摘要
在综合分析江苏区域生态地球化学调查和局部土地质量地球化学评估等相关数据的基础上,通过元素含量地球化学参数统计、相关分析和R型聚类分析等方法,探讨了江苏富硒土壤的主要成因类型及元素相关性特征。研究结果显示,江苏富硒土壤主要分为母岩型、沉积型、叠加型3大成因类型:母岩型富硒土壤源于富硒岩石,属于典型的原生富硒土壤,具有厚度大(最大厚度>150 cm)、Se含量高(多介于0.5~0.8 mg/kg之间)、与多数重金属元素无显著相关性等特点,其生态环境质量相对更优越,开发利用价值相对最高,岩石中Se的富集程度以及富硒岩层的产状、厚度、分布与地形条件是制约该类型富硒土壤生成与利用的关键因素;沉积型富硒土壤缘于特殊第四纪沉积作用,潟湖相沉积物是其基本成土母质,富硒土壤形成要经历成土母质初始富集、成土过程分选富集和成土后期表生富集3个阶段,土壤Se含量多在0.3 mg/kg左右,厚度多在30 cm左右,分布范围相对较大,土壤中Se与OM之间、多个元素对之间都具有显著正相关性,OM、pH、Eh、CEC、黏土矿物和Fe-Mn氧化物含量等都是制约该类型土壤Se迁移富集的重要因子,元素特征组合为Se-OM-N-CEC-Mg;叠加型富硒土壤缘于人为活动,其形成与自然成土过程或第四纪沉积作用基本无关,施肥、“三废”排放、河泥、粉煤灰扩散等可能是导致局部土壤富硒的主要因素,土壤Se含量一般为0.5~0.6 mg/kg,分布不均匀,富硒土壤厚度一般<20 cm,元素特征组合为Se-Hg-As-Ca-pH,富硒土壤中As、Cd、Hg、Pb等重金属相对富集,开发利用此类富硒土壤须持审慎的态度。
Based on the integrated analysis of relevant data of regional ecological geochemical survey and local land quality geochemical assessment in Jiangsu Province,the main origin types and element correlation characteristics of selenium-rich soils in Jiangsu Province were discussed by means of geochemical parameter statistics of element content,correlation analysis and R-type cluster analysis.The results show that the Se-rich soils in Jiangsu are mainly divided into three genetic types of parent rock type,sedimentary type and later overlying type.Firstly,Se-rich soil of the parent rock type is a typical native Se-rich soil originating from Se-rich rocks.It is featured with large thickness(the thickest is greater than 150 cm),high Se content(mostly between 0.5 and 0.8 mg/kg),and has no significant correlation with most heavy metal elements.Its ecological environment quality is relatively superior,and its development and utilization value is relatively higher.The enrichment degree of Se in rocks,the occurrence,thickness,distribution and topographic conditions of selenium-rich rock strata are the key factors that restrict the formation and utilization of selenium-rich soil.Secondly,sedimentary selenium-rich soil is due to special Quaternary sedimentation,and lagoon sediments are its basic parent material.The formation of selenium-rich soil goes through three stages:initial enrichment of parent material,sorting and enrichment in the process of soil formation,and epigenetic enrichment in the later stage of soil formation.The content of Se in soil is mostly about 0.3 mg/kg,the thickness is mostly about 30 cm,and the distribution range is relatively large.There were significant positive correlations between Se and OM,and between multiple element pairs in soil.OM,pH,Eh,CEC,clay minerals and Fe-Mn oxide content were important factors restricting the migration and enrichment of soil Se,and the characteristic element combination was SE-OM-N-CEC-Mg.Thirdly,Se-rich soil of later overlying type is due to human activities,and its formation has little to do with soil formation process or Quaternary sedimentation.Fertilization,discharge of three wastes,river mud and fly ash diffusion may be the main factors leading to local Se-rich soil,and its content of Se in soil is generally 0.5-0.6 mg/kg,with uneven distribution.The thickness of selenium-rich soil is generally less than 20 cm,and the characteristic element combination is Se-Hg-As-Ca-pH.As,Cd,Hg,Pb and other heavy metals are relatively enriched in selenium-rich soil of later overlying type,so the development and utilization of such selenium-rich soil should be cautious.
作者
廖启林
金洋
崔晓丹
黄顺生
任静华
范健
杜维真
刘玮晶
徐宏婷
汪子意
Liao Qilin;Jin Yang;Cui Xiaodan;Huang Shunsheng;Ren Jinghua;Fan Jian;Du Weizhen;Liu Weijing;Xu Hongting;Wang Ziyi(Technology Innovation Center for Ecological Monitoring&Restoration Project on Land(Arable),Ministry of Natural Resources,Nanjing 210018,Jiangsu,China;Geological Survey of Jiangsu Province,Nanjing 210018,Jiangsu,China)
出处
《地质学刊》
CAS
2023年第4期390-401,共12页
Journal of Geology
基金
江苏省自然资源发展专项资金(海洋科技创新)项目“沿海滩涂资源保护保护与开发利用关键技术研发”(JSZRHYKJ202117),江苏省自然科学基金面上项目(BK20171496)。
关键词
富硒土壤
成因类型
元素
相关分析
江苏
Se-enriched soil
origin type
element
correlation analysis
Jiangsu Province
