Many thanks for your positive take on our manuscript, we very much appreciate that the microscopic textures and our interpretation found your interest!

Thanks a lot for pointing out where our text was difficult to read, and for the minor revisions you suggested. We changed the text throughout according to the editorial suggestions given.

Specifically, we made the following changes:

Line 44: We referred to Noffke and Awramik, 2026 where suggested, thanks for pointing out to us this new and relevant publication.

Line 64: We referred to Zhu and Dittrich, 2016 and Reid et al., 2024 as it was suggested to add more from list in Noffke and Awramik, 2026.

Line 90: We followed suggestion to geographically specify the examples given.

Line 124: We followed suggestion to reformulate the last sentence of the introduction to more clearly state the objective of the MS.

Regarding your comment on the Study Area section already presenting some results that should be moved into the Results section: Thank you for this comment. This part in Study Area and Material describes the IODP 389 cores studied. As this has been previously published by Webster et al., 2025 (Expedition 389 Proceedings) and is not the result of our present study, we decided to keep this information in the Study Area and Material as otherwise we would have to cite the Webster et al., 2025 study in the Results part.

Thank you also for pointing out that the illustrations appeared to many and difficult to navigate. We followed the suggestion and reduced the SEM imagery. We also reorganized the figures a bit. We now indicate that Figure 5 is the overview and refer to the individual layers in Figure 5 at the beginning of the descriptions while referring to Figure 6 and 7 for specific features in the description of the layers. However, we also would note that the lack of adequate illustration of microbial textures has led to confusion in the past, because verbal descriptions are usually not a sufficient representation.

Again many thanks for taking the time to review our work, your suggestions helped a lot to improve the manuscript.

We thank the reviewer for these very insightful comments on microbial mats and in particular the topic of EPS. We fully agree on the nature of EPS and that the wording “preserved EPS” was not precise. We meant to point to signatures that we interpreted as calcified EPS. Such structures show preserved volumes and shapes characteristic of EPS, and our interpretation was proposed based on imaging comparisons with the relevant literature (e.g., Dohlkanova et al., 2011). This is now better stated in the Abstract (where we added the term “calcified”) (Line 26) and similarly later in the text to avoid any confusion (e.g., Lines 233, 285, 291), and where the word “preserved” alone could be unclear (Line 501). We fully agree that biogeochemical analyses would be most useful to better understand these microbialites. However, the biogeochemical analysis was not the purpose of the current study, and we are convinced that our conclusions are valid based on the petrography. Nevertheless, together with collaborative partners in the next step will be analysing the samples in a separate organic-biogeochemical study, which would be beyond the scope of the present study. In addition, we note that the organic content in the microbialites is low. Py-GC-MS therefore is not feasible, and a more laborious extraction is required that will be the focus of separate future study. We have added the word petrological to the last sentence of the abstract to make clear the aims of the study.

You mention that microbial post-reef systems are frequently observed and represent an important process in the reef factory. We made sure to more clearly cite and acknowledge those studies in the revised version. You also mention the absence of geochemical and biogeochemical analyses for supporting the microbial nature of the crusts in the present study. Indeed, earlier studies on the Pleistocene reef microbialites recovered during IODP 310 (Tahiti) and IODP 325 (Great Barrier Reef) have revealed most interesting patterns of lipid biomarkers. For example, Heindel et al., (2009, 2010) that revealed the important role of sulphate reducing bacteria, but interestingly no indication of cyanobacteria – these authors hypothesized that cyanobacteria could have been the primary producers while only the mineralizing sulphate reducers left a signature in the microbialite; and similarly Braga et al., (2019). However, in those Tahiti and GBR reef microbialites, the morphological record of the microbes is poor compared to the reef microbialites recovered during IODP 389 (Hawaii). Indeed, the material from Hawaii offers a unique opportunity to bring these methods and findings together for an integrated model of microbialite formation. However, this is beyond the scope of this petrographic-morphological study but will be the goal of future work as described above.

Thank you for pointing out the relevance of stable isotopes and lipid chemical analyses such as Pyrolysis-GC-MS. The stable isotope values we have determined are in the range of other publications on marine microbialites (e.g. Fogret et al. 2024; Chemical Geology), however, we have decided to include those values in the upcoming study of lipid biomarkers, to there make better sense of them in terms of metabolic pathways.

Also thank you for pointing out Raman spectroscopy as a useful method to identify the mineralogy of the Mg silicates. We will definitely follow up on that approach in a furture study. For gaining a better understanding of the organic matter that we interpret as calcified EPS, Raman spectroscopy presumably will not be as helpful as one cannot gain detailed information on the chemical characteristics, and thus the origin, of the organic matter.

We very much appreciate your positive comment on the quality of the figures and the organization of the paper! Also again many thanks for pointing out additional approaches to gain a better understanding of the microbialites that we will include in our ongoing and future work on the material from IODP 389.