Charred maize (likely cobs) mixed with wood charcoal was recovered from a pit in Feature 31, Premound A structure (Story and Valastro 1977: Table 1). This sample's age reported as: 1120±90, but is corrected for fractionation in this database using the formula from Reimer, Brown and Reimer (2004). In this a δ13C value of -18.0 was used, midway between average wood and maize values. We exclude this sample as possibly contaminated since the wood charcoal could be much older than the maize with which it is mixed.