the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 31 Jul 2023
Geochemical characterisation and protolith restoration of metamorphic rocks at Lazishao graphite mine, Sichuan
Abstract. This study determined the deposit characteristics and geochemical features of metamorphic rocks from the Lazishao graphite deposit in order to reconstruct the metamorphic protoliths and palaeo-sedimentary environment. The results show that the SiO2 content of the metamorphic rocks is high (55.60 % to 77.94 %), while Na2O is 0.22 % to 1.85 %, K2O is 1.87 % to 3.45 %, K2O > Na2O, and K2O/Na2O + K2O > 0.5. The fractionation degree of light rare earth elements (LREEs) is greater than that of heavy rare earth elements (HREEs), with LREE/HREE ratios of 3.09 to 8.77; LaN/YbN is 2.72 to 10.75, with a mean value of 9.69. The rocks have moderate negative Eu anomalies (δEu = 0.50 to 0.89, mean = 0.64). Ionic lithophile elements (e.g., Rb, Ba, and K) are relatively enriched, but Sr is relatively depleted. The graphite-bearing metamorphic rocks in the study area originated from sedimentary rocks, mainly mudstone and greywacke. The palaeo-sedimentary environment was a low-salinity terrestrial freshwater body in a cold or moderately cold climatic zone.
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Interactive discussion
Status: closed
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RC1: 'Comment on egusphere-2023-1528', Anonymous Referee #1, 30 Aug 2023
Review on the paper submitted to the Solid Earth by Wenqi Cheng, Haijun Yu, Xue Wang, Decai Kong, Bo Long "Geochemical characterisation and protolith restoration of metamorphic rocks at Lazishao graphite mine, Sichuan ".
General Comments
The manuscript presents detail petrographic description and geochemical data on major and trace elements of samples of sericite–quartz schist and two-mica–quartz schists from Lazishao graphite mine (Renhe District, Panzhihua City). The authors apply multiple discrimination diagrams to recreate the protolith of the graphite-bearing rocks, and conclude that organic-rich claystone and greywacke were deposited over a long period and then subjected to regional metamorphism during which organic carbon was recrystallized into graphite.
This English is generally good, only a few sentences need to be polished. However, I have several concerns, which are listed in the Specific Comments. Overall, the manuscript can be accepted for publication on Solid Earth, hence a medium revision is recommended.
Specific Comments
- The study is related toone of the huge ore-bearing formation of the graphite deposits. Please provide more detailed discussion on the geochemistry of thegraphite-bearing rocks in the formation, based on the results, implications and conclusions of other previous studies in the same area.
- The formatsof some reference need to be corrected.
Small annotation errors
Line 12, change “high” to “relatively higher”;
Line 25, change “desirable” to “remarkable”;
Line 94, change “directional” to “oriented”;
Line 97, change “interstitial between” to “interstitial to”;
Line 113, change “favourable” to “economically valuable”;
Line 122, change “Major elements compositions” to “Major element compositions”;
Line 154, change “μg/g” to “ppm”;
Line 159, “δC”, typo;
Line 217, change “apparent” to “evident”;
Table.1, please list the detection limit of each analytical method;
Tables.2-4, please note the significant digit of data;
Fig.1, the legend of Fig.1b is too small;
Fig.5, the labels are too small;
Fig.13, check the typos in labels.
Citation: https://doi.org/10.5194/egusphere-2023-1528-RC1 -
CC1: 'Reply on RC1', Haijun Yu, 26 Sep 2023
September 25(th), 2023
Solid Earth
Dear Reviewers,
We are very grateful to Reviewer for reviewing the paper so carefully.We have tried our best to improve and made some changes in the manuscript. These changes will make the paper is more reasonable.
Responds to the reviewers' comments:
Reviewer #1
Specific Comments
1.The study is related to one of the huge ore-bearing formation of the graphite deposits. Please provide more detailed discussion on the geochemistry of thegraphite-bearing rocks in the formation, based on the results, implications and conclusions of other previous studies in the same area.
Response：We value your feedback and suggestions , however, this is the first study of graphite deposits in this area.
2.The formats of some reference need to be corrected.
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Small annotation errors
Line 12, change “high” to “relatively higher”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 25, change “desirable” to “remarkable”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 94, change “directional” to “oriented”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 97, change “interstitial between” to “interstitial to”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 113, change “favourable” to “economically valuable”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 122, change “Major elements compositions” to “Major element compositions”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 154, change “μg/g” to “ppm”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 159, “δC”, typo;
Response：We are very sorry for our incorrect writing and it is rectified at Line.
Line 217, change “apparent” to “evident”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.1, the legend of Fig.1b is too small;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.5, the labels are too small;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.13, check the typos in labels.
Response：We are very sorry for our incorrect writing and it is rectified at Line.
Thank you for your consideration. I look forward to hearing from you.
