About the Origin of Carbonado

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors, I would like to congratulate you on your interesting manuscript.   I found the text very interesting, however, I highlighted different aspects such as much for the information on vaguely described instrument parks and locations of the samples.   Some of the statements about the origin of carbonado can also be extended but the linkage with the shungite and tectonics can also extended, maybe you can also discuss the onset of the plate tectonics and the linkage with the carbon cycle within the early earth.   I added my specific comments to the pdf, you can track and correct them.

 

Comments for author File: Comments.pdf

Comments on the Quality of English Language

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Author Response

Dear Reviewer, thank you for your review. It really helps to improve the article. I will try to respond to your comments.

Line 55.  Correct "avachites." Corrected.

Line 101. Corrected.

Line 115. Corrected.

Line 119. Added information.

"The specimens were donated to us by a Brazilian colleague in 2013, their exact location within Brazil is not known.".

Line 126. Added information.

" at MQ University, Australia, in 2014."

Line 133. Corrected.

Line 136. Added the information.

"at the Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences."

Line 138. Added information.

"at the Institute of Geology and Mineralogy of the Siberian Branch of the Russian Academy of Sciences"

Line 162. Added information.

"(collection of the Institute of Geology and Mineralogy of the Siberian Branch of the Russian Academy of Sciences)"

Line 293. Added information.

"The size of this body can be judged from the gigantic area of distribution of carbonados in Africa and Latin America."

Line 301. Agreed. Corrected.

"we hypothesize that these diamonds have the longest exogenous history among the diamonds of the Siberian Platform."

Line 306. Corrected.

These facts, as well as the whole complex of the studied properties of carbonado, give us the opportunity to assume that the most real material for the formation of carbonado served as shungite rocks, immersed in the process of subduction to a great depth in the stability field of diamond and then exhumed to the surface of the Earth.

Line 326. Corrected.

"similar to the shungite field in Karelia".

Line 328. Supplemented.

"probably paleoproterozoic".

Line 419. Added.

"(monocellular algae)" "on the bottom of ocean basins."

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

There are several comments and questions for the authors regarding the manuscript.

Section 2. Materials and Methods

Lines 122-123 “The surface of the samples was cleaned in an autoclave…” The parameters (temperature, pressure, solutions, etc.) under which the surface of the samples was cleaned should be added.

Line 128 “…in high vacuum mode on carbon-coated samples.” What is the reason for the need to coat carbon samples with carbon? What is the thickness of the carbon coating in this case?

Section 3. Results

Figure 2 f. Most likely the scale is incorrect. Since this image shows the image of figure 2 e at a higher magnification, and the latter shows the same scale. Authors, check the correctness of the scale rulers on figure 2.

Lines 168-169 “On the pore walls after the removal of minerals the tops of octahedral diamond crystals in the size of the first microns are visible (Figure 2).” Not only the octahedral tops became visible, but to a greater extent the octahedral faces became visible (the size of the faces can be indicated, since it is not entirely clear how the authors measured the size of the tops).

Lines 174-175 “By the EBSD method it was found that crystallites on the surface of the polished plate …” Previously, there was no information in the description of the samples that any sample was previously polished. It should also be indicated whether the polished sample is the same as the one that was cleaned in an autoclave or not.

Lines 181-182 @Some grains show signs of plastic deformation in the form of fragmentation into sub- 181 grains with maximum angles of disorientation up to 7°” This statement would be good to be accompanied by a corresponding image (for example, to figure 2 b).

Figure 4. The axes are not labeled. The red line described in the text is not visible.

Line 186-188. What is the red line? Add references to theoretical diffractogram of diamond and the reference value of unit cell parameter 3.567A.

Lines 195-198. Information on cleaning samples with acids should be included in Section 2. Materials and Methods .

”Figure 5 shows the unit-normalized low-temperature PL spectra measured at excita- 195 tion wavelengths of 351 nm (1”    and 1 a).

What is the difference between obtaining spectra 1 and 1a? If there are differences, this must be indicated in Section 2. Materials and Methods. If 1a is an enlarged image of spectrum 1, this must be indicated in the caption to Figure 5.

Figure 5. Add "intensity" to the ordinate caption. It should be “PL intensity, a.u.”

Table 1. The columns Center title and Center structure of line 1 are not filled in.

line 226. Is the temperature level 1500-1600 °C really low temperature annealing?

Figure 6. Add "intensity" to the ordinate caption. It should be “Signal EPR intensity, a.u.”. On figure 6b remove “Y)” in the end of the ordinate caption.

Lines 253 and 281. “…2*10³...” and “…DMs=1 …”Check the spelling of the cubic power and number 1. Why is they highlighted in red in the text?

General remark to the Introduction and Discussion sections. Authors often refer to the general "...in the literature..." in the text without specifying specific references. It is better to confirm such statements with references of the corresponding articles.

 

Author Response

Dear Reviewer, thank you for your review. It really helps to improve the article. Please find the authors' point to point reply in attachment

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

I have read your manuscript "About the origin of Carbonado" from Minerals. It's properly written, well organized paper presented original studding of carbonado samples. The list of carbonado mineral inclusions is practically complete but it could be added by the nitride minerals inclusions  (Jones et al. ,2003. Eighth International Kimberlite Conference Abstracts, Victoria, Canada, p. A95.). On my opinion there is also not enough of arguments that the initial source of carbonado was shungites.  (It's known that nanodiamonds was detected in shungites that could be additional arguments about their connection).

 

Author Response

Dear Reviewer, thank you for your review. It really helps to improve the article. Please find the authors' point to point reply in attachment.

Author Response File: Author Response.pdf