青海省五道梁地层剖面晚第三系沉积物与古土壤辨析  

Differentiation of Paleosols from Sediments in Late Tertiary Period of Wudaoliang Stratigraphic Section in Qinghai Province

作　　者：黄成敏[1] 王成善[2] 李亚林[2] 伊海生[2] 

机构地区：[1]四川大学建筑与环境学院,四川成都610065 [2]成都理工大学沉积地质研究所,四川成都610059

出　　处：《山地学报》2003年第4期428-434,共7页Mountain Research

基　　金：国家重点基础发展规划项目(G1998040800)~~

摘　　要：辨别沉积地层剖面中的古土壤层(原位沉积)具有重要的地学意义。论文拟以青海省五道梁地层剖面为例,尝试从剖面样品外部形态特征与内部性质探讨晚第三纪或更早之前沉积物与古土壤辨析方法。形态特征包括沉积物的色调、层次结构、生物扰动作用、植物根系等分析基本排除了研究地层剖面中的层段为古土壤。沉积物中较高的CaCO3含量、较低的铁游离度,均<20%,反映出沉积物源的风化程度低,都说明沉积物形成时的气候条件湿热程度不高。样品稀土元素和微量元素等地球化学特征显示,地层剖面沉积物是经过异地搬运、沉积形成的。It is significant for studies of geosciences to identify territorial paleosols (autochthonous deposits) Selected stratigraphic section of Wudaoliang in Qinghai Province was analyzed morphologically and with inner properties to discuss the methodology on differentiating paleosols from sediments (allochthonous deposits), which formed in Late Tertiary Period or early The speculation about selected section developed from paleosols in-situ was eliminated basically by use of such morphological features as hue, structure of sediment, and lacking in bioturbation, and roots Higher content of CaCO3 and lower ratio of free Fe (DCB-Fe) to total Fe with less than 20 % illustrated that low degree of the sources of section in weathering and showed that the climate quite dry and warm while selected section formed at that time The geochemical characteristics of rare earth elements and microelements in selected section indicated that the sediments of selected section was transported and allochthonousFor rare studies on the change before and after paleosols were buried, and the morphological features of paleosols disappeared or varied due to diagenesis, so it was difficult to discuss the derivation of terrestrial sediments by morphological features of deposition section Therefore, some other unchangeable and preserved proofs were needed to identify paleosols, of which geochemical features were effective 

关 键 词：沉积物 古土壤 原位沉积 异地搬运 

分 类 号：P534.51[天文地球—古生物学与地层学] S151.1[天文地球—地质学]