黄土古土壤发育指数的环境图谱研究

The Environmental Tupu of Soil Growth Index

在确认"黄土也是古土壤"的前提下,对新近发现的位于黄土高原西北部的宁夏彭阳剖面进行了磁化率、粒度、色度、CaCO3等环境变化代用指标的系统测试。通过设立土壤发育指数,构建了800kaBP沙漠黄土生态脆弱区的高分辨率环境图谱。此图谱由8次较大规模的寒漠扩张,1～3次亚热带北迁所组成。这对丰富黄土古环境变化信息,加强区域对比研究具有重要意义。

Based on the Pengyang profile and environmental change indexes,the Environmental Tupu ofsand-loess region for 800kaBP has been designed,which revealed that the sand approaching taked place in the 800～750 ka,760～740 ka,720～710 ka,650～630 ka,550～480 ka,340～330 ka,220～200 ka and 80～70 kaBP, the Subtropics moving northward occurred about 700～660 ka, 430～410ka,120～90 kaBP.