Throughout the excavation of Mound C, major profiles, horizontal plans at ½-foot intervals, and occupational features were described in the field notes and drawn to scale. Major profiles and features were photographed. Most of the digging was done with shovels, but trowels were used in part for excavating the two thin floor zones and for several other situations where close attention to detail was desirable. Because of time limitations only representative, spot screening was attempted. STRUCTURE OF MOUND C 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):