General comment

My compliments. This is a well written article. The authors took all possible scenarios, factors and variations into consideration and explained everything accordingly.

Technical corrections

Line 566= Banden = Banded

Line 733= palce= place

Review of A numerical model for duricrust formation by laterisation by Fenske et al.

This manuscript presents a new numerical model, developed to explore duricrust formation through in-situ laterization in concert with regolith formation and landscape evolution. The paper clearly outlines the details and the rationale behind the model and presents an extensive suite of modeling experiments to explore the model in detail. Overall, this is a well-written and well-illustrated manuscript.

This development of a new numerical tools to simulate duricrust formation under different assumptions and in concert with landscape evolution, represents a solid scientific contribution to our understanding of duricrust formation and their influence on topographic steady-state and long-term landscape evolution. Particularly in combination with the previous work of the authors (Fenske et al., 2025), I believe this paper will be of interest to the wider geomorphological community. Future work will allow the model to be applied to specific sites with observations.

In some cases, for instance in the transient model simulations, I would have found it useful with a more direct comparison with a scenario without hardening (e.g., fig. 11), to understand how the topographic evolution is different when introducing laterization and duricrust formation/hardening. This could simply be exemplified with curves of the transient evolution e.g. of the hilltop with and without the various components of the LAT model (e.g., excluding the hardening feedback on erosion and/or mass loss).

Although the approach is fitting, the introduction to the computation of ages in section 3.2 could be clearer (lines 484-486 could be moved to section 3.2). Perhaps the section could also benefit from an illustrative figure showcasing an example; illustrating also what a PDF mean age represents compared to the chosen threshold hardening value (i.e., when something is defined as duricrust in the model) that may be reached at a different time than the mean from the PDF of ages (which would be fine).

More specific comments:

• Is section 1.6 really needed, or could it be included in section 1.2 or elsewhere?
• Figure 2. I am confused about the red arrows in b linked to ‘mineral transport’. There is no transport of minerals within the bedrock as I understand, but advection of fresh material with the uplift. This could simply be mentioned in the text (as it already is). If keeping the arrows, they should have the same length/velocity as the uplift arrows.
• Line 144: I would suggest ‘in the subsurface’.
• Figure 3 caption. I assume the brick red line represents the surface topography and not the rate.
• Lines 202-206: perhaps you want to motivate more explicitly here already (or earlier) why you explain the details of this other model (you do it later, lines 212-214).
• Line 215. ‘introducing a second hardening equation’; this may be misunderstood as if the first one is also in the model implementation. Consider using ‘an alternative hardening equation’.
• Equation 7 vs. 8; what is the reason for introducing the alternative nomenclature dy’ ?
• Line 300: ‘the ages are produces’, perhaps consider formulating this as the production of the elements that can be dated.
• Line 367 and elsewhere, would it be more appropriate to use K_D0 instead of K_D, according to equation 9? Also in line 390, you use K_d (small d)
• Line 395. This is the first time surface sedimentation is mentioned. I would recommend mentioning this already when the model is presented, that your model includes sedimentation in addition to surface erosion. This was not clear until this point.
• Lines 408-410: repetition, consider leaving out.
• Equation 17, should the precipitation fraction not be the other way around, to be consistent with equations 15 and 16?
• Figure, 15, 16, and 17, etc. The gray regions as well as the uplift rate dashed line in the right two panels are difficult to read, in terms of the relation to depth/distance axes. Perhaps add a more explanation or additional axis on the panels. In addition, the white lines on the left panels are not mentioned in the caption.
• Line 567: using ‘utilizing the duricrust formation model in concert with data’ instead of ‘implementing […]’ may be more appropriate here
• Line 660-661: what is relatively well constrained?
• Given the points in the discussion related to steady state (or not), I find it would be useful if it was more explicitly mentioned whether a certain presented model is in steady state or not.
• Lines 674-678: this does not seem to help to distinguish between the two formation mechanisms as said in the beginning of the paragraph. Perhaps elaborate further or clarify. The wording ‘strongly suggest that the duricrusts formed by WTF’ is in strong contrast with the following sentence.
• Line 702: the use of burial here is confusing, if there is no sedimentation. Is it simply lowering relative to base level? If there is mass loss throughout the column, I assume a given part of a vertical profile is getting closer to the surface while the surface is lowered?.
• Line 706-707: consider adding a few additional sentences on how isotopic composition could be used to distinguish between professes of formation.   
• Lines 750-754: consider moving these lines to section 5.6.