摘要
对陕西丹凤县茶房村黄土剖面的地层学、沉积学特征以及常量元素、磁化率、粒度等进行了研究。结果表明:茶房村剖面具有表土(MS)→全新世黄土(L0)→古土壤(S0)→过渡黄土(Lt)→马兰黄土(L1)的地层序列;化学风化过程中元素Ca、Na、Mg、K和Si表现为迁移特征,Fe则相对富集,呈现Na>Si>Mg>K>Ca>Al>Fe的迁移序列;剖面总体风化程度处于初等向中等过渡的阶段,不同地层的风化强弱顺序为S0>Lt>L1>L0。化学风化强度的变化表明该区自晚更新世以来气候经历了气候干冷→气候回暖→温暖湿润→气候转凉的变化过程。
The Chafangcun profile in Danfeng,Shaanxi,China were surveyed in detail and then sampled systematically.The stratigraphic and sediment logical characteristics,chemical weathering intensity and the profile structure were observed in the field.Magnetic susceptibility,particle-size distribution,geochemical characteristics were analyzed in laboratory.Results are shown as follows:(1)The stratigraphic sequences of Chafangcun profile changed with the stratigraphic series MS-L0-S0-Lt-L1.(2)The major elements such as Ca,Na,Mg,K and Si were migrated and leached,while the element Fe was slightly enriched during the chemical weathering process.According to the migration ability,the major elements were ranked in the following order:Na>Si>Mg>K>Ca>Al>Fe.(3)The Chafangcun loess have finished the primary chemical weathering process and almost reached the secondary process as a whole.The aeolian sediments went through different degree of pedogenic modification in different periods with the sequence S0>Lt>L1>L0.Geochemical characteristics of major elements indicate that the climate changed as 'cool-dry(before 11500 a BP)→cool-wet(11 500~8 500 a BP)→warm-wet(8 500—3 100 a BP)→cool-dry(since 3100 a BP)'.
出处
《中国沙漠》
CSCD
北大核心
2014年第5期1248-1253,共6页
Journal of Desert Research
基金
国家自然科学基金项目(41271108
41030637
41371029)
中央高校基本科研业务费专项资金项目(GK201301003)资助
关键词
黄土-古土壤
风化程度
古气候
茶房村
loess-paleosol
weathering intensity
paleoclimate
Chafangcun
