Induced Polarization as a Tool to Assess Mineral Deposits: A Review

Round 1

Reviewer 1 Report

This paper is judged to be a paper that reviewed the basic theory, especially for the polarization phenomena and the applicability of the induced polarization (IP) exploration technique to the field of mineral exploration. Unlike other review papers published before, the authors paid special attention to the mathematical formulation of IP effects that occurred in the minerals, compared and verified its results with those obtained through laboratory experiments, and explained how mineral particles affect IP measurements. And several field cases are also presented to illustrate its usefulness. The factors that cause the IP phenomenon vary greatly from case to case and are complicated. So it is generally recognized that it is nearly impossible to explain all the real phenomena with a single mathematical model. Nevertheless, the theories reviewed in this paper which are based on some special assumptions could give the researcher who is interested in the IP method a useful insight concerning the interpretation of IP data. Eventually, it will be of great help in applying it to real data.

The overall contents, composition, and explanation are considered appropriate. However, there seem to be some parts that need additional explanation or modification in the content. if you supplement the relevant information a little more, it will help the interested reader to understand the usefulness of the IP method.

I have summarized some comments as follows. I hope I would help you revise your paper

1. It would be better if you add more explanation about the IP method in the frequency domain. Comparing the explanation of the time domain IP method, that of the frequency domain IP method seems to be too simplified or omitted in your paper. Although the term complex conductivity (resistivity) is greatly used in the explanation of the mathematical model and IP characteristic of a material, its detailed explanation is not found in this paper.

2. If possible, summarize the conclusions you draw in each chapter and then show them in a table. I think it will be helpful to the reader to understand the relationship between IP phenomena and the factors that cause IP effects.

3. The format of some references is slightly different from others. Please check and modify the formats of these references. And there are many missing references in this paper. Please add appropriate references for them.

Other minor corrections requests are summarized as follows.

62-63: Flekkoy et al., 2013 à reference missing

119-120: Usually, the measurements are done in the time domain in the field or in the frequency domain in the laboratory. à In recent years, frequency domain exploration has been carried out a lot in the field, and the results have been published. This sentence is likely to lead to a misunderstanding that frequency-domain measurements are conducted only in laboratories. It’s better to comment that the use of frequency-domain IP measurement is conducted in the field these days.

165: i.e. Direct Current DC condition -> Direct Current (DC) condition

232: De Witt, 1979 - reference missing.

244: Abdulsamad et al.2017 - Abdulsamad et al., 2017 (insert comma)

270: Wong, 1981 - check the year of reference. (1979 ?)

345-346: But depends on the concentration of the charge… - incomplete sentence.

349: Abdulsamad et al.2017 - Abdulsamad et al., 2017 (insert comma)

363: Sen et al., 1981n  - remove “n”

474: grain size size  .--> remove repeated word “size”

560: Siegel (1959) - Seigel (1959)

605: equations 16 and 17 - equation (59) and (60)

634-637: Please add the mathematical definition of normalized chargeability and quadrature conductivity. The definition of normalized chargeability appears in the figure caption in Fig. 31. The term normalized chargeability and quadrature conductivity appear suddenly in this paragraph.

745-745: SSIP (spread spectrum induced polarization) - Abbreviation and original sentences are used together. After the initial definition, it would be better to use SSIP terminology only.

755: VMS (Volcanogenic massive sulfide) - please, add the definition of VMS.

776: Zondres2D - ZondRes2D

792: SMS (seafloor massive sulfides) - I think it would be better to unify the terms afterward.

806: Kasaya et al (2019) – check the correct year of this reference. In the reference list, it is 2020. -> check all the same references you referenced in this paper.

877: Bleshta T. M. - unreferenced reference.

907: Dukhin, S.S, - unreferenced reference.

932: Grieg, D., - unreferenced reference.

1037: … Gasguet, 2018a, - remove tailing ‘a’

1242: “Abdulsamad et al, 2018” - reference missing.

1249, 1251: “Mahan et al,(1986)” and “Phillips (2010)” - reference missing.

1267, 1268: Ostrander and Zonge (1978), Vanhala (1997), De Witt(1979), Phillips (2010) - reference missing.

1280-1281: Ostrande and Zonge (1978), Collett(1959), Grisseman (1971) - reference missing.

1288-1289: Grissemann et al. (2000), Weller et al. (2008) - reference missing

1306: De Witt (1979) - reference missing.

1314-1315: Mahan et al., (1986), Phillips(2010), Gurin et al.,(2015) - reference missing.

1341: Hawai’i - Hawaii

1427: in Appendix A -> “Appendix A” is not found in this paper. It may be the Appendix of the original paper of Abdulsamad et al. (2020). --> It's desirable to get rid of this phrase so as to prevent getting confused.

1484, 1496, 1505: Kasaya et al, 2019 --> please check the year of this reference. (2020)

 

Author Response

Dr. André Revil                                                                                              08/04/2022

EDYