The Miocene Source-to-Sink Evolution of Fibrous ClayMinerals in Hyperalkaline Playa-Lakes, Duero Basin (Central Spain)
Metadatos
Mostrar el registro completo del ítemAutor
del Buey, Pablo; Sanz Montero, María Esther; Rodríguez Aranda, Juan Pablo; Sánchez-Román, Mónica; Nieto García, FernandoEditorial
MDPI
Materia
TEM-AEM palygorskite chlorite
Fecha
2025-01-05Referencia bibliográfica
del Buey, P. et. al. Minerals 2025, 15, 50 [https://doi.org/10.3390/min15010050]
Patrocinador
Spanish Ministry of Science and Innovation through the National Research Project PID2021-123735OB-C22 along with financial support from the Dutch Research Council project OCENW.KLEIN.037Resumen
Palygorskite is assumed to be the predominant clay mineral in playa-lakes, where
it may be detrital or authigenic in origin. Discriminating between detrital and authigenic
clays is crucial to elucidate paleoenvironmental conditions in lacustrine deposits. This study
provides insight into the sedimentary evolution of clay minerals from source, lacustrine
Miocene marlstones and mudstones, to sink, represented by three recent hyperalkaline
playa-lakes in Central Spain. XRD, TEM, and AEM analyses show concomitant detrital
and authigenic palygorskites in the three playa-lakes. The inherited palygorskites exhibit
degradation features, larger widths, and common and ideal compositions, in contrast to
neoformed particles. The latter are narrower. Depending on the hydrochemical composition
of each playa-lake, neoformed palygorskites are enriched in a different octahedral cation
(Al2O3, MgO, and Fe2O3). Iron-rich palygorskites are only formed in association with
authigenic saponites in one of the playa-lakes. The same effect of magnesium competition
between smectite and palygorskite is observed in Miocene mudstones, where palygorskite
is relatively enriched in iron. In hyperalkaline, seasonal playa-lakes lying in the vicinity,
slight physicochemical differences play a crucial role in the crystallochemical composition
of authigenic palygorskites, highlighting the use of this mineral as a geochemical proxy.