Sincerely,
[Name] Haijun Yu
[Address] 66 Xiangshulin Road, Jinjiang District, Chengdu City, Sichuan Province, China
[Phone number] +8618109052790
[Email address] yuhaijun0601@163.com
-
AC1: 'Reply on CC1', Haijun Yu, 26 Sep 2023
September 25(th), 2023
Solid Earth
Dear Reviewers,
We are very grateful to Reviewer for reviewing the paper so carefully.We have tried our best to improve and made some changes in the manuscript. These changes will make the paper is more reasonable.
Responds to the reviewers' comments:
Reviewer #1
Specific Comments
1.The study is related to one of the huge ore-bearing formation of the graphite deposits. Please provide more detailed discussion on the geochemistry of thegraphite-bearing rocks in the formation, based on the results, implications and conclusions of other previous studies in the same area.
Response：We value your feedback and suggestions , however, this is the first study of graphite deposits in this area.
2.The formats of some reference need to be corrected.
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Small annotation errors
Line 12, change “high” to “relatively higher”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 25, change “desirable” to “remarkable”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 94, change “directional” to “oriented”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 97, change “interstitial between” to “interstitial to”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 113, change “favourable” to “economically valuable”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 122, change “Major elements compositions” to “Major element compositions”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 154, change “μg/g” to “ppm”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 159, “δC”, typo;
Response：We are very sorry for our incorrect writing and it is rectified at Line.
Line 217, change “apparent” to “evident”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.1, the legend of Fig.1b is too small;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.5, the labels are too small;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.13, check the typos in labels.
Response：We are very sorry for our incorrect writing and it is rectified at Line.
Thank you for your consideration. I look forward to hearing from you.
Sincerely,
[Name] Haijun Yu
[Address] 66 Xiangshulin Road, Jinjiang District, Chengdu City, Sichuan Province, China
[Phone number] +8618109052790
[Email address] yuhaijun0601@163.com
-
AC1: 'Reply on CC1', Haijun Yu, 26 Sep 2023
-
AC2: 'Reply on RC1', Haijun Yu, 23 Oct 2023
Dear referee and editor,
We thank you for your suggestions and corrections on the manuscript. We corrected the article following your review. Please find in the attachment our responses for each of your comments (in blue in the document).
Best regards
The authors
-
RC2: 'Comment on egusphere-2023-1528', Anonymous Referee #2, 07 Oct 2023
This work presents geochemical data for graphite bearing rocks to investigate their protolith, sedimentary environment, provenance and tectonic setting. It is of some interesting to a broad audience. However, the study is largely discriminant diagram based without much discussion and interpretation. Besides, although formation of graphite mine is considered as one of the important issues but is not referred later.
Some major points
The manuscript is generally well written, while there are still some grammar mistakes, typos and wrong expression. It is suggested to be edited carefully during the revision.
The motivation of this study is not as clearly stated in the introduction as it should be. The statement ‘ However, the microscopic characteristics, geochemistry, ore genesis, carbon source, and other deposit features of graphite mines in the region have not been thoroughly explored (lines 40-41) is too simple to evaluate the importance of the present study. At least, a brief introduction about what have been done, what kind of critical issues remaining unresolved and why this work can resolve them is necessary. More important, the issues raised in the introduction are not properly answered by this study
This study simply used some discriminant diagrams based on elemental data to interpret the protolith, sedimentary environment, provenance and tectonic setting for some graphite bearing rocks, while in-depth discussion is deficient. For instance, degree of fractionation between LREEs and HREEs was used to suggest sedimentary protoliths of the studied metamorphic rocks (line 156), while this conclusion is far from convincing.
There are two types of rocks, graphite ores and mica schist, studied. It is better to introduce, discuss and interpret them separately.
Some minor points
Line 12: SiO2 contents of the metamorphic rocks are high....
Line 16: Large ionic lithophile elements (LILE)
Line 23: delete the first sentence
Line 49: Yangtze Craton, please check it throughout the text
Line 66: have been destroyed, leaving only...
Line 101: what does the ‘fixed carbon’ mean?
Line 115: some more information about where and what is the drill holes maybe helpful
Line 122: for the elemental concentration, large LOI (up to 12) should be considered, especially when the elemental contents are used in the discussion.
Line 128: it will be helpful to explain a little bit more that why this value indicate sedimentary origin. In addition, what is normal sedimentary origin and is there abnormal sedimentary origin?
Line 143:what does the sedimentary differentation mean?
Line 156: why fractionated LREE and HREE indicates sedimentary protolith?
Line 186: Similarly, why?
Line 234: what does the ‘mixed greywacke’ mean?
Fig. 1 incorporate the Hainan and Taiwan islands into the insert figure in Fig. 1a
Figs2-4: combined them into one figure and some representative figures of mica schist are also necessary
Fig. 5 symbols are too small to be seen clearly
Fig. 13 explain how to calculated the ω values either in the text or in the figure caption. Besides, there is Chinese word in the lower left corner
Citation: https://doi.org/10.5194/egusphere-2023-1528-RC2 -
AC3: 'Reply on RC2', Haijun Yu, 23 Oct 2023
Dear referee and editor,
We thank you for your suggestions and corrections on the manuscript. We corrected the article following your review. Please find in the attachment our responses for each of your comments (in red in the document).
Best regards
The authors
-
AC3: 'Reply on RC2', Haijun Yu, 23 Oct 2023
Interactive discussion
Status: closed
-
RC1: 'Comment on egusphere-2023-1528', Anonymous Referee #1, 30 Aug 2023
Review on the paper submitted to the Solid Earth by Wenqi Cheng, Haijun Yu, Xue Wang, Decai Kong, Bo Long "Geochemical characterisation and protolith restoration of metamorphic rocks at Lazishao graphite mine, Sichuan ".
General Comments
The manuscript presents detail petrographic description and geochemical data on major and trace elements of samples of sericite–quartz schist and two-mica–quartz schists from Lazishao graphite mine (Renhe District, Panzhihua City). The authors apply multiple discrimination diagrams to recreate the protolith of the graphite-bearing rocks, and conclude that organic-rich claystone and greywacke were deposited over a long period and then subjected to regional metamorphism during which organic carbon was recrystallized into graphite.
This English is generally good, only a few sentences need to be polished. However, I have several concerns, which are listed in the Specific Comments. Overall, the manuscript can be accepted for publication on Solid Earth, hence a medium revision is recommended.
Specific Comments
- The study is related toone of the huge ore-bearing formation of the graphite deposits. Please provide more detailed discussion on the geochemistry of thegraphite-bearing rocks in the formation, based on the results, implications and conclusions of other previous studies in the same area.
- The formatsof some reference need to be corrected.
Small annotation errors
Line 12, change “high” to “relatively higher”;
Line 25, change “desirable” to “remarkable”;
Line 94, change “directional” to “oriented”;
Line 97, change “interstitial between” to “interstitial to”;
Line 113, change “favourable” to “economically valuable”;
Line 122, change “Major elements compositions” to “Major element compositions”;
Line 154, change “μg/g” to “ppm”;
Line 159, “δC”, typo;
Line 217, change “apparent” to “evident”;
Table.1, please list the detection limit of each analytical method;
Tables.2-4, please note the significant digit of data;
Fig.1, the legend of Fig.1b is too small;
Fig.5, the labels are too small;
Fig.13, check the typos in labels.
Citation: https://doi.org/10.5194/egusphere-2023-1528-RC1 -
CC1: 'Reply on RC1', Haijun Yu, 26 Sep 2023
September 25(th), 2023
Solid Earth
Dear Reviewers,
We are very grateful to Reviewer for reviewing the paper so carefully.We have tried our best to improve and made some changes in the manuscript. These changes will make the paper is more reasonable.
Responds to the reviewers' comments:
Reviewer #1
Specific Comments
1.The study is related to one of the huge ore-bearing formation of the graphite deposits. Please provide more detailed discussion on the geochemistry of thegraphite-bearing rocks in the formation, based on the results, implications and conclusions of other previous studies in the same area.
Response：We value your feedback and suggestions , however, this is the first study of graphite deposits in this area.
2.The formats of some reference need to be corrected.
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Small annotation errors
Line 12, change “high” to “relatively higher”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 25, change “desirable” to “remarkable”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 94, change “directional” to “oriented”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 97, change “interstitial between” to “interstitial to”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 113, change “favourable” to “economically valuable”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 122, change “Major elements compositions” to “Major element compositions”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 154, change “μg/g” to “ppm”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 159, “δC”, typo;
Response：We are very sorry for our incorrect writing and it is rectified at Line.
Line 217, change “apparent” to “evident”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.1, the legend of Fig.1b is too small;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.5, the labels are too small;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.13, check the typos in labels.
Response：We are very sorry for our incorrect writing and it is rectified at Line.
Thank you for your consideration. I look forward to hearing from you.
Sincerely,
[Name] Haijun Yu
[Address] 66 Xiangshulin Road, Jinjiang District, Chengdu City, Sichuan Province, China
[Phone number] +8618109052790
[Email address] yuhaijun0601@163.com
-
AC1: 'Reply on CC1', Haijun Yu, 26 Sep 2023
September 25(th), 2023
Solid Earth
Dear Reviewers,
We are very grateful to Reviewer for reviewing the paper so carefully.We have tried our best to improve and made some changes in the manuscript. These changes will make the paper is more reasonable.
