陕北黄土区全新世气候替代指标意义及其关系

古气候替代指标在某种程度上包含了温度、降水、季风等气候信息,但每种指标对不同气候信息的表达程度并不相同,并且各种气候替代指标之间的关系以及它们的环境指示意义仍存在一些不确定性。通过对陕北黄土地区全新世土壤剖面进行研究,分析全新世气候替代指标演化规律,运用R/S分析法探讨各气候替代指标之间的关系及其意义。结果表明,磁化率(χIf)可以反映暖湿或冷干气候;碳酸钙含量(CaCO3)则主要受到降雨的影响;总有机碳含量(TOC)与温度变化密切相关;全铁含量(TFe)和酸碱度(pH)同时受到温度和降雨量的影响;0.01~0.05 mm粗粉粒含量和<0.005 mm的黏粒可以作为冬季风的替代指标。

THE SIGNIFICANCE AND RELATIONSHIP OF MAIN CLIMATIC INDICATORS FOR THE HOLOCENE IN NORTHERN SHAANXI

The paleoclimatic indicators certainly contain some climate information, such as temperature, precipitation, monsoon, and so on. However, each indicator expresses the climate information to different degrees. The environmental significance and relationship of climatic indicators need further investigation. In this regard, three Holocene soil profiles in Northern Shaanxi are studied for the change in paleoclimatic indicators. The R/S analysis method was used in this study for the purpose. The results indicate that the magnetic susceptibility of soil (χIf), total content of furrum (TFe), and pH can reflect the change in both temperature and rainfall during the soil formation, whereas the content of calcium carbonate (CaCO3) and the total organic carbon (TOC) are mainly influenced by rainfall and temperature, respectively. The particle size composition (clay fraction <0.005 mm and coarse silt 0.01~0.05 mm) can be used to describe the change of East Asian winter monsoon. This study has provided a theoretical basis and scientific reference for the research on Holocene evolution of paleoclimate.