Annual rings of algaroba ( <i>Neltuma pallida)</i> tree from northern Peru

This study examines Neltuma pallida wood from the Cerro Laguna archaeological site in coastal Peru to establish a floating chronology and absolute dating. Ten cross-sections yielded a 70-year chronology (CLAA1). Alpha-cellulose was extracted from five single growth rings from one sample for radiocarbon dating, then wiggle-matching in OxCal v4.4 using SHCal20. Results place the youngest ring at 1314–1330 CE (95.4% probability), situating the full sequence in the period between 1253 and 1322 (±8) CE. Statistical analyses show a robust dendrochronological signal, and ring-width data suggest strong El Niño Southern Oscillation (ENSO) events around 1300 CE. These findings confirm Cerro Laguna's Late Intermediate Period occupation and allow us to assume that the entire 70-year period can be used to improve the calibration curve for the Southern Hemisphere.