Co-evolutions of terrestrial temperature and seasonal precipitation from the latest Pleistocene to the mid-Holocene in Japan: carbonate clumped isotope record of a stalagmite

Abstract Quantitative paleotemperature reconstruction is a challenging and important issue in terrestrial paleoenvironmental studies, for which carbonate clumped isotope (Δ 47 ) thermometry is a promising approach. Here we analyzed Δ 47 values from 68 layers of OT02 stalagmite from Ohtaki Cave in central Japan, covering two separate time intervals (2.6–8.8 and 34.8–63.5 ka) to reconstruct temperature and meteoric d 18 O records. The average Δ 47 temperature of the Holocene portion of this stalagmite was 16.3℃ ± 5.6℃, 6.6℃ ± 7.2℃ higher than the average of the latest Pleistocene portion, which was 9.7℃ ± 4.6℃. Δ 47 thermometry also revealed that the coldest intervals (5℃–10℃) correspond to the Heinrich cooling events H4–6, and the warmest interval (up to 19.9℃ ± 6.0℃) in middle Holocene (approximately 6–5 ka) accompanied by the Hypsithermal climate optimum. We also reconstructed past meteoric δ 18 O by subtracting the temperature effect from stalagmite δ 18 O. Average meteoric δ 18 O was less negative in the Holocene (8.22‰ ± 0.99‰ VSMOW) than in the latest Pleistocene (8.81‰ ± 0.84‰). Over centennial timescales, meteoric δ 18 O was more negative during colder periods, such as Heinrich cooling events and the cooling event around 7 ka, and less negative in warmer periods, such as Hypsithermal warming. These relations indicated co-evolution of terrestrial paleotemperature and paleoprecipitation. A temperature dependency of 18 O fractionation from water to vapor is a likely reason for the negative correlation between temperature and meteoric δ 18 O. Additionally, it is possible that increasing lower δ 18 O precipitation from East Asian winter monsoon (EAWM) has decreased the averaged meteoric δ 18 O in colder periods. These temperature effects on meteoric δ 18 O occur in opposite directions to fractionation between water and the stalagmite δ 18 O, explaining the small amplitudes of changes observed in the δ 18 O of Japanese stalagmites.