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Reply to Comment on “A simple model for regolith formation by chemical weathering” by Braun et al. Contradictory concentrations and a tale of two velocities by Harman et al.
Author(s) -
Braun Jean,
Guillocheau François,
Robin Cecile
Publication year - 2017
Publication title -
journal of geophysical research: earth surface
Language(s) - English
Resource type - Journals
eISSN - 2169-9011
pISSN - 2169-9003
DOI - 10.1002/2017jf004271
Subject(s) - weathering , regolith , dissolution , thermodynamics , simple (philosophy) , front (military) , geology , mineralogy , chemistry , physics , geomorphology , philosophy , astrobiology , oceanography , epistemology
The apparent contradiction evidenced by Harman et al. is, in our opinion, a consequence of them assuming that the concentration of the solute is at equilibrium value C eq , an assumption that is not part of our model. We take this opportunity to more clearly demonstrate that under the assumptions the concentration of the solute is not at equilibrium, the rate of dissolution and consequently the rate of propagation of the weathering front are, to first order, proportional to the velocity of the fluid parallel to the weathering front and thus to the slope of the water table. The results we derive from this assumption are therefore valid.