PEDOGENESIS OF COTIGA MOUND, A 2100-YEAR-OLD WOODLAND MOUND IN SOUTHWEST WEST-VIRGINIA

Cotiga Mound, an Early Woodland mortuary mound constructed 2100 YBP, w as sampled to evaluate diagnostic horizon development during a well-de fined, relatively short period of time. Five columns (profiles), three of which extended into the submound terrace soil, and one Giddings co re of the terrace soil were sampled for particle-size, pH, organic C, and micromorphology analysis. Six additional cores were collected to c haracterize the terrace soil. The mound was constructed of acid, silty material, in a manner that resulted in basket-loading macrofabric con sisting of long, sinuous, thin layers contrasting in color and texture . Pedogenesis destroyed the macrofabric and formed a solum in the uppe r 0.75 to 1.0 m of the mound. The solum consisted of a thin, dark A ho rizon; an intermittent, thin E horizon; and a variable B horizon. The B horizon was thickest at the mound crest, contained clay films on ped surfaces, and was designated Bt. On side slopes, the B horizon was th inner, lacked clay films, and was designated Bw, No B horizon was form ed at the mound periphery. Clay distribution indices indicated that th e Bt horizon was borderline cambic-argillic, consistent with those typ ical of 2000-yr-old mid-Atlantic alluvial soils. Clay films were spars ely distributed throughout the mound, indicating that clay accumulatio n mechanisms were largely inefficient in the 2100 yr. Mound soils were classified as Typic Dystrochrepts grading to Typic Hapludults at the mound crest. These soils are similar to floodplain soils mapped nearby . Submound terrace soils and adjacent terrace soils were classified as Humic Hapludults.