GEMAS – Chemistry of Europe’s Agricultural soils, Single element maps, Bi - Bismuth

GEMAS (Geochemical Mapping of Agricultural and Grazing Land Soil in Europe) is a cooperative project between the Geochemistry Expert Group of EuroGeoSurveys and Eurometeaux. In total, more than 60 international organisations and institutions worldwide were involved in the implementation of the project. During 2008 and 2009, a total of 2219 samples of agricultural (arable land soils, 0 – 20 cm, Ap samples) and 2127 samples of grazing land (pasture land soils, 0 – 10 cm, Gr samples) soil were collected at a density of 1 site/2 500 km² each from 33 European countries, covering an area of 5,600,000 km². All samples were analysed for 52 chemical elements after an aqua regia extraction, 41 by XRF (total), TC and TOC. In addition, the agricultural soil samples were analysed for 57 elements in a mobile metal ion (MMI®) extraction and Pb isotopes. All analytical results were subject to tight external quality control procedures. The GEMAS project thus provides for the first time fully harmonised data for element concentrations and bioavailability of the elements at the continental (European) scale. The downloadable files present the areal distribution of the element contents determined by different analytical methods in the shape of colour shaded contour maps with a classification in 7 and 72 levels each.GEMAS（欧洲农业与牧场土壤地球化学制图，Geochemical Mapping of Agricultural and Grazing Land Soil in Europe）是由EuroGeoSurveys地球化学专家组与Eurometeaux合作开展的项目。该项目的实施总计吸引了全球60余家国际组织与科研机构参与。2008年至2009年间，项目团队从欧洲33个国家的总计560万平方千米范围内，以每2500平方千米1个采样点的密度，采集了2219份农业土壤样本（耕地土壤，0~20厘米深度，即Ap样本）与2127份牧场土壤样本（牧草地土壤，0~10厘米深度，即Gr样本）。所有样本均经王水消解后，针对52种化学元素开展检测，其中41种元素通过X射线荧光光谱法（XRF，全量）、总碳（TC）与总有机碳（TOC）完成定量分析。此外，农业土壤样本还通过可移动金属离子（MMI®）萃取法针对57种元素以及铅同位素开展了检测。所有分析结果均经过严格的外部质量控制流程审核。因此，GEMAS项目首次在欧洲大陆尺度上提供了统一规范的元素浓度与元素生物有效性数据。可下载文件以彩色分层等值线图的形式展示了不同分析方法测得的元素含量空间分布，每种分类方案分别设置7级与72级分级标准。