最近13万年以来洛川黄土剖面中P_(org)/P_(inorg)分布及其古气候指示意义

P_(org)/P_(inorg) fluctuation in the Luochuan loess section during the last 130 ka and its paleoclimatic significance

对末次间冰期以来洛川黄土进行了有机磷/无机磷(Porg/Pinorg)比值测量。结果表明,黄土中Porg/Pinorg比值的分布主要受降水量和温度的影响,是有机磷和无机磷在不同时期随气候变化相互转化的结果。此指标的变化与黄土-古土壤的变化大致相关,与洛川黄土磁化率曲线相一致,与深海氧同位素可进行很好的对比。此比值与夏季风强弱程度乃至与全球气候变化有密切的联系。Porg/Pinorg比值可作为一种反映古气候环境变迁的新指标。

Porg/Pinorg ratio in the Luochuan loess section during the last 130 ka is measured, which is affected by temperature and precipitation, resulting from conversion of both Porg and Pinorg each other with variation of paleoclimate during different geological periods. Porg/Pinorg ratio variation correlates with loess paleosol sequence. Porg/Pinorg ratio is consistent with magnetic susceptibility in the Luochuan loess section. Variation of Porg/Pinorg ratio has an obviously close relation with intensity of summer monsoon, and can match well the marine oxygen isotope records. Therefore, a new proxy recording paleoclimatic variation, P_(org)/P_(inorg) ratio, is established.