Geophysical Properties of Precambrian Igneous Rocks in the Gwanin Vanadiferous Titanomagnetite Deposit, Korea

Round 1

Reviewer 1 Report

The draft manuscript, entitled “Geophysical properties of Precambrian igneous rocks in the Gwanin vanadiferous titanomagnetite deposit, South Korea”, minerals-1359269, “written by  Seungwook Shin, Seong-Jun Cho1, Eui-Jun Kim and Jihyun Lee”, and Submitted to section: “Special Issue: Geological and Tectonic Evolution of the East Asian Collage: Precambrian and Mesozoic” has just been reviewed. As far as I can see, this study provides important data on the formation of vanadiferous titanomagnetite ore. Next, this study contains data that will fill an important gap, such as a stable supply chain of vanadium can represent one of the most critical issues in terms of national indus-32 trial growth. Because these materials are found in rare parts of the world. Therefore, the paper will satisfy an important curiosity.

On the other hand, to make the article more attractive, additional my comments and my expectations from the authors are follows;

1.) It is seen that the topic is certainly of interest. Geology, geochemistry, and chemical-mineralogical data of the deposit would provide useful information for the related scientific community.

2.) Title of the paper is suitable for the Special Issue of Minerals.

3.) The section Abstract of the draft manuscript is unfortunately NOT sufficient and NOT quite explanatory. I strongly recommend giving some concrete numerical values of the geophysical features of Precambrian igneous rocks.

4.) The references are a little weak. Previous studies and the consequent comparative discussion should be increased a little more.

5.) Finally, the study has been mineralogically approved by me, and I recommend the draft manuscript for publication after major revisions.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Review of Manuscript Number: minerals-1359269 Title: Geophysical properties of Precambrian igneous rocks in the Gwanin vanadiferous titanomagnetite deposit, South Korea (Shin et al.)

The manuscript entitled "Geophysical properties of Precambrian igneous rocks in the Gwanin vanadiferous titanomagnetite deposit" reports geophysical properties for resource exploration. This paper is significant to understand geophysical characteristics of the vanadiferous titanomagnetite deposit, Gwanin in Gyeonggi massif, South Korea. However, first of all, it is recommended to update and correct the geological description in 2.1 Geology. Please refer to recent age data and geological report.

The geophysical properties depend on the quantity of ore minerals, which is common sense. So, it is necessary to give meaning to why it appears to be different, as if explaining it with the mineral contents (vol. %) or assemblages. It needs to be comparing and matching the petrological and mineralogical characteristics of each rock type (for example, what kind of ore minerals are present? How may has volume % of magnetite, ilmenite, or titanomagnetite).

Furthermore, the discussion part is weak. How much is the possible depth for exploration using geophysical properties mentioned on manuscript? Especially, more details should be placed on how these data can help to understanding the mineral exploration. It is well written and easy to read, but needs to be careful in using singular and plural in English expressions.

And this manuscript is the technical report rather than research paper. So, I suggest a moderated revision before the manuscript is accepted for minerals. It should be clearly rewritten for the purpose and application of the study rather than simple comparison among each rock type. I suggest focusing on the report on the output status of the geophysical property of rock type in this deposit and report it in the form of a ‘technical report’ or ‘news’.

August 31, 2021 In addition, following are the comments on this MS: Comments: (Numbering below correspond to numbers in the pdf MS). Jurassic Myeongseong granite has recently been reported to Cretaceous (112 Ma SHRIMP U–Pb zircon; Hwang & Kim, 2007).

Fig. 1, please modified the legend. Ex) Add the relationship of each rock (intrusive, unconformity…etc.). Match the drilling hole markings on the legend and the geological map. The geologic times of Geumhaksan andesite and Dongmakgol tuff have exchanged.

Fig. 2, Rock samples a) to e) look the same, because they are uniformed cylindrical sample of low photo quality. It can be more helpful for comparison if you present a rock slab with a photomicrograph of each rock sample together, and describe the mineral assemblages.

Fig. 4, There is almost no difference in density between discovered ore and gabbro. Commonly, density of magnetite, ilmenite, and gabbro are 5.1–5.2, 4.3–4.6, and 2.7–3.5 g/cm3, respectively. And, what does discovered ore mean. What is the difference from underground ore?

Line # 63: Donmgkgol --> Dongmakgol. Line # 157, 158, 183, 190, 222, and 225: How was each percentage calculated? Please, check it out. Line # 260: add comma like (a) underground ore, (b) discovered ore, (c) gabbro,

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

I read your manuscript with great interest since it is crucial getting a precise characterization of subsurface rocks. Undoubtedly, having a reliable sample characterization will increase the chances of highlighting any presence of mineral deposits. The latter is especially true when the ore discovery has to rely on geophysical techniques which are employed to identify the presence of mineral deposits. So, in my opinion, this work is relevant as it presents the appropriate lab stages to get the suitable geophysical characterization for samples obtained from a geological area. Moreover, the work ends concluding with the most suitable geophysical techniques to be employed according to the geophysical characterization, which is the main goal of this type of study. Potential readers, especially those who deal with the exploration of essential commodities, will be pleased with the reading of this work that is well organized, properly written, and that goes to the point, which means that it avoids unnecessary statements or paragraphs.

 

So, I would suggest the paper to be considered for publishing.

 

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Additional revisions in the draft manuscript, made by the authors, are sufficient for publication of the paper.

Author Response

We appreciate your decision of publication. We were able to improve our draft by your great comments. We are glad for that you review our draft.

Reviewer 2 Report

This article simply compares among the physical results, and lacks application or discussion. Moreover, I previously suggested a comparison through the characteristics of constituent minerals and rock types, but the author did not implement it because it took a long time. The physical characteristics of rocks reflect the characteristics of their constituent minerals. So mineral assemblage is important input data for comparing the physical data. Therefore, this manuscript is the technical report rather than research paper. So, I suggest report it in the form of a ‘technical report’ or ‘news’. On the other hand, please improve the paper through adding the mineralogical and petrological studies.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx