Gothic-Arch Calcite from Speleothems of the Bohemian Karst (Czech Republic): Its Occurrence, Microscopic Ultrastructure and Possible Mechanism of Growth

Round 1

Reviewer 1 Report

The manuscript is valuable to be published in MDpi Journal

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Author Response

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Reviewer 2 Report

Gothic-arch calcite from speleothems of the Bohemian Karst (Czech Republic): its occurrence, microscopic ultrastructure and possible mechanism of growth
Václav Suchý 1, Kateřina Pachnerová Brabcová 1, Jiří Zachariáš 3, Ivo Světlik 1 and Lenka Borecká 2

abstract: ok

1.inroduction
ok, the intentions to outline the genesis of the origin are emphasized, but the title of the article does not correspond to that, it is very descriptive :-(
I recommend adding a brief argument for the initial formation of caves during hypogenic fluid activity.

2. geological setting
Fig.2 on B and C it is not easy to see, a larger and more contrasting detail would fit faether-like calcite aggregates and gothic-arch calcite crystals

3. samples and methods

4.results
...apparently secondary silicification by opal and quartz that infilled pores leached in the calcite matrix of the speleothems (Figures 3C and D).  - not clear from the picture, the description in the pictures would be appropriate! it is not clear what the objects are.

chap.4.1. is confusing, it is difficult for the reader to orientate what is being said about which type (morphological ??), descriptions of macroscopic and microscopic features of some types of crystals intertwine with?
A system of studied crystals/shapes/forms should be created first, which is not and therefore it is confusing. Some categories are developed in chap.4.2., But how do they relate to the descriptions in chap.4.1?

Many descriptions contain very detailed information, including the mechanism of origin, which, however, is not substantiated by arguments, but these facts are difficult to prove. A crystallograph assessment/opinion would be appropriate.
(I would also recommend finding out the opinion of a microbiologist)

fig9E - more detailed view/immage would be very appropriate!

Chapter 4.3 - Fluid inclusions
it is necessary to divide the information on mineral (silica) inclusions and fluid inclusions - it can't all be in the chapter called "fluid inclusions" - it's misleading

other data and interpretations ok!

fig11B, C - it is necessary to mark trails and individual fluid inclusions

5. interpretation and discussion

Is there a difference in the composition of gothic-arch and dog-teeth calcite gothic-arch and dogtooth calcite crystals - what minor elements do they contain ??? - if so, they could be used as a comparison category of crystals, types of calcites .....

Also, some chemical minor components could participate (by release, displacement) in the later new crystallographic form. Unfortunately, we don't know !?

Arguments/discussions and descriptions of the formation of carbonate forms by microorganisms are repeated several times in the text.

------final conclusion
The documentation and descriptions are very detailed and the authors have done a lot of work to do this. It certainly has a significant contribution to make to the general understanding of the formation of such and various forms of carbonates in a given environment. Further research should involve experimental crystallography and the cultivation of carbonate crystals under different conditions in order to compare and obtain arguments for a more accurate determination of the conditions of formation.
The article is suitable for publication in Minerals.

Comments for author File: Comments.pdf

Author Response

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Reviewer 3 Report

Congratulations to the authors for this quality work. I have made some minor suggestions as seen in attached file.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf