摘要
江苏宜溧地区分布有400km^2多的富硒土壤,并产出天然富硒稻米.通过系统分析研究宜溧富硒稻米产地的稻米、土壤、岩石、水样的Se等元素地球化学数据,探讨了控制宜溧地区富硒稻米产出的主要地质环境及地球化学背景因素,总结了Se等元素在米-土-岩之间的分布迁移特征.结果显示：（1）宜溧地区产出的富硒稻米主要受富硒耕地控制,稻米Se与耕地土壤Se、Corg.之间存在显著正相关性,米Se与土Se的相关系数R=0.81,土壤Se≥0.5mg/kg的耕地中富硒稻米检出率为100%;（2）二叠系煤系地层中的杂色泥质粉砂岩、页岩是主要富硒原岩,其平均Se含量达到17.22mg/kg,比当地土壤中Se高出5倍以上.富硒原岩沉积厚度越大,其上覆土壤的Se含量越高;（3）上述富硒岩层中夹杂一层几到几十厘米厚的铁锰结核透镜状沉积物,富集Fe、Mn、Cd、S、P等,其风化形成土壤可能富集Cd,但富硒稻米中未检测到Cd超标;（4）耕地土壤中有效Se小于0.02mg/kg,有效Se占土壤Se的比例为0.16%-2%.富硒耕地土壤总体偏酸性,其pH一般介于4.6-6.5,富硒原岩更偏酸性,其pH一般介于4.2-5.5;（5）Se从源头向耕地迁移也是一个不断均匀化的过程,地势、气候条件、断层等对富硒耕地的分布有影响,山间盆地、沟谷、山前平原是形成天然富硒耕地的主要场所,特定断层可成为天然富硒耕地的边界.
There exist abundant Se-rich soil resources over 400 km^2 in the Yili area, Jiangsu Province, and a part of natural Se-richrice has been produced in this area. By systematically studying and analyzing newly-obtained elemental geochemical data from thetypical samples about rice seeds, soil, rock and soil solution related to Se-rich rice origin, this paper discusses the main controlling factors and geological environment or geochemical background for producing the natural Se- rich rice in the Yili area, andsummarizes distribution and migration characteristics of some trace elements such as Se within rice as well as soil and rock. Someconclusions have been reached： （1） Se concentration in rice is significantly correlated to Se and TOC in soil, with the correlationcoefficient （R） being 0.81. Detection rate of Se-rich rice is 100% when Se concentration is more than 0.5 mg/kg in soil; （2） Permiancoal- bearing strata seem to be main primitive sources to form Se- rich soil, and the variegated argillaceous siltstone and shalewithin the strata are important Se-rich rocks, and the average Se concentration is 17.22 mg/kg in these rocks, which is more than 5times higher than the average Se concentration in the local soil; and there are some obvious positive correlation between rockthickness and Se concentration in its overlying soil： where the sedimentary thickness of the Se- rich rock increases, the Seconcentration is higher in the overlying soil layer; （3） The above-mentioned Se-rich rock formation includes a layer of iron andmanganese nodule sediments lenticular in form, its thickness is about 5-30 cm, and there are abundant Fe, Mn, Cd, S, P and someother elements in the nodule sediments; the weathering and transferring process to form soil may contain a part of Cd, but the Cdthat exceeds the value of the standard sample has not been yet detected in those relevant Se-rich rice seeds; （4） the available Seconcentration is lower than 0.02 mg/kg in the cultivated soil, and the ratio of the available Se
作者
廖启林
任静华
许伟伟
崔晓丹
金洋
李文博
范健
朱伯万
LIAO Qi-lin REN JING-hua XUWei-wei CUI Xiao-dan JIN Yang LIWen-bo FAN Jian ZHU Bai-wan(Geological Survey of Jiangsu Province, Nanjing 210018, Jiangsu, China)
出处
《中国地质》
CAS
CSCD
北大核心
2016年第5期1791-1802,共12页
Geology in China
基金
江苏省科技支撑计划--社会发展类BE2013720课题
江苏省地质勘查基金项目"太湖周边优质农业地质资源调查及开发应用示范"共同资助~~
关键词
富硒稻米
地质背景
地球化学
宜溧地区
江苏
Se-rich rice
geological background
geochemistry
Yili area
Jiangsu Province
