Profiles of Mound C revealed remnants of an old stabilized surface with
a well developed soil profile (including a superficial humic zone) lying
immediately beneath the mound fill (Fig. 7). The elevation of the old
surface averaged approximately 99.4 feet which is also the average
elevation of the modern floodplain surface around the mound: therefore
it appears certain that the first of the two houses was built directly
on the floodplain surface and that there has been no appreciable change
in the surface elevation of the floodplain since the mound was built.
The first house burned, after which the second house was built over its
remains; then the second house burned and the mound was erected over the
ruins of the houses.
[Illustration: Fig. 7
HARROUN SITE
41 UR 10
PROFILE OF MOUND C
(IDEALIZED SECTION THROUGH CENTER OF MOUND)
pothole
floor of House No. 2
floor of House No. 1
sterile zone between house floors
post mold
humus (note buried humus zone between N130 and N140)
gray, sandy mound fill
whitish, sandy mound fill
undisturbed sub-mound soil
HARROUN SITE
41 UR 10
PROFILE OF MOUND D
(IDEALIZED SECTION THROUGH CENTER OF MOUND)
pothole
floor of House No. 4
dark brown sand
gray-brown sand
post mold
humus
gray, sandy mound fill
whitish, sandy mound fill
undisturbed sub-mound soil]
A low embankment of sand similar to that at Mound B encircled the house
area just outside the peripheral ring of house post molds (Fig. 7).
Apparently this embankment was built while one of the houses was still
standing since its inner edge is almost vertical in places as though it
had been banked against the outside wall of the house. After the later
house burned, the mound was heaped over both this embankment and the
house ruins.
The geologic structure of the floodplain at Mound C was apparently the
same as previously described although none of the excavations were
carried deep enough to expose Zone I, the basal member of reddish clay.
The mound structure rested on the surface of Zone IIc (Fig. 7) and was
composed of four distinct structural units as follows (in order from
bottom to top):
1. _The lower house floor zone_ (House No. 1). This zone was composed
of blackish sand containing a large amount of charcoal and had an
average thickness of about 0.3 feet. It yielded some artifacts. This
lower house floor lay just above the surface of Zone IIc (the
floodplain surface) from which it was separated by a thin
(approximately 0.1-foot thick) lens of compact sandy clay. The thin
clay lens was apparently a subsurface formation resulting from the
deposition of clay by percolating water along the buried surface of
the floodplain.
2. _The upper house floor_ (House No. 2). This zone consisted of a
slightly compacted, brownish sand containing a large amount of
charcoal and a few artifacts. It lay above the floor of House No. 1,
and was separated from it by a layer of clean, sterile, yellowish sand
0.1 to 0.3 feet thick which probably was placed over the burned ruins
of the first house to provide a clean floor for the second one.
3. _The embankment of yellow-brown sand encircling the house area._ As
was previously pointed out, this member had the appearance of having
been banked against the exterior wall of the house while it was still
standing. Perhaps this provided extra protection from the winter
winds, or its primary purpose may have been to serve as a dike to
protect the house when Cypress Creek overflowed its banks. The maximum
height of this zone was 2.0 feet above the surface of Zone IIc, upon
which it rested.
4. _The final addition to the mound._ This was the sand member which
had been mounded over the house ruins. It was virtually sterile of
cultural material.