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Iron oxides and rare earth elements in the clay fractions of a soil chronosequence in southern S pain
Author(s) -
MartínGarcía J. M.,
SánchezMarañón M.,
Calero J.,
Aranda V.,
Delgado G.,
Delgado R.
Publication year - 2016
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/ejss.12377
Subject(s) - chronosequence , goethite , geology , mafic , geochemistry , soil water , clay minerals , mineralogy , chemistry , soil science , adsorption , organic chemistry
Mineralogical ( XRD ), crystallochemical ( DXRD ), geochemical ( ICP ‐ms and ICP‐AES ) and spectroscopic colour ( DRS ) properties of the clay fractions confirmed that five soils (a F luvisol, two C alcisols and two L uvisols) on fluvial terraces in southern S pain form a genuine chronosequence that extends back to 600 ka. Analyses showed that goethite was more abundant than haematite. Both iron (hydr)oxide contents and A l substitution in goethite (mole %) increased with soil age. The F e in the (hydr)oxides came from the transformation of illites to smectite + mixed‐layer phyllosilicates. Rare earth element contents correlated with a mafic alteration index and with soil age. Soil colours reflected variation in the proportions of calcite and iron (hydr)oxides, and became redder with age. Most soil properties were fitted by logarithmic chronofunctions that approach asymptotes at 70–100 ka. Highlights A chronosequence is confirmed from the soil of fluvial terraces in southern S pain. Goethite exceeds haematite throughout and increases with soil age. Rare earth elements correlate with a mafic alteration index and soil age. Most soil attributes show logarithmic chronofunctions with asymptotes at 70–100 ka.