Characteristics and Mechanism of the Ore-Forming Fluids in the Shimensi Tungsten Polymetallic Deposit in Southeastern China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

From a professional point of view, the manuscript is at a good level. New data on ore forming fluids in the Shimensi tungsten polymetallic deposit in Southeastern China are presented. Appropriate methods were chosen for the study and the work is well structured.

I have only a few comments on the formal side of the article: 

- The quality of Figure 5 is poor. Unable to read the scale. I recommend to improve it.

- There are many typos in the manuscript, it must be checked. Some corrections are listed in the attached pdf.

- Some sentences do not make much sense, it would be appropriate to reformulate them. 

 

 

     

Comments for author File: Comments.pdf

Author Response

From a professional point of view, the manuscript is at a good level. New data on ore forming fluids in the Shimensi tungsten polymetallic deposit in Southeastern China are presented. Appropriate methods were chosen for the study and the work is well structured.

Thanks for your recognition of our work. Your suggestions have helped to significantly improve the manuscript. We will continue to work hard.

Q1: The quality of Figure 5 is poor. Unable to read the scale. I recommend to improve it.

We reworked Figure 5 to improve the quality of the figure, especially to make the scale more obvious. Please check it in the attachment for modification effect.

 

Q2: There are many typos in the manuscript, it must be checked. Some corrections are listed in the attached pdf.

We checked the manuscript for typos one by one and made corrections, with the corrections marked in red. Please check it in the attachment for modification effect.

 

Q3: Some sentences do not make much sense, it would be appropriate to reformulate them.

We made changes to some sentences that didn't make sense  and highlighted them in red. Please check it in the attachment for modification effect.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

In this manuscript, the author mainly studied the ore-forming fluids of Shimensi tungsten polymetallic deposit and explored its ore-forming mechanism and characteristics. There are three mineralization types of the deposit, which are veinlet-disseminated type, thick quartz vein type and hydrothermal crypto explosion breccia type. The fluid inclusions of the above three types of mineralization were discussed. By testing the temperature, density and salinity of the fluid inclusions, the ore-forming environment of low pressure, weak acidity and weak reductivity was determined. The H-O isotope geochemistry indicated that the ore-forming fluids were mainly derived from magmatic water and the addition of atmospheric precipitation.

However, there are still some mistakes and confusions in the manuscript. Therefore, I suggest the manuscript should be acceptance after a moderate revision, and hoping these comments will be helpful to the manuscript.

 

Sampling description

Whether the formation period of the selected samples is consistent. If the sample formation period is inconsistent, does it affect the discussion of mineralization mechanism? Please add more information.

 

H-O Isotopic characteristics

There is a classification method in the data description which is different from the previous and the following table, please correct or supplement it.

 

Ore-forming fluid system

 

The information you quote " the Na⁺/ K⁺ of magmatic hydrothermal fluids is generally less than 1, while the fluids from deeper genesiss containing higher F^-, Cl^- and larger F^-/Cl^-" is the exact opposite of the ratios in your sample below. How is it concluded that the ore-forming fluid has magmatic fluid characteristics? Please cite more references that support your point.

 

Detailed comments

1. Line 28-42, I suggest that these two paragraphs be condensed and merged into one.

2. Line 81, add the references.

3. Line 86, add the references.

4. Figure 2, add the references.

5. Figure 4, lack of scale.

6. Figure 5, please update the figure, the scale is not clear.

7. Line 242, wt8.81% à 8.81 wt.%. Suggest using this in the whole text.

8. Table 2, NaCleq (%) à NaCl_eq (wt.%)

9. Table 3, please add units.

10. Line 306 and 312, this part should be merged into previous section instead of here. I suggest that you can put this description in chapter 1 (Introduction).

11. Line 314, 357, 360, 378, 384, Shimenshi à Shimensi. Please check the full text.

12. Line 325, add the references.

13. Figure 9, add the references.

14. Line 333, genesiss à genesis

 

 

 

 

 

 

 

 

Author Response

Comments and Suggestions for Authors

 

In this manuscript, the author mainly studied the ore-forming fluids of Shimensi tungsten polymetallic deposit and explored its ore-forming mechanism and characteristics. There are three mineralization types of the deposit, which are veinlet-disseminated type, thick quartz vein type and hydrothermal crypto explosion breccia type. The fluid inclusions of the above three types of mineralization were discussed. By testing the temperature, density and salinity of the fluid inclusions, the ore-forming environment of low pressure, weak acidity and weak reductivity was determined. The H-O isotope geochemistry indicated that the ore-forming fluids were mainly derived from magmatic water and the addition of atmospheric precipitation.

However, there are still some mistakes and confusions in the manuscript. Therefore, I suggest the manuscript should be acceptance after a moderate revision, and hoping these comments will be helpful to the manuscript.

Thanks for your recognition of our work. Your suggestions have helped to significantly improve the manuscript. We will continue to work hard.

 

Sampling description

Whether the formation period of the selected samples is consistent. If the sample formation period is inconsistent, does it affect the discussion of mineralization mechanism? Please add more information.

Thanks for your suggestion. The Shimensi W mineralization occurred in the Early Cretaceous and is likely associated with the Mesozoic granites, especially porphyritic biotite and fine-grained granites. 

We added a sentence “The primary fluid inclusions in these samples are used to represent the ore forming-fluids in different mineralization stages in the Shimensi deposit.” 

 

H-O Isotopic characteristics

There is a classification method in the data description which is different from the previous and the following table, please correct or supplement it.

Thanks for your suggestion. We have reclassified the H-O isotope characteristics with reference to Table 2 and Table 4. More details are as follows:

The results of hydrogen and oxygen isotope analysis of quartz samples are shown in Table 4. The hydrogen isotope variation of quartz samples is small, ranging from -77.8‰ to -60.6‰ (average value -69.25‰).

The δD_V-SMOW values of veinlet-disseminated type ore bodies range from -69.3‰ to -64.2‰, with an average value of -66.93‰. The δ¹⁸O_V-SMOW of values of quartz range from 12.5‰ to 13.5‰, with an average value of 12.95%, and the calculated δ¹⁸O_H2O values range from 1.92‰ to 2.91‰, with an average value of 2.37%.

The δD_V-SMOW values of hydrothermal crypto-expolisive breccia-type ore bodies range from -68.6‰ to -60.6‰, with an average value of -64.45‰. The δ¹⁸O_V-SMOW of values of quartz range from 12.4‰ to 13.5‰, with an average value of 12.95%, and the calculated δ¹⁸O_H2O values range from 1.82‰ to 2.91‰, with an average value of 2.37%.

The δD_V-SMOW values of thick quartz vein-type ore bodies range from -77.8‰ to -66.7‰, with an average value of -71.85‰. The δ¹⁸O_V-SMOW of values of quartz range from 12.2‰ to 15.3‰, with an average value of 13.02%, and the calculated δ¹⁸O_H2O values range from 2.09‰ to 5.12‰, with an average value of 2.90%.

 

Ore-forming fluid system

The information you quote " the Na+/ K+ of magmatic hydrothermal fluids is generally less than 1, while the fluids from deeper genesiss containing higher F-, Cl- and larger F-/Cl-" is the exact opposite of the ratios in your sample below. How is it concluded that the ore-forming fluid has magmatic fluid characteristics? Please cite more references that support your point.

Thanks for your suggestion. We reviewed the references[13,14] and modified the article in line 351-352 marked in red.

Recent studies have shown that the granitic magma may be the source of the oreforming material[13-14]. According to the ion concentration characteristics of the fluid components, the Na⁺/K⁺ in the fluid inclusions within the deposit are all greater than 1, while the F^-/Cl^- are all less than 1. This is mainly due to the characteristics of the mineralizing fluid as a magmatic fluid, and with the mineralization proceeds, atmospheric precipitation enters a larger proportion of the fluid system[20]. The low F^- content in fluid inclusions within the Shimensi mine indicates that F does not play a dominant role in the mineralization process, or it is reduced due to the decrease of atmospheric precipitation.

 

Q1:Line 28-42, I suggest that these two paragraphs be condensed and merged into one.

Thanks for your suggestion. We merged these two paragraphs into one.

 

Q2: Line 81, add the references.

Thanks for your suggestion. We added the references[10] and marked it in red.

 

Q3:Line 86, add the references.

Thanks for your suggestion. We added the references[10] and marked it in red.

 

Q4:Figure 2, add the references.

Thanks for your suggestion. We added the references[25] and marked it in red.

 

Q5:Figure 4, lack of scale.

Thanks for your suggestion. We redrawed Figure 4 and added the scale.

 

Q6:Figure 5, please update the figure, the scale is not clear.

Thanks for your suggestion. We updated Figure 5 and made the scale clearer.

 

Q7:Line 242, wt8.81% à 8.81 wt.%. Suggest using this in the whole text.

Thanks for your suggestion. We changed wt8.81% to 8.81 wt.%. Then we checked and corrected all the errors of type one by one and marked it in red.

 

Q8: Table 2, NaCleq (%) à NaCleq (wt.%)

Thanks for your suggestion. We changed NaCleq (%) into NaCleq (wt.%) in Table 2 and marked it in red.

 

Q9:Table 3, please add units.

Thanks for your suggestion. We added the units in Table 3 and marked it in red.

 

Q10:Line 306 and 312, this part should be merged into previous section instead of here. I suggest that you can put this description in chapter 1 (Introduction).

Thanks for your suggestion. We modified some sentences and put this description in chapter 1(Introduction). We marked this description in red.

 

Q11:Line 314, 357, 360, 378, 384, Shimenshi à Shimensi. Please check the full text.

Thanks for your suggestion. We checked the full text and changed all the “Shimenshi” into “Shimensi”. Then we marked these typos in red.

 

Q12: Line 325, add the references.

Thanks for your suggestion. We added the references[20] and marked it in red.

 

Q13:Figure 9, add the references.

Thanks for your suggestion. We added the references[24] and marked it in red.

 

Q14: Line 333, genesiss à genesis

Thanks for your suggestion. We checked the full text and changed “genesiss” into “genesis”. Then we marked it in red.

Author Response File: Author Response.docx