Abstract

Distribution of total and acid-soluble lead in five major soil types and soil-forming rocks have been studied in the Selenga River delta, the largest affluent of Lake Baikal. A low content of this element in soil-forming rocks (6.0 mg/kg on the average) along with the local soil-geochemical conditions is responsible for its small amount in soils. The bulk lead content in the topsoil (0–20 cm) layer varies from 3 to 17 mg/kg (the mean is 10 mg/kg), which is lower than the maximum permissible concentration and the natural abundance (clarke) of lead in soils of the world. The lead content in swampy and soddy alluvial soils is two times higher than in meadow alluvial and gray forest soils and in sands under pine forests. Differences in the lead content in soils on the left and right banks of the Selenga River delta have been revealed. The content of acid-soluble lead varies within 24–68% of the total lead content in alluvial swampy and alluvial meadow soils, within 15–43% in alluvial soddy soils, and within 11–26% in gray forest soils and sands under pine forest. The distribution pattern of lead in the vertical soil profile is eluvial–illuvial in alluvial swampy and alluvial meadow soils and sands under pine forest and accumulative–eluvial–illuvial in soddy alluvial and gray forest soils. Lead accumulation in the organic and gley horizons of alluvial swampy and alluvial meadow soils is revealed. In alluvial soddy and gray forest soils with relatively uniform particle-size and mineralogical composition, lead is evenly distributed in the soil profile with a particular accumulation in the top sod layer. The dependence on soil properties is slight for the total lead content and is somewhat stronger for acid-soluble lead. The data obtained may be used for biogeochemical monitoring in the Baikal region.

中文翻译：

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塞伦加河三角洲土壤中的铅

摘要

在贝加尔湖最大的富裕地区塞伦加河三角洲，研究了五种主要土壤类型和土壤形成岩石中总铅和酸溶性铅的分布。在土壤形成岩石中该元素的含量较低（平均6.0 mg / kg），加上当地的土壤地球化学条件，导致其在土壤中的含量很少。表土（0–20 cm）层中的总铅含量为3至17 mg / kg（平均为10 mg / kg），低于铅的最大允许浓度和自然丰度（克拉）。世界的土壤。沼泽和湿润冲积土壤中的铅含量是草甸冲积和灰色森林土壤以及松树林下的沙子中的铅含量的两倍。揭示了塞伦加河三角洲左岸和右岸土壤中铅含量的差异。冲积沼泽和冲积草甸土壤中酸溶性铅的含量在总铅含量的24％至68％之间，冲积水质土壤中的铅含量在15％至43％之间，灰色森林土壤和松树下的沙子在11％至26％之间森林。铅在垂直土壤剖面中的分布模式在松树林下的冲积沼泽和冲积草甸土壤和沙地中为冲积-冲积，在草质冲积和灰色森林土壤中为累积-冲积-冲积。揭示了在冲积沼泽和冲积草甸土壤的有机层和格利层中铅的积累。在颗粒大小和矿物组成相对均一的冲积性草皮和灰色森林土壤中，铅均匀地分布在土壤剖面中，并且在草皮的顶层有特定的积累。总铅含量对土壤特性的依赖性很小，而酸溶性铅的依赖性更强。获得的数据可用于贝加尔湖地区的生物地球化学监测。