• <mark id="l0x4h"></mark>

      <u id="l0x4h"></u>
        <ins id="l0x4h"></ins>

      1. <bdo id="l0x4h"></bdo>
      2. 黃土高原南緣S5-1古土壤中膠膜的特征及其環境意義
        DOI:
        作者:
        作者單位:

        華中農業大學

        作者簡介:

        通訊作者:

        中圖分類號:

        S151

        基金項目:

        國家自然科學基金項目(面上項目,重點項目,重大項目)


        Characteristics of cutan in the S5-1 paleosol on the southern Chinese Loess Plateau and its environmental significance
        Author:
        Affiliation:

        Fund Project:

        • 摘要
        • |
        • 圖/表
        • |
        • 訪問統計
        • |
        • 參考文獻
        • |
        • 相似文獻
        • |
        • 引證文獻
        • |
        • 資源附件
        • |
        • 文章評論
          摘要:

          以中國黃土高原南緣武功地區S5-1古土壤為研究對象,對比分析其膠膜與基質土壤的礦物學與地球化學特征,明確古土壤結構體表面深色膠膜的類型及其環境意義。拉曼光譜中400-800 cm-1的寬峰可能是多種鐵和錳(氫)氧化物的混合光譜。錳和游離鐵(Fed)的相對富集證實結構體表面的深色膠膜為鐵錳膠膜,這說明在S5-1古土壤發育期間經歷了周期性的氧化還原。S5-1古土壤中的淀積粘化過程導致其容重大、總孔隙度低,降低土層透水性,易發生季節性淹水,為鐵錳膠膜的形成提供有利環境條件。然而,因S5-1古土壤中鐵和錳的分離與積累時間短,其Mn/Fe比值較低,未達到亞熱帶地區典型鐵錳膠膜中的水平。Fed/Fet比值反映的膠膜與基質土壤之間化學風化的差異未體現在礦物組成上,二者的原生礦物與粘土礦物組成基本一致。S5-1古土壤中鐵錳膠膜的存在進一步證實了發育期間中國黃土高原南緣盛行亞熱帶氣候。

          Abstract:

          To provide more insight in the characteristics of the cutan in the S5 and its environmental significance, the mineralogy and geochemical composition of the cutan and matrix soil in the S5-1pedon at the Wugong section on the southern Chinese Loess Plateau (CLP) was investigated. The broad band between 400-800 cm-1 in the Raman spectrum of the dark cutan was attributed to the groups of Fe and Mn hydroxide/oxide. Enrichment of Mn and free iron (Fed) in the cutan verified the presence of Fe-Mn cutan in the S5-1 pedon which signified a periodic reduction under waterlogged conditions during the pedogenesis of S5-1 pedon on the southern CLP. The low permeability of S5-1 pedon as a result of lessivage of clay fraction characterized by high bulk density and low total porosity made the development of a seasonal perched water table possible. It provided favorable environmental conditions for the formation of Fe-Mn cutan. However, the low Mn/Fe ratio in the cutan suggested that the separation and accumulation of iron and manganese in the S5-1 pedon was not up to the level of typical Fe-Mn cutan from subtropical regions. Silicate minerals in the Fe-Mn cutan was was almost identical to the matrix soil. The difference of chemical weathering between the cutan and the matrix soil reflected by the Fed/Fet ratio was not epitomized by the mineralogical composition. While the S5-1 developed a subtropical climate prevailed on the southern CLP was further corroborated by the occurrence of Fe-Mn cutan.

          參考文獻
          相似文獻
          引證文獻
        引用本文
        分享
        文章指標
        • 點擊次數:
        • 下載次數:
        • HTML閱讀次數:
        • 引用次數:
        歷史
        • 收稿日期:2020-07-12
        • 最后修改日期:2020-08-31
        • 錄用日期:2020-09-04
        • 在線發布日期:
        • 出版日期:
        牌九游戏