Review Reports - Fluid Properties and Genesis of Dolomites in the Devonian Guanwushan Formation of Upper Yangtze Platform, SW China

Round 1

Reviewer 1 Report

Title: Fluid Properties and Genesis of Dolomites in the Devonian Guanwushan Formation of Upper Yangtze platform, SW China

In this paper, authors discuss the genesis of dolomites at Guanwushan formation, Yangtze platform, SW China. This work provide good data set combining field, petrography, cathodoluminescence (CL), X-ray diffraction analysis, whole-rock elemental analysis, and carbon, oxygen and strontium isotope compositions. This data is important in terms of understanding paleoenvironmental conditions existed during dolomite genesis.

The paper is neatly written without much mistakes. I appreciate the authors and recommend the work for publication after minor revisions.

My main comment to consider during revision is about the interpretation of the results. As the authors claim, Line 42: "Among all the factors affecting dolomitization, salinity and temperature are the most important". Though large amount of different dataset are produced, nothing regarding these important factors are mentioned in the manuscript.

Figure 8 needs to be improved. The figure caption needs to be elaborated to discuss the meaning of this cartoon.

Discussion Section 5.3 is not providing any information regarding paleo-environmental conditions. Please expand this section.

Please also note that no CL images are provided.

All figure captions should be improved with more details.

Author Response

An: This sentence tried to express the significance of salinity and temperature in the role of dolomitization, but our study did not involve relevant content, and this sentence does not affect the expressions of context, so it was deleted.

Figure 8 needs to be improved. The figure caption needs to be elaborated to discuss the meaning of this cartoon.

An: The relevant sentences about this figure were added to the caption to describe the figure.

Discussion Section 5.3 is not providing any information regarding paleo-environmental conditions. Please expand this section.

An: Thanks for your comments, after consideration, we thought this part is not consistent with the objective of the paper, and it is useless to provide useful information, so this part is deleted.

Please also note that no CL images are provided.

An: The CL images were provided as the new Fig. 3.

All figure captions should be improved with more details.

An: Done.

Reviewer 2 Report

Dear Authors:

Thank you for this interesting study that should be a helpful contribution to the field. Unfortunately, I respectfully suggest that the manuscript is not of publication quality in its current form due to numerous problems including: explanation and calling out of figures/tables in the main text (this appears to be completely missed); unclear language that is often confusing and imprecise; and minor formatting errors. I have provided numerous comments and suggestions below for your consideration; please consider these non-exhaustive examples to apply throughout the manuscript--there is more that I did not comment on.

Abstract and elsewhere: Always define acronyms and abbreviations upon first use. Please define HREE and LREE in the abstract and “BSR” in the line 53.

Introduction: I strongly recommend that the authors provide a brief description of the dolomite classification they use early in the manuscript; they may use a description very similar to the one they provided much later in lines 146-148 (Results section).

Line 116: I believe that the authors mean to say that “Based on microscopic identification, 36 samples were selected for . . .”

Lines 116-135: Please include the sample amounts used in each of the analysis methods described this paragraph.

Lines 119-120: This is a confusing and generally unclear description of sample preparation. I believe I understand that the authors divided the initial samples into five parts each, if so please revise.

Lines 121-122: What does this mean? What “main element was tested?”

Line 126: Please elaborate on the acid digestion methodology.

Line 143: Incorrect capitalization of “results” in Section 4.

Line 162: What exactly is the meaning of “weak water energy?” Please clarify and also state its significance to fine-microcrystalline (FMD) dolomite.

Line 167: Please complete the following sentence, euhedral and subhedral what? “ . . . which is characterized by euhedral and subhedral.” Textures?

Line 172: Please be precise in your descriptions, change “this type of dolomite” to “FCD dolomite” (fine crystalline dolomite).

Line 177: Formatting problem. Correct format for “(3) Medium crystal dolomite (MCD)”

Lines 191-192: The writing is excessively choppy in this section. I recommend that these two sentences be combined into one smooth sentence.

Line 194: What is “it” referring to, please be more precise. “. . . which indicates that it is formed rapidly,”

Liens 215-217: Regarding “In contrast, in the lattice (00i) direction, CaCO3 and MgCO3 are completely randomly arranged, and the probability of finding Ca2+ ions, Mg2+ ions, and CO32- ions at any point in the crystal is the same. We define it as 0 in this case.” Perhaps I am missing something, but I am unclear on how it is possible for Ca-carbonate and Mg-carbonate to be “completely randomly arranged” in a lattice while simultaneously having “same” (equal) probability of finding calcium, magnesium and carbonate ions “at any point in the crystal.” Doesn’t random arrangement of these carbonate units also indicated unequal or random probabilities of finding specific constituents (i.e., Ca, Mg, carbonate)?

Lien 221: Please revise the following text, it doesn’t seem to make sense: “the formation time and rate of dolomite.” Do the authors mean to say “rate of dolomitization” here?

Lines 226-228: The last sentence is trying to make an important but it confusing and awkwardly written, please revise starting with at least the following revision: “Therefore, the older the formation, the deeper it is buried and, therefore, the stronger the effect of . . .”

Lines 229-233: There are several confusing items in this text: the authors use the words “average” and “standard” in the same context and seem to suggest the same meaning, how is this possible; the last sentence in this paragraph ends with “. . . increases accordingly” but what does this mean, increases accordingly with what or to what?

Author Response

An: The article has been polished by professional institution.

Abstract and elsewhere: Always define acronyms and abbreviations upon first use. Please define HREE and LREE in the abstract and “BSR” in the line 53.

An: Done.

An: Done.(in the Abstract)

Line 116: I believe that the authors mean to say that “Based on microscopic identification, 36 samples were selected for . . .”

An: Done.

Lines 116-135: Please include the sample amounts used in each of the analysis methods described this paragraph.

An: Done in Section 3.

An: Yeah, it means “divided the initial samples into five parts”.

Lines 121-122: What does this mean? What “main element was tested?”

An: Sorry for the mistake, it should be ‘major element’.

Line 126: Please elaborate on the acid digestion methodology.

An: Done in Section 3.

Line 143: Incorrect capitalization of “results” in Section 4.

An: Done.

Line 162: What exactly is the meaning of “weak water energy?” Please clarify and also state its significance to fine-microcrystalline (FMD) dolomite.

An: Done，it means that the energy of water body is weak.

Line 167: Please complete the following sentence, euhedral and subhedral what? “ . . . which is characterized by euhedral and subhedral.” Textures?

An: Yeah, it should be “euhedral and subhedral textures”.

Line 172: Please be precise in your descriptions, change “this type of dolomite” to “FCD dolomite” (fine crystalline dolomite).

An: Done.

Line 177: Formatting problem. Correct format for “(3) Medium crystal dolomite (MCD)”

An: Done.

Lines 191-192: The writing is excessively choppy in this section. I recommend that these two sentences be combined into one smooth sentence.

An: Done, two sentences revised to ‘The dolomite fillings are mainly saddle dolomites (SD), mainly developed in intercrystal-line pores (karst caves) and cracks.’

Line 194: What is “it” referring to, please be more precise. “. . . which indicates that it is formed rapidly,”

An: Done, ‘it’ should be “saddle dolomites (SD)”.

An: It means that the calcium, magnesium and carbonate ions arrange completely out of order.

Lien 221: Please revise the following text, it doesn’t seem to make sense: “the formation time and rate of dolomite.” Do the authors mean to say “rate of dolomitization” here?

An: Done, ‘it’ should be “rate of dolomitization”.

An: Done

An: It means the average value of FMD < FCD < MCD.

Reviewer 3 Report

Dear Authors,

Attached you find the file for comments

Comments for author File: Comments.zip

Author Response

This is an interesting paper to read and from my point of view it has many weaknesses that should be addressed before the paper can be published. However, the manuscript is not ready for publication yet required major revisions. Also, there are extensive grammatical issues and a general weakness in the written English.
Most of the comments are highlighted in yellow as seen manuscript text as attached file.
Below I give some additional comments listed with chapter name or line no.

An: The article has been polished by professional institution.

Abstract
Line 20-25 must be re-written according to REE results and patterns.

An: By calculating that these values of Ce anomalies and Eu anomalies are less than 1.
Introduction
No comments
Materials and methods
This chapter is OK
Results
Petrological and Mineralogical characteristics of dolomite
The Petrology is one of the core conclusions of the paper, but very poorly written and petrographic images also not clear. which must be re-written after my comments above have been addressed.

An: It has been re-written.
The degree of dolomites
Line 210-219 must be re-written

An: It has been re-written.
Geochemical characteristics of dolomite
Trace Elements
The Authors explain the detailed geochemical work in the Materials and methods chapter, but they should show Tables of the main and trace elements i9n addition to trace element ratios such as Mn/Sr for three types of dolomites

An: They have been added in the table 1.
Rare Earth Elements
In the line 283 the authors say that REE content relatively high, while in the lines 302-303 they say the total REE is relatively high. The author is presenting contrasting information.
Isotopes C, O and Sr isotopes is not my core expertise, a reviewer with expertise in isotopes may comments on this though.

An: The total content of REE is relatively low with the content less than limestone, we revised the words in Line 301-302.
Discussion and conclusions
This chapter is OK apart must be re-written when the comments above are addressed. The same apply to conclusions.

An: Discussion and conclusions were revised according to the comments.
Figures and Tables
The manuscript text should support by figures and tables, it must mention them in the body text.
Most of Figures are not mentioned by authors in the body text, except Figures 1 and 10.9

An: All figures has been quoted in the text.

Round 2

Reviewer 2 Report

The revised manuscript is much, much better--thank you. I respectfully suggest that the authors please go through and re-check the entire manuscript for grammar, formatting, and (very importantly) consistency and logical of interpretation on results.