The
geochemical attributes of paleosols have been used to estimate
paleoenvironmental and paleoclimatic conditions through much of the
Phanerozoic. Here, Michel et al. use plane-polarized
and cathodoluminescence petrography, electron microprobe, and stable isotope
ratio mass spectrometry observations of paleosols from Permo-Carboniferous
strata of the Lodève Basin, France to evaluate the role of post-depositional
alteration on geochemistry of paleosols. The results illustrate that
macrofeatures within paleosols are retainend and can be used for paleoclimate
reconstruction; however, geochemical signatures are neither reflective of soil
formation nor appropriate to use in paleoclimate reconstruction due to
diagenetic alterations. Yet, the paleosol carbonate cements and matrix clays
preserve information that reflects a complicated calcite-cement stratigraphy
recorded in nodules, and quartz, barite, dolomite, and Fe-rich calcite
cementation. These results emphasize that pedogenic nodules, rhizoliths,
and paleosol matrix should systematically evaluated for diagenetic alteration
prior to applying geochemical based proxies to reconstruct paleoclimate.
Paleosol diagenesis and its deep-timepaleoenvironmental implications, Pennsylvanian–Permian Lodève Basin, France by Lauren A. Michel, Neil J. Tabor,
and Isabel P. Montañez
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