用黄土地球化学参数进行古气候定量估算的初步尝试

A preliminary study on quantitative estimate of Palaeoclimate by using geochemical transfer function in the Loess Plateau

尝试了用表土地球化学转换函数恢复渭南剖面最近１３ 万ａ 来的古温度、古降水。结果显示：（１）全新世适宜期及末次间冰期时，降水量显著增加，渭南地区的年降水量可大于７００ ｍ ｍ ；（２）末次冰期时降水量明显低于全新世适宜期及末次间冰期，但是这一时期有一些次一级的变化，特别是与深海Ｏ 同位素阶段４ 对应的时期，不仅降水量显著降低，而且还有更次一级的变化；（３） 全新世适宜期时，渭南地区的年平均温度在１２～１４ ℃左右，末次冰期时年平均温度在８．５～１１．５ ℃左右，而末次间冰期的古温度在１２～１５ ℃之间。

A 130 000 year quantitative palaeoclimate reconstruction at Weinan profile was conducted by using geochemical transfer function. The results show that Holocene optimum and the last interglacial stages were characterized by an increasing in precipitation. In Weinan the annual mean precipitation could be more than 700 mm. Precipitation during the last glacial period was less than that of the Holocene optimum and the last interglacial stages, and it had some within stage oscillations, even more second order oscillations occurred in Stage 4. During Holocene optium, the temperature in Weinan was about 12～14 ℃, whereas about 8.5～11.5 ℃and 12～15 ℃during the last glacial time and the last interglacial period, respectively.