Paleotemperature changes over the past 3000 years in eastern Beijing, China: A reconstraction based on Mg/Sr records in a stalagmite
Paleotemperature changes over the past 3000 years in eastern Beijing,China:A reconstraction based on Mg/Sr records in a stalagmite

The Mg/Sr ratio in a stalagmite, which is directly proportional toD Mg/ca, the solid-liquid distribution coefficient of Mg, is proposed as a geochemical thermometer to estimate paleotemperature changes. The paleotemperature change in eastern Beijing over the past 3000 years has been reconstructed by using this thermometer in the stalagmite ZFFS-1 from Jingdong Cave. The records can be divided into two periods: 3000–2000 aBP, cool and wet, the air temperature averaging 9.8°C; and 2000 aBP-present, hot and dry, the air temperature being 1°C higher than the mean value (11.7°C) of the past 3000 years. During 500–200 aBP, the air temperature was about 1.2°C lower than that of the present, corresponding to the Little Ice Age in Europe. Like δ18O and δ13C, Mg/Sr (orD Mg/Ca) reflects an obviously warming trend of the past 200 years. These results are supported by historic records.