LOESS-DEPOSITING WINDS IN LOUISIANA 
F. V. EMERSON 
Louisiana State University 
The data on which this paper is based were accumulated from 
field work on the two loess belts of Louisiana together with a few 
examinations of loess at Vicksburg and Natchez, Mississippi. 
Practically all the evidence points to an eolian origin for the south- 
ern loess. Assuming this origin, it appears from two lines of evi- 
dence, namely the amounts and thickness and the chemical 
composition of this loess, that the principal depositing winds were 
westerly and southerly. 
THE LOESS 
The loess in Louisiana is of brownish to gray-brown colors and 
shows the usual vertical cleavage. For the most part it overlies 
Lafayette and Columbia sandy and gravelly materials and Pleisto- 
cene clays which are usually correlated as Port Hudson. It was 
deposited on an eroded surface, hilly in most places where the loess 
overlies the Lafayette and Columbia formations, and rolling to 
undulating where it overlies the clays (Fig. 1). There are two 
loess belts fringing the Mississippi lowlands, extending nearly to 
the Gulf. The eastern belt, beginning about 15 miles south of 
Baton Rouge, about 80 miles from the Gulf, with a width of about 
15 miles, widens to the northward to a width of perhaps 4o 
miles in Mississippi. This belt continues northward through 
Tennessee to the Ohio River with practically no interruptions 
except at stream valleys. The western belt begins near Lafayette 
about 40 miles from the Gulf and extends to the Red River valley, 
a distance of about 50 miles, with an average width of 8 to 10 miles. 
Ten miles to the north the loess again appears in an island-like area, 
the Avoyelles Prairie, of about 80 square miles. About 40 miles 
northeast the loess belt again reappears at Sicily Island, from which 
it extends northward into Arkansas in a belt known locally as the 
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