See attached PDF.

Review of “DQPB: software for calculating disequilibrium U-Pb ages” by Pollard et al., submitted to Geochronology.

This review is by Ryan Ickert (Purdue University)

This manuscript briefly describes the functioning of a software package designed primarily to reduce U-Pb data from speleothems derived by ICP-MS, where the samples are young enough to require corrections for intermediate daughter products disequilibrium.  Overall, this is an excellent manuscript and is suitable for publication in Geochronology.  I was fortunate to be able to read the excellent comment by Pieter Vermeesch prior to writing this review.  I won’t repeat what he said, but I very much endorse his recommendation regarding the treatment of ²³⁴U.  The manuscript is written in a very clear and concise manner, the equations are suitable and written in a way that makes them relatively easy to follow, the examples are well-chosen, and the figures are well-drafted.  The references are particularly well chosen to isolate both early literature, significant work from the 80s and 90s, and appropriate works that highlight recent developments.  Having done a deep dive into some of this literature myself a few years ago, I appreciate the well-curated references.

Regarding the software itself, I think that the authors have struck a good balance between accessibility and availability to more programming-savvy users.  I applaud the use of Github and the use of a specific license allowing modification.



The following are some minor points, some of which the authors might consider in a revised manuscript.  I appreciate that generally authors are encouraged to respond to these reviews, but I don’t see any reason that they should necessarily do so in this case.  I encourage them instead to engage fully with the Vermeesch review.

Line 30:  The statement about zircon excluding Th implies to me that Th is incompatible in zircon (e.g., the mineral/melt partition coefficient is less than 1).  This is not correct.  Thorium is typically compatible in zircon, but simply less compatible than uranium, which leads to a deficit in ²³⁰Th relative to ²³⁸U, though an *overall* increase relative to a melt.

Line 62:  The password is “armpit”.

Line 164:  It might be useful to a reader, at this point, to guide them towards Schmitt (2007, American Mineralogist V92 p691-694) where Pa/U partitioning in zircon was directly constrained.  The rest of this manuscript is so comprehensive it would probably fit in nicely.



Figure 4:  The figure is not present in my copy of the manuscript, but I assume this is a typesetting error.

Line 287: This is an incredibly trivial point but I think that “adopted” is probably overstating the degree to which robust statistics have been used in geochronology.  The vast majority of data is treated with classical statistics – I would think that “proposed for” rather than “adopted in” is appropriate.