Ion Adriana, Cosac Ana
Geological Institute of Romania, Radiometry Laboratory, 1 Caransebes st., RO-012271, Bucharest, Romania.
Heliyon. 2023 Feb 24;9(3):e13976. doi: 10.1016/j.heliyon.2023.e13976. eCollection 2023 Mar.
This paper gives an overview of the REEs distribution in topsoil from Ditrău Alkaline Massif area under influence of basic natural factors (parent material and soil acidity). Seventy-six soil samples were collected in accord with the most representative bedrock types and concentrations of the elements were determined using inductively coupled plasma mass spectrometry. The ΣREEs contents in soil developed on alkaline rocks ranges from 52.59 to 579.20 μg/g, with an average value of 235.76 μg/g, significantly higher than the average value of Earth's crust (179.7 μg/g). Y content varies between 5.50 and 58.80 μg/g with an average of 21.67 μg/g. The soils are enriched in LREEs (La to Eu) and depleted in HREEs (Gd to Lu) and Y. This trend is expressed by the wide variations of the LREEs/HREEs, (La/Yb), (La/Sm) and (Gd/Yb) ratios. The REE chondrite - normalized plots show for most soils strongly negative anomalies for cerium and europium and positive anomalies for gadolinium and dysprosium. The pH of soils is generally acidic to weakly acidic and has an insignificant role in REEs fractionations in soil. The spatial distribution of REEs is strongly related to the lithology of the study area, displaying minor to negligible effects of enrichment factors and a low geoaccumulation index, corresponding to the lack of anthropic contamination. The distribution of the elements in topsoil tends to mimic elemental accumulation in the parental bedrock, with a potential to highlight mineralized zones.
本文概述了迪特劳碱性地块地区表土中稀土元素在基本自然因素（母质和土壤酸度）影响下的分布情况。根据最具代表性的基岩类型采集了76个土壤样本，并使用电感耦合等离子体质谱法测定了元素浓度。在碱性岩石上发育的土壤中，总稀土元素含量范围为52.59至579.20μg/g，平均值为235.76μg/g，显著高于地壳平均值（179.7μg/g）。钇含量在5.50至58.80μg/g之间变化，平均值为21.67μg/g。这些土壤富含轻稀土元素（镧至铕），贫重稀土元素（钆至镥）和钇。这种趋势通过轻稀土元素/重稀土元素、（镧/镱）、（镧/钐）和（钆/镱）比值的广泛变化来体现。稀土球粒陨石标准化图显示，大多数土壤中铈和铕有强烈的负异常，钆和镝有正异常。土壤的pH值一般呈酸性至弱酸性，在土壤中稀土元素分馏中作用不显著。稀土元素的空间分布与研究区域的岩性密切相关，富集因子的影响较小至可忽略不计，地累积指数较低，这表明缺乏人为污染。表土中元素的分布倾向于模仿母岩中的元素积累，有可能突出矿化带。
