Dear Perach Nuriel et al.,
I agree with both reviewers in their opinion that this is a very valuable contribution to the in situ U-Pb carbonate chronology and ms needs only some minor modifications. As I understand from your reply you found the comments and suggestions very valuable and are willing to modify the ms accordingly. therefore I am looking forward to receiving the revised ms,
best wishes
Axel Gerdes

Dear Perach Nurial et al.,
many thanks for sending the revised ms. The modifications you did are in line with the reviewers suggesitons...
However, there is one thing which gots more confusing through the changes. It is the distinction between single and multi-collector ICPMS ... as you aim to discuss the point that ASH15 appears not to be a suitable RM for single-collector but for MC-ICP-MS... (section 4.5)
What is the basis of it? You mentioned before acquired single- and multi-collector data on ASH-15 in different labs and showed this in a figure, but not discussed differences of the data sets. Perhaps you can do it or don’t want to do?
However, other labs acquired reasonable single collector ASH15 data: Frankfurt lab published various papers (e.g. Scardia et al. 2019 QSR, Cruset et al. 2020 J Geol Soc London, and Marine Petrol Geol 120) in which we used ASH15 and yielded precise ages (+-2%), within the uncertainty of the published ASH15 data. The same applies to Guillong et al. 2020 (this Spec. volume) … within 2% (excess of variance). At least there is currently no proof that LA MC-ICPMS data is much better than LA SC-ICPMS data.
It becomes a bit more confusing the section 4.5. The text partly speaks of sector-field ICPMS instead of MC-ICPMS, elsewhere it seems that Sectorfeld = MC-ICPMS is used, and for single-collectors "including Q-ICPMS" is added. It seems that the authors did not want to commit themselves or have made some changes based on the reviewer's comments, but not applied this consistent throughout the text. So the unexperient reader still gets the impression that compared with MC-ICPMS, single collector is not suitable for ASH15 analyses. While experient reader might come to the conclusion that the authors are confused and want to make a statement towards MC-ICPMS..
The main controlling factor is simply sensitivity or better signal strength (=depending on concentration and spot size and instruments sensitivity). Sector-field (single- and multi-collector !!!) are more sensitive than quadropole ICP-MS. Multicollector ICPMS are usually more sensitive than single-collector SF-ICPMS. However, if you consider older generation of MC-ICPMS and the MC-ICPMS from one company compared to that from another company (Neptune higher sensitivity than Nu Plasma; Element XR > Attom) , it stays true only in relative terms. The same applies to the older Element2 versus the ElementXR with Jet-interface.
So I would suggest that you change the text in section 4.5, and use instead a term like (line 424) less-sensitive ICP-MS (e.g. most quadrupole ICP-MS) and more-sensitive ICPMS (e.g. new generation of single and multi-collector ICPMS) for text line 427. And “Finally the JT …. can be used for most single- and multi-collector sector-field ICPMS instrument as well as the newer generation of quadrupole ICPMS.
- Please check the text again for typos/spelling, I found 3 times “avilable” (line 288, 307, 319).
- Fig 4b (BGC) What stands this for BGS? Please change and explain it in the text.
- Line 330 primary MS ??? you mean primary RM
- you consistent single-collector and multi-collector... in the text you write as well single collector ICP
Best wishes Axel Gerdes

Dear Perach, thanks for the quick repsonce... everything fine with me,
Axel

Dear authors
thanks for revising your manuscript following the review suggestions. The paper is now acceptable for publication and I will pass it on to production.
When you receive the proofs, please take some time and check the manuscript to make sure all is as flawless as can be.
Thanks for submitting your work to GEOCHRONOLOGY.
Kind regards
KLaus Mezger