A 14,000-year oxygen isotope record from diatom silica in two alpine lakeson Mt. Kenya

Oxygen isotopes are sensitive tracers of climate change in tropical regions . Abrupt shifts of up to 18 per mil in the oxygen isotope ratio of diatom s ilica have been found in a 14,000-year record from two alpine Lakes on Mt. Kenya. Interpretation of tropical-montane isotope records is controversial, especially concerning the relative roles of precipitation and temperature. Here, we argue that Holocene variations in delta O-18 are better explained by Lake moisture balance than by temperature-induced fractionation. Episod es of heavy convective precipitation dated similar to 11,100 to 8600, 6700 to 5600, 2900 to 1900, and <1300 years before the present were linked to en hanced soil erosion, neoglacial ice advances, and forest expansion on Mt. K enya.