Holocene lake-level fluctuations of Lake Aricota, southern Peru

Lacustrine deposits exposed around Lake Aricota, Peru (17 degrees 22 'S), a 7.5-km(2) 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 C-14 reservoir effects (< 350 yr). Diatomites associated with highstands several meters above the modem lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 C-14 yr B.P. and ended similar to 2700 C-14 yr B.P. Moderately high lake levels occurred at 1700 and 1300 C-14 yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16 degreesS), 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. (C) 2001 University of Washington.