西藏高原土壤多元发生的微形态研究

自上新世末以来,随着西藏高原的隆起和多次冰川作用,作为成土因素的气候、植被、地形、水文等条件发生了剧烈的演变,从而对西藏高原土壤的发生、演化产生重要的影响.土壤大形态研究表明,西藏高原土壤广泛地显示有明显的组合剖面,突出表现在这些土壤剖面中存在有黄棕或棕带红色的、与其上下土层无发生上联系的、在暖湿气候条件下形成的土层;或者在某些现代陆成上壤剖面中存在有水成土的残遗特征等,这些形态特征在很大程度上说明了西藏高原土壤多元发生的客观存在.

MICROMORPHOLOGICAL STUDY WITH SPECIAL REFERENCE TO SOIL POLYGENESIS OF XIZANG (TIBET) PLATEAU

The soil-forming factors on Xizang Plateau,such as climate,vegetation,topography and hydrographical conditions have changed greatly since the end of Pliocene as the result of uplifting of the Plateau.It exerted deep influence on soil genesis and evolution in this regicn.The field investigation showed that soils bearing composite profile with paleosol layer are widely spreaded.The morphological characteristics of these composite soil profiles may indicate,to a great extent,the polygenetic processes of soils on the Plateau.To give evidence,micromorphological study of soils bearing paleosol layers has been carried out.Thin section observation indicates that the polygenetic characteristics of soils are closely related to the historical natural evolution of Xizang Plateau.