TY - JOUR
T1 - The Formation of Clay-Enriched Horizons by Lessivage
AU - Calabrese, Salvatore
AU - Richter, Daniel D.
AU - Porporato, Amilcare Michele M.
N1 - Funding Information:
This work was supported through the USDA Agricultural Research Service cooperative agreement 58-6408-3-027; National Science Foundation (NSF) grants CBET-1033467, EAR-1331846, FESD-1338694, and EAR-1316258; and the Duke WISeNet grant DGE-1068871. The authors declare no conflict of interest. Data used in this study are available at http://criticalzone.org/calhoun/data/datasets/. Valuable remarks from the anonymous referees are gratefully acknowledged.
Funding Information:
This work was supported through the USDA Agricultural Research Service cooperative agreement 58-6408-3-027; National Science Foundation (NSF) grants CBET-1033467, EAR-1331846, FESD-1338694, and EAR-1316258; and the Duke WISeNet grant DGE-1068871. The authors declare no conflict of interest. Data used in this study are available at http://criticalzone.org/calhoun/data/ datasets/. Valuable remarks from the anonymous referees are gratefully acknowledged.
Publisher Copyright:
©2018. American Geophysical Union. All Rights Reserved.
PY - 2018/8/16
Y1 - 2018/8/16
N2 - Soils with argillic horizons comprise more than 25% of the Earth's surface. Although their origin is still debated, lessivage is often invoked to explain them, but the long timescales involved hinder its direct experimental verification. We present a parsimonious model of clay transport, formulated for long timescales over which lessivage is modeled stochastically, complemented by detailed field observations. This probabilistic description allows us to predict the clay profile, the depth of the Bt horizon from the surface, and the mean clay residence time. The results are tested with field measurements at different locations in the Calhoun Critical Zone Observatory. Dimensional analysis unveils two dimensionless parameters governing lessivage dynamics, leading to a classification based on erosion rates and lessivage characteristics. We identify static and eluviated regimes, in which erosion or eluviation prevails, and an illuviated regime, in which the balance between lessivage and erosion brings about the formation of a Bt horizon.
AB - Soils with argillic horizons comprise more than 25% of the Earth's surface. Although their origin is still debated, lessivage is often invoked to explain them, but the long timescales involved hinder its direct experimental verification. We present a parsimonious model of clay transport, formulated for long timescales over which lessivage is modeled stochastically, complemented by detailed field observations. This probabilistic description allows us to predict the clay profile, the depth of the Bt horizon from the surface, and the mean clay residence time. The results are tested with field measurements at different locations in the Calhoun Critical Zone Observatory. Dimensional analysis unveils two dimensionless parameters governing lessivage dynamics, leading to a classification based on erosion rates and lessivage characteristics. We identify static and eluviated regimes, in which erosion or eluviation prevails, and an illuviated regime, in which the balance between lessivage and erosion brings about the formation of a Bt horizon.
KW - Bt horizon
KW - clay profiles classification
KW - clay translocation
KW - formation of clay-enriched horizons
KW - lessivage model
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U2 - 10.1029/2018GL078778
DO - 10.1029/2018GL078778
M3 - Article
AN - SCOPUS:85052569950
SN - 0094-8276
VL - 45
SP - 7588
EP - 7595
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 15
ER -