Holocene lake-level fluctuations of Lake Aricota, Southern Peru

Lacustrine deposits exposed around Lake Aricota, Peru (17° 22′S), a 7.5-km² lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal ¹⁴C reservoir effects (<350 yr). Diatomites associated with highstands several meters above the modern lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 ¹⁴C yr B.P. and ended ∼ 2700 ¹⁴C yr B.P. Moderately high lake levels occured at 1700 and 1300 ¹⁴C yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16°S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes.