长安四府村32～10 ka BP期间沙尘暴活动的记录

Loess Record of Sand-Dust Storm Activity during 32～10 ka BP in Sifu Village, Chang’an, Shaanxi Province

通过对长安区四府村剖面晚更新世后期黄土样品的粒度分析测定,探讨了沙尘暴活动与土壤颗粒组成的关系及32～10kaBP以来的沙尘暴的活动趋势。结果表明,黄土古土壤序列中粗粉砂含量高和粘粒含量低,反映当时沙尘暴活动强烈,反之,沙尘暴活动弱。冰期沙尘暴活动强主要是冰期降水量少造成的,温度低是次要的。古土壤层S10中的粘粒既包含风尘堆积的原始组分,也包含风化成壤过程中对先前发育的黄土L21改造后的次生组分。32～10kaBP以来,沙尘暴活动具有由弱到强的变化趋势,其中23～10kaBP间活动最强。

According to the grain-size analysis of Loess sample developed in late Pleistocene, we discuss the relationship between the activity of sand-dust storm and grain-size of Loess profile, and know the trend of sand-dust storm activity from 32 ka BP to 10 ka BP. As the result, the content of thick grain reflected the strong period of sand-dust storm activity; on the country, the content of thin grain reflected the sand-dust storm was weak. The sand-dust storm activity was strong during ice age mainly because of the less precipitation but not the low temperature. The form of palaeosol S1 0 is caused by later change of Loess L2 1. The sand-dust storm activity had changing trend from weak to strong from 32 ka BP to 10 ka BP.