This site is an early sedentary village located on the south-facing slope of the Tlapacoya volcano between Lakes Xochimilco and Chalco in the southern part of the Basin of Mexico. Christine Niederberger's excavations at the site in the 1970s showed a long occupation spanning the last 6000 years. Teosinte (Zea mays sp. mexicana) was used at the site as evidenced by both seeds and pollen. This early Zea use occurs with the first human occupation of the site during the La Playa phase, and is associated with cultural deposits overlying a Lake Chalco beach remnant, with a radiocarbon date from Layer 25 of 7040±115 B.P. (I-4405). The succeeding Zohapilco phase deposits with an associated 14C date of 4250±110 B.P. (Layer 17) (I-4404) has Zea pollen that is slightly larger and three times more frequent than Zea pollen in the La Playa deposits. This may be maize rather than teosinte (Niederberger 1979:137).
| ID | Other ID | Type | Subtype | Uncal BP (years) | ± 1 σ (years) | Median cal BP (years) | Lower cal BP (years) | Upper cal BP (years) | δ13C | Contaminated? |
|---|---|---|---|---|---|---|---|---|---|---|
| 309 | I-4404 | MicroSample | pollen | 4250 | 110 | 4795 | 5271 | 4445 | No |