44 The American Geologist. j-uv. i89i 
THE FLOOD-PLAIN AND THE MOUND BUILDERS. 
By Stephen D. Peet, Ph. D., Mendon, 111. 
Oue of the most interesting problems whicli the geologist and 
the archaeologist in their combined capacity maj- undertake to 
solve is that presented by the flood-plain. The flood-plain is, to 
l)e sure, altogether a natural creation while the mound-l)uilders' 
works are artificial. Yet the two are so related that the^- maj' 
well be studied together. Both are comparatively modern, the ap- 
pearance of the flood-plain and the erection of the earth-works 
having been subsequent to the glacial epoch, but both preceded 
the historic period. Great changes have indeed occurred in them 
since the historic times, but they are in opposite directions, as the 
flood-plain seems to be more plainly- visible and is fast becoming 
a regular formation, the last of the sedimentary laj-ers, while the 
earth-works are fast disappearing and are only advancing in their 
decay and (Jesolation. 
The enquir}' which we desire to make has regard to the time 
which has probabh' elapsed since the erection of the earth-works 
as indicated by the growth of the flood-plain. 
The first enquir}' will be about the so-called elephant eflSgy 
which we referred to in one of our former papers. This effigj' is 
on the flood-plain, one of the ver}' few which have been discov- 
ered on this plain. The question which we ask is, was jt an ele- 
phant which was thus built in effigy on a plain which is now oc- 
casionally covered with water s as to be cotemporaneous with 
the ancestors of the Hunter Indians ? The eflflg}' of the elephant 
seems to have met the same fate in Wisconsin which the rotunda 
mound has in Ohio. The flood has come up occasionally- and 
washed his feet and his proboscis until his- form is obscured be- 
yond recognition. The clover was to be seen growing on the 
form when we last saw it, the water of recent freshets having 
drowned out all the clover vegetation in the swale where he lay, 
but for the life of us we could not tell whether the effigy was of an 
elephant, a bear or some other huge animal . , , . We, however, con- 
cluded that the effig}- must have been comparativeh' recent for the 
flood-plain must have been constauth* covered with water not a 
very long time ago ; that is, as we reckon time in the histor}' of 
extinct animals. Our opinion is that the Cherokees built their 
Iturial-mounds on the flood-plain of the Scioto in Ohio about the 
same time that the Winnebagoes built a bear or buffalo effig3- on 