Responds to the reviewers' comments:
Reviewer #1
Specific Comments
1.The study is related to one of the huge ore-bearing formation of the graphite deposits. Please provide more detailed discussion on the geochemistry of thegraphite-bearing rocks in the formation, based on the results, implications and conclusions of other previous studies in the same area.
Response：We value your feedback and suggestions , however, this is the first study of graphite deposits in this area.
2.The formats of some reference need to be corrected.
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Small annotation errors
Line 12, change “high” to “relatively higher”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 25, change “desirable” to “remarkable”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 94, change “directional” to “oriented”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 97, change “interstitial between” to “interstitial to”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 113, change “favourable” to “economically valuable”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 122, change “Major elements compositions” to “Major element compositions”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 154, change “μg/g” to “ppm”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Line 159, “δC”, typo;
Response：We are very sorry for our incorrect writing and it is rectified at Line.
Line 217, change “apparent” to “evident”;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.1, the legend of Fig.1b is too small;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.5, the labels are too small;
Response：We appreciate it very much for this good suggestion, and we have done it according to your ideas.
Fig.13, check the typos in labels.
Response：We are very sorry for our incorrect writing and it is rectified at Line.
Thank you for your consideration. I look forward to hearing from you.
Sincerely,
[Name] Haijun Yu
[Address] 66 Xiangshulin Road, Jinjiang District, Chengdu City, Sichuan Province, China
[Phone number] +8618109052790
[Email address] yuhaijun0601@163.com
-
AC1: 'Reply on CC1', Haijun Yu, 26 Sep 2023
-
AC2: 'Reply on RC1', Haijun Yu, 23 Oct 2023
Dear referee and editor,
We thank you for your suggestions and corrections on the manuscript. We corrected the article following your review. Please find in the attachment our responses for each of your comments (in blue in the document).
Best regards
The authors
-
RC2: 'Comment on egusphere-2023-1528', Anonymous Referee #2, 07 Oct 2023
This work presents geochemical data for graphite bearing rocks to investigate their protolith, sedimentary environment, provenance and tectonic setting. It is of some interesting to a broad audience. However, the study is largely discriminant diagram based without much discussion and interpretation. Besides, although formation of graphite mine is considered as one of the important issues but is not referred later.
Some major points
The manuscript is generally well written, while there are still some grammar mistakes, typos and wrong expression. It is suggested to be edited carefully during the revision.
The motivation of this study is not as clearly stated in the introduction as it should be. The statement ‘ However, the microscopic characteristics, geochemistry, ore genesis, carbon source, and other deposit features of graphite mines in the region have not been thoroughly explored (lines 40-41) is too simple to evaluate the importance of the present study. At least, a brief introduction about what have been done, what kind of critical issues remaining unresolved and why this work can resolve them is necessary. More important, the issues raised in the introduction are not properly answered by this study
This study simply used some discriminant diagrams based on elemental data to interpret the protolith, sedimentary environment, provenance and tectonic setting for some graphite bearing rocks, while in-depth discussion is deficient. For instance, degree of fractionation between LREEs and HREEs was used to suggest sedimentary protoliths of the studied metamorphic rocks (line 156), while this conclusion is far from convincing.
There are two types of rocks, graphite ores and mica schist, studied. It is better to introduce, discuss and interpret them separately.
Some minor points
Line 12: SiO2 contents of the metamorphic rocks are high....
Line 16: Large ionic lithophile elements (LILE)
Line 23: delete the first sentence
Line 49: Yangtze Craton, please check it throughout the text
Line 66: have been destroyed, leaving only...
Line 101: what does the ‘fixed carbon’ mean?
Line 115: some more information about where and what is the drill holes maybe helpful
Line 122: for the elemental concentration, large LOI (up to 12) should be considered, especially when the elemental contents are used in the discussion.
Line 128: it will be helpful to explain a little bit more that why this value indicate sedimentary origin. In addition, what is normal sedimentary origin and is there abnormal sedimentary origin?
Line 143:what does the sedimentary differentation mean?
Line 156: why fractionated LREE and HREE indicates sedimentary protolith?
Line 186: Similarly, why?
Line 234: what does the ‘mixed greywacke’ mean?
Fig. 1 incorporate the Hainan and Taiwan islands into the insert figure in Fig. 1a
Figs2-4: combined them into one figure and some representative figures of mica schist are also necessary
Fig. 5 symbols are too small to be seen clearly
Fig. 13 explain how to calculated the ω values either in the text or in the figure caption. Besides, there is Chinese word in the lower left corner
Citation: https://doi.org/10.5194/egusphere-2023-1528-RC2 -
AC3: 'Reply on RC2', Haijun Yu, 23 Oct 2023
Dear referee and editor,
We thank you for your suggestions and corrections on the manuscript. We corrected the article following your review. Please find in the attachment our responses for each of your comments (in red in the document).
Best regards
The authors
-
AC3: 'Reply on RC2', Haijun Yu, 23 Oct 2023
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