The profiles revealed that the bulk of the mound fill comprised a single
structural member composed of dark gray, humus stained, sandy, midden
soil (Fig. 3). It reached a maximum height of 1.4 feet above the surface
of the surrounding floodplain and extended down to an average depth of
1.4 feet below the floodplain surface. The fill of Mound A contained
many tiny fragments of mussel shell, bone, charcoal, and stone chips, as
well as a few potsherds, projectile points, and other artifacts. Some of
the shell and bone fragments showed evidence of burning. The mound fill
was unquestionably derived from an occupational area containing an
appreciable quantity of cultural detritus.
The top of soil Zone IIb in the area surrounding the mound was, on an
average, about 0.7 feet below the surface of the floodplain. The bottom
of the mound structure, however, extended to an average depth of 1.4
feet below the floodplain surface where it terminated within Zone IIb
(Fig. 3). Thus the surface of Zone IIb immediately beneath the mound
formed a shallow, saucer-shaped depression which must have resulted from
digging away of the topsoil before the mound was erected. This shallow
pit (perhaps originally 1.0 to 1.5 feet deep) was approximately the same
size and shape as the base of the mound.