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作 者:潘根兴[1] 黄瑞采[1] 丁瑞兴[1] 熊德祥[1] 韩高原
机构地区:[1]南京农业大学自然资源与环境科学系
出 处:《第四纪研究》1995年第3期249-257,共9页Quaternary Sciences
基 金:国家教委博士点基金
摘 要:本文从淮北白浆土的剖面二段性出发,根据土壤性质的剖面变化,剖析了这种土壤中存在着的土壤发生间断性,并通过化学成分、粘土矿物组成、铁锰结核的地球化学、土壤薄片及石英颗粒形态、抱粉以及年龄等分析、鉴定和测定,结合土壤与地貌的关系,揭示了这种土壤上、下部土体间不同的发育状态。研究表明,淮北白浆土的形成并非全新世以来某种单一成土过程的结果,而是本区晚第四纪以来不同阶段地貌演变和气候变化造成的土壤演变的外在表现,它还记录了本区多次抬升-剥蚀-堆积-土壤发育的交替演变。There are over 100 000 hactares of albic soils in hills and mounds betweenShangdong and Jiangsu Provinces.Their average profile is constituted by two parts.The upper part includes a gray, silt sandy and weakly structured anthropic epipedonand underlying albic soils,locally with bottom gravels cemented with dark brownoxyhydrates, and the lower part is generally brownish clay with well developed prismatic structure, transiting to weathered metamorphic rocks, dominantly gneiss. Theformation of albic soils used to be attributed to reduction-bleaching of water detained by the impermeable lower part. Nevertheless, pseudo-conformability withinprofiles and lack of reduction phenomena imply that the formation of albic soilswas a discontinuous process, which could be related to Quaternary environmentalchanges.Analyses of particle size, placer minerals and main chemical compositions revealthe discontinuity of sedimentation and pedogenesis between the upper and lowerparts in albic soil-bearing profiles. The surface morphology of quartz grains showsthat the upper part originated from younger sediments and the lower part from older in situ weathered rocks. The TL dating of quartz further shows that the upperwas deposited at the end of the last glacial and the lower part formed in the interglacial period between the Lushan glacial and the Dan glacial. Soils in the upperpart contains abundant ferrugineous concretions, especially at the bottom, consists ofdetrital minerals dominated by hydromica (illite), is weak both in weathering andin differentiation and gelatification. On the other hand, soils in the lower partcontains only a few ferric nodules, consists of clay minerals from illite to kaolinite(in some places, dominated by kaolinite with heamatite), and is varying in weathering and strong in differentiation and gelatification.According to geomorphic data, in combination with our field observation, soils'in the lower part is the erosion residue of paleosols formed during the period ofMiddle Pleistocene to Late Pleistocene. Th
分 类 号:S155.26[农业科学—土壤学] P531[农业科学—农业基础科学]
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