"Influences of temperature and the meteoric water δ18O value on a stalagmite record in the last deglacial to middle Holocene period from southwestern Japan". (1st February 2021)

• Record Type: Journal Article
• Authors: Kato, Hirokazu; Amekawa, Shota; Hori, Masako; Shen, Chaun-Chou; Kuwahara, Yoshihiro; Senda, Ryoko; Kano, Akihiro
• Is Part Of: Quaternary science reviews. Volume 253(2021)
• Publication Date: 2021-02-01
• Subjects: Stalagmite -- Speleothem -- Oxygen isotope -- Carbonate clumped isotope -- Paleoclimate -- Temperature change -- Meteoric water oxygen isotope -- Deglacial period -- Holocene -- Southwestern Japan; Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2020.106746
• Languages: English
• ISSNs: 0277-3791

Abstract

Abstract: Our understanding of stalagmite δ 18 O paleoclimate records would be significantly improved by determining the relative influence of the two factors, temperature and water δ 18 O. Here we apply carbonate clumped isotope thermometry to a well-dated (18.1–4.5 ka) stalagmite, Hiro-1 from Maboroshi Cave in Hiroshima Prefecture, southwestern Japan. The Δ47 values from 50 stalagmite layers, calibrated using Δ47 -temperature relationships observed in modern stream tufa from Japan (Kato et al., 2019) yield estimates of paleo-temperature and water δ 18 O variability. Several layers affected by significant prior calcite precipitation under a dry climate display strong kinetic isotope influences: positive δ 18 O and negative Δ47 deviations. Except for these layers, Hiro-1 Δ47 records temperature changes that are broadly consistent with climatic stages after the last glacial maximum (LGM) to the mid-Holocene, although the significant Bølling-Allerød warming does not appear in Δ47 values. The estimated temperature difference between the period after the LGM (18.0–16.0 ka) and mid-Holocene (7.7–4.9 ka) was 8.3 °C. Using Δ47 -temperature, stalagmite δ 18 O values, and change in seawater δ 18 OSW, the comprehensive isotopic depletion from vapor source (seawater) to meteoric water was reconstructed. We obtained larger 18 O-depletion (−9.5 to −10.0‰) in the pre-Holocene section than in the middle Holocene section (around −8.5‰). The larger 18 O-depletion of the pre-Holocene period was ascribed to a larger fractionation during vapor generation under a lower temperature, change in seasonality of precipitation, or a longer vapor trajectory due to the subaerially exposed Seto Inland Sea. Unlike Chinese stalagmites, δ 18 O record of Hiro-1 stalagmite appear largely unaffected by rainfall amount. Highlights: Carbonate clumped isotope measurements for 50 layers of a Japanese stalagmite. Terrestrial temperature record from 18.0 to 4.5 ka in southwestern Japan. Meteoric δ 18 O reconstruction by subtraction of temperature effect on stalagmite.