發(fā)布時(shí)間：2019-06-27 07:48

【摘要】：騰格里沙漠南緣土門剖面末次間冰階層段(TMS 3)由風(fēng)成砂、黃土狀亞砂土、砂黃土、古土壤、湖相沉積物和沖積黃土等6種沉積相相互疊覆構(gòu)成。粒度分析結(jié)果顯示,該層段以砂質(zhì)沉積物為主,粉砂次之,黏土最少,平均值分別為65.45%、26.72%和8.83%;在砂粒級(jí)中,以細(xì)砂含量最高,其次為極細(xì)砂,其余為中砂-粗砂顆粒。粉砂含量、黏土含量、Mz和σ在風(fēng)成砂中呈現(xiàn)谷值,在其他沉積相為峰值,中砂-粗砂和細(xì)砂則相反。粒度指標(biāo)指示騰格里沙漠南緣土門剖面末次間冰階至少經(jīng)歷了13次暖濕和12次冷干的氣候波動(dòng),且可劃分為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個(gè)亞段,25次冷暖波動(dòng)與格陵蘭冰芯和中國南方石筍記錄的D/O事件以及北大西洋深海沉積物記錄的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，

本文編號(hào)：2506620