腾格里沙漠南缘土门剖面末次间冰阶层段的粒度特征及其反映的气候-沉积环境
发布时间：2019-06-27 07:48
【摘要】：腾格里沙漠南缘土门剖面末次间冰阶层段(TMS 3)由风成砂、黄土状亚砂土、砂黄土、古土壤、湖相沉积物和冲积黄土等6种沉积相相互叠覆构成。粒度分析结果显示,该层段以砂质沉积物为主,粉砂次之,黏土最少,平均值分别为65.45%、26.72%和8.83%;在砂粒级中,以细砂含量最高,其次为极细砂,其余为中砂-粗砂颗粒。粉砂含量、黏土含量、Mz和σ在风成砂中呈现谷值,在其他沉积相为峰值,中砂-粗砂和细砂则相反。粒度指标指示腾格里沙漠南缘土门剖面末次间冰阶至少经历了13次暖湿和12次冷干的气候波动,且可划分为TMS 3e(54 200~59 750aBP)、TMS 3d(54 200~40 800aBP)、TMS 3c(40 800~32 800aBP)、TMS 3b(32 800~25 400aBP)和TMS 3a(25 400~22 940aBP)等5个亚段,25次冷暖波动与格陵兰冰芯和中国南方石笋记录的D/O事件以及北大西洋深海沉积物记录的H事件具有很高的同步性。
[Abstract]:The last ice strata section (TMS 3) in the southern margin of Tengger Desert is composed of six sedimentary phases, namely, aeolian sand, loess subsandy soil, sandy loess, paleosol, lacustrine sediment and alluvial loess, which are composed of aeolian sand, loess subsandy soil, sandy loess, paleosol, lacustrine sediment and alluvial loess. The results of grain size analysis show that the layer is dominated by sandy sediments, followed by silt, and the average value of clay is 65.45%, 26.72% and 8.83%, respectively. in the grain size, the content of fine sand is the highest, followed by very fine sand, and the rest is medium sand and coarse sand. Silt content, clay content, Mz and 蟽 showed valley value in aeolian sand, but peaked in other sedimentary phases, but opposite in medium sand-coarse sand and fine sand. The grain size index indicates that the last interice scale has experienced at least 13 warm and wet and 12 cold and dry climate fluctuations in the Tengger desert southern margin, and can be divided into five subsections: TMS 3e (54200 鈮，
本文编号：2506620
[Abstract]:The last ice strata section (TMS 3) in the southern margin of Tengger Desert is composed of six sedimentary phases, namely, aeolian sand, loess subsandy soil, sandy loess, paleosol, lacustrine sediment and alluvial loess, which are composed of aeolian sand, loess subsandy soil, sandy loess, paleosol, lacustrine sediment and alluvial loess. The results of grain size analysis show that the layer is dominated by sandy sediments, followed by silt, and the average value of clay is 65.45%, 26.72% and 8.83%, respectively. in the grain size, the content of fine sand is the highest, followed by very fine sand, and the rest is medium sand and coarse sand. Silt content, clay content, Mz and 蟽 showed valley value in aeolian sand, but peaked in other sedimentary phases, but opposite in medium sand-coarse sand and fine sand. The grain size index indicates that the last interice scale has experienced at least 13 warm and wet and 12 cold and dry climate fluctuations in the Tengger desert southern margin, and can be divided into five subsections: TMS 3e (54200 鈮，
本文编号：2506620
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