摘要
通过对新疆伊犁可克达拉晚全新世风沙沉积剖面古土壤特性进行研究,结合沉积物磁化率、TOC、黏粒及CaCO3等土壤发生学指标,发现古土壤发育于黄土母质,是荒漠草原植被下形成的具有弱黏化作用和弱钙积作用的淡灰钙土类型。不同时期风沙-古土壤沉积物的形成揭示了新疆伊犁河谷区3.7kaBP以来经历了多次气候干湿波动,共有6层不同发育程度的古土壤形成,后期形成的3层古土壤发育程度较前期的3层古土壤成熟;古土壤反映的古气候大致以2kaBP为时间界限分为前后两个阶段,前期气候相对干旱,后期气候相对湿润;近500年以来,风沙活动增强,气候又有逐渐变干的趋势。
For the purpose to study the characteristics of the Holocene paleo-aeolian sand and paleosol in the Kekdala profile,Yili of Xinjiang,we made a thorough analysis of magnetic susceptibility,TOC,clay fraction,and CaCO3 of the sediments.The results show that the paleosol is resulted from the further weathering of loess deposits,as a kind of light gray desert soil formed under the weak clayization and calcification conditions in a desert-steppe environment.The paleo-aeolian sand and paleosol sequence suggest that the Yili valley of Xinjiang has suffered many times of climate fluctuations since 3.71 kaBP.There are6 layers of paleosol developed in different degrees during this period,with 3layers formed in the early stage which are more developed than the 3layers formed in the late stage.The paleoclimate inferred from paleosol could be divided into two stages taking the 2kaBP as the boundary,and the climate was dry in the early period but wet in the late period.Since 0.5kaBP,however,the climate has become warm-dry and the aeolian sand was strongly activated.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2016年第5期157-164,共8页
Marine Geology & Quaternary Geology
基金
国家自然科学基金项目(41271031
41501001)
中科院青海盐湖所青年基金项目
