TY - JOUR
T1 - U-series isotope constraints on the rates of aeolian-impacted basaltic weathering under tropical climate
AU - Ming, Guodong
AU - Huang, Jingyi
AU - Sheng, Jiaru
AU - Gong, Yingzeng
AU - Guo, Jiye
AU - Yu, Huimin
AU - Cheng, Wenhan
AU - Lundstrom, Craig C.
AU - Huang, Fang
N1 - Publisher Copyright:
© 2024 Elsevier B.V.
PY - 2025/2
Y1 - 2025/2
N2 - The chemical weathering of basalt rocks is crucial for stabilizing Earth's habitability and carbon cycle. Currently, the soil chemistry and weathering rates of basalt under significant aeolian influence are not fully understood. This study addresses this gap by investigating the U geochemistry and regolith production rates in a highly weathered basalt profile in Southern China. The εNd(0) values decrease from the bedrock sample (4.68) to the top soils (0.94), indicating aerosol input from the top. Dust accretion decrease downward and significantly affects the vertical distribution of U (R2 = 0.86), while the chemical mobilization of U is controlled by binding with Fe oxides-organic matter complexes (R2 = 0.33). The influence of dust accretion diminishes to insignificant (less than 9 % for U amount) below 330 cm, meeting the model's criteria for estimating U-series isotope-based regolith production rates. The estimated regolith production rates for depths of 445 cm, 370 cm, and 330 cm are ∼ 10 m/Myr, ∼ 5.5 m/Myr, and ∼ 3 m/Myr, respectively. These rates decrease with increasing depth, illustrating the depletion of soluble materials as the weathering profile thickens. CO2 consumption fluxes calculated from soil chemistry (< 193 × 103 mol/km2/yr) are lower than those from river chemistry. Regolith development in the Leizhou Peninsula may account for < 25 % of total chemical erosion, suggesting significant hidden erosion processes. These observations indicate that other potential weathering sources in aquifers and steeper terrains should be independently estimated when assessing basin-scale CO2 consumption.
AB - The chemical weathering of basalt rocks is crucial for stabilizing Earth's habitability and carbon cycle. Currently, the soil chemistry and weathering rates of basalt under significant aeolian influence are not fully understood. This study addresses this gap by investigating the U geochemistry and regolith production rates in a highly weathered basalt profile in Southern China. The εNd(0) values decrease from the bedrock sample (4.68) to the top soils (0.94), indicating aerosol input from the top. Dust accretion decrease downward and significantly affects the vertical distribution of U (R2 = 0.86), while the chemical mobilization of U is controlled by binding with Fe oxides-organic matter complexes (R2 = 0.33). The influence of dust accretion diminishes to insignificant (less than 9 % for U amount) below 330 cm, meeting the model's criteria for estimating U-series isotope-based regolith production rates. The estimated regolith production rates for depths of 445 cm, 370 cm, and 330 cm are ∼ 10 m/Myr, ∼ 5.5 m/Myr, and ∼ 3 m/Myr, respectively. These rates decrease with increasing depth, illustrating the depletion of soluble materials as the weathering profile thickens. CO2 consumption fluxes calculated from soil chemistry (< 193 × 103 mol/km2/yr) are lower than those from river chemistry. Regolith development in the Leizhou Peninsula may account for < 25 % of total chemical erosion, suggesting significant hidden erosion processes. These observations indicate that other potential weathering sources in aquifers and steeper terrains should be independently estimated when assessing basin-scale CO2 consumption.
KW - CO consumption
KW - Continental weathering
KW - Dust accretion
KW - Regolith production rates
KW - Uranium-series disequilibrium
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U2 - 10.1016/j.gloplacha.2024.104673
DO - 10.1016/j.gloplacha.2024.104673
M3 - Article
AN - SCOPUS:85212836668
SN - 0921-8181
VL - 245
JO - Global and Planetary Change
JF - Global and Planetary Change
M1 - 104673
ER -