RT Journal Article
T1 Geochemistry of bentonites: A statistical analysis of trace element distribution in smectites
A1 Lorenzo Hernández, Adrián
A1 Sánchez Santos, José Manuel
A1 Rivas, María Jesús
A1 García Romero, Emilia
A1 Suárez Barrios, Mercedes
AB This work focuses on the study of the trace elements allocation in smectites throughout the statistical analysis of geochemical data corresponding to a very wide group of pure or almost bentonite samples. Data of trace elements contents corresponding to both analysed samples and bibliographic references were treated with different statistical analysis such as Partial Least Squares Discriminant Analysis (PLS-DA), Wilcoxon-Mann-Whitney rank sum test (WMW test). A clear relationship between trace elements and smectite crystallochemistry was evidenced from the PLS-DA results because the contents in certain the trace element separated the dioctahedral smectites from the trioctahedral smectites. In addition, the WMW test indicated that dioctahedral smectites preferentially accumulate Er, Eu, Gd, Sm, Tb, Nd, Ga, Dy, Ho, Tm, Be, Y, Yb, La, Pb, Ce, Lu, Pr, Hf, Bi, Zr, Zn, Nb, In, Th, Ta, Sn, and Ge, while trioctahedral smectites preferentially accumulate As. Complementary analysis by X-Ray Micro-Fluorescence and a study after homoionization were done to help to discuss these results. According to these results, the presence of these elements as interlayer cations or their adsorption at layer edges has been excluded. In addition, external factors such as impurities and the geological origin of bentonites have been discussed and ruled out as influencing factors that could invalidate the obtained results. An evaluation of atomic parameters for trace elements indicates that As, with an effective cationic radius of 33.5 pm for coordination number CN = 4, can be allocated in tetrahedral positions, whereas the remaining elements can occupy octahedral positions.
PB Elsevier
SN 0169-1317
YR 2024
FD 2024-09-01
LK https://hdl.handle.net/20.500.14352/104971
UL https://hdl.handle.net/20.500.14352/104971
LA eng
NO Lorenzo, Adrián, et al. «Geochemistry of Bentonites: A Statistical Analysis of Trace Element Distribution in Smectites». Applied Clay Science, vol. 257, septiembre de 2024, p. 107449. DOI.org (Crossref), https://doi.org/10.1016/j.clay.2024.107449
NO Junta de Castilla y León
NO Ministerio de Ciencia e Innovación
DS Docta Complutense
RD 12 abr 2025