying just east of Tombigbee River in Monroe and Lowndes counties, and on the west side of 
the river north of this, extending through eastern Lee, east-central Prentiss, and eastern 
Alcorn counties. 
The change from the sandy Eutaw formation to the overlying Selma chalk is not an abrupt" 
stratigraphic break. On the contrary. there is a gradual change from the upper members of 
the Eutaw to the lower division of the Selma. It is so gradual that experienced well drillers 
often fail to distinguish the line of contact between the two formations. The upper Eutaw 
contains a large amount of carbonate of lime, greensand, and a fauna greatly resembling that 
of the Selma chalk. 
The section given below offers an excellent opportunity for studying the transition beds 
between the Selma and Eutaw. At a distance of 4 miles above Columbus, on Tombigbee 
River, the bluff on the west side reaches about the same height as the hill on which Columbus 
is built . For a distance of 1 mile along the river the cliff exposes a fine section of the upper 
Eutaw and the basal beds of the Selma. West of the river the Selma prairies slope gently to 
the top of the bind' and then suddenly descend 40 to 50 feet to the water's edge. The east 
side of the river is a level bottom but little above the river. At the town of Columbus there 
are high bluffs on the east side and a wide bottom on the west side of the river. The same 
black prairie soils of the Selma, which come within 3 miles of the river due west of Columbus, 
extend to the high bluff along the river 4 miles above town. The following section was 
obtained in the bluff where the dirt road comes down to the river: 
Section on Tombigbee River Jf miles north of Columbus. 
11. Lafayette. 
10. White to gray joint clay of the Selma, containing less sand at the top than at the hottom. 
In the unweathered condition the clay is of a pale-blue color, containing green and black Ft. In. 
sand 8 
9. Greensand, unconsolidated, highly calcareous, and containing numerous large oyster shells. 5 
8. Ledge of indurated greensand, calcareous, with large oyster shells. This ledge, being harder 
than the stratum above, stands out more distinctly and from a distance looks very much 
like a hard, compact ledge of limestone 12 
7. Lighter colored unconsolidated sand containing a few very small fossils and no large ones... 1 2 
6. Greensand, nonfossiliferous 6 
5. Slightly fossiliferous, gray micaceous sand 5 
4. Ledge of indurated sand, slightly fossiliferous 10 
3. Greensand, unconsolidated 4 
2. Ledge of indurated sand 8 
1. Fossiliferous greensand to water' s edge 4 
