The Loess of XatcJiec, Miss. — Shiiiick. 281 
fornily the uppermost deposit, forming' the immediate subsoil, 
on the ridge on which Natchez is located. Underlying it in 
most of the exposures is the Yellow or Brown loam, which 
closely resembles loess, but is not fossiliferous and is usually 
of a deeper red color, though sometimes practically indis- 
tinguishable from it. Hilgard"^' described the Yellow or Brown 
loam as overlying the loess. Later ^NlcGeef in giving the ordei 
of the members of the Columbia formation, places the Brown 
or Yellow loam above the loess, but adds : "The order of the 
first two members might be reversed with equal propriety in 
the southern portion of the embayment ; for the loess is but a 
phase of the loam, and is frequenth- underlain a? well as over- 
lain by loamy deposits." Again (p. 393), referring to the 
succession of strata at Natchez, he places the loess at the sur- 
face and the brown loam below it, — which accords with the 
writer's observations in that vicinity. Still later Mabryt. dis- 
cussing the relation of the brown loam to the loess, said: 
"It would appear that, if my observations be accurate, the 
Brown loam and the loess of 'ttes-'-region are not only homo- 
taxial but synchronous asj. well." ' ?' 
Whatsoever may be the exact relation existing between 
these two deposits elsewhere, at Natchez there appears no trace 
of the brown loam above the loess sO' far as the writer was 
a1:)le to determine. 
The thickness of the loess at Natchez has been variously 
reported. Lyell§ gave it as sixty feet, but he probably in- 
cluded the Brown loam ; Hilgard li reported its average thick- 
ness as between twenty-five and thirty-five feet; McGee!! 
states it as ten to fifty feet : while Capt. C. W. Babbit, of 
Natchez, an experienced surveyor and civil engineer who has 
had much to do with excavations, assured the writer that it 
nowhere exceeded twenty-five feet in thickness. The writer's 
own measurements showed a '.naxinumi thickness of about 
thirty feet, though in the exposures numbered 29 and 31 on the 
map, it seemed to be much more, but accurate measurements 
could not be made. It is probable that the front portion of 
*Hilsarcl, E. W., I. c, pp. 194-195. 
fMcGee, W. J., 1. c, p. 392. 
JMabry, T. C, 1. c, p. 29.5. 
§Prin. of Geology, vol. I. p. 4 HO. 
IIP. 313, !. c. 
HP. 397, !. c. 
