The revised manuscript is much improved and in general the reviewer comments were adequately taken into account. Besides minor editorial suggestions (see bellow) I suggest that the authors clarify one important point in the abstract/introduction/conclusion. Much of the discussion of the implications of the authors’ findings depends upon how one defines “source region”. This is especially important when discussing the temporal variations observed in very large catchments (Garcon et al., 2013 and Lupker et al., 2013), which primarily reflect variations in the sourcing of the sediment within the catchment, not really temporal variations of the composition of the “source regions”. Overall I think it would be better to frame this discussion in the context of lithological units, as opposed to source regions, as these are actually controlling the Nd and Sr isotopic compositions. It would also be good to explicitly mention the key role played by crustal recycling processes in setting the composition of the different lithological units (see Delinger et al., EPSL 2015), as this is very nicely illustrated here for Sr and Nd isotopes.

Specific comments (page and line number refer to the “track change” version of the manuscript):

The last sentence of the abstract should be rewritten: seasonal variations of the composition of river sediments are old news and generalizing from this rather local study seems a bit of a reach.

P5 L30: delete “were”

P6 L1: Neodymium isotope ratios are …

P6 L26: there is a large range (the statement remains true no matter how long ago the measurements were made)

P7 L3: It has been observed that in a …

P9 L23: in “burying the lower down Frysajodden Formation”, “down” seems misplaced

P9 L24: which conveys sediment from the head to the toe of the glacier

Figure 2: the caption incorrectly states that the catchment boundary is a red dashed line (it is in fact a red solid line).

Dear authors,

Having looked at your revised manuscript in the context of the reviews and the AE report, I'm pleased to confirm acceptance of this paper in its current form. Thanks for choosing Esurf for this work, and I look forward to seeing the final paper published.

You will be asked to upload a final version of your manuscript prior to typesetting and review of the proofs. When you upload that version, you may want to consider the minor editing comments I noted below during my reading. However I leave these to your discretion.

Also, looking at your figures, I wonder if the font size might be too small on several of the figures (including Figs. 1 and 2). All text should be readable in print by those without exceptional eyesight. I want to encourage you to print the figures and make sure they are easily readable at the size you anticipate them appearing in publication (and please double-check that they come out at the right size during proof-reading). If you want to increase to font size, this will be easiest to do prior to typesetting.

Here are the few minor editing comments:

Page 6, Line 15 — varies would be more consistent with the tense elsewhere in this section

Page 7, Line 28 — I think this should say has, not have

Page 11, Lines 8-10 — This is a very long sentence and is somewhat confusing; it might help to break it up.

Page 11, Line 14 — no comma after I/S

Page 11, Lines 17-18 — check the phrasing here; again this is a bit confusing

Page 11, Line 24 — no comma after fish

Page 12, Line 5 — specify 1.3 epsilon units

Page 13, Lines 2-4 — I think the structure of this sentence could be cleaned up a little

Page 13, Line 14 — no comma after periods

Finally, it looks to me like the color scheme varies between figures, sometimes when referring to what I think are the same samples. This might be worth checking and making consistent if there are some differences.

Thanks again for submitting your work to Esurf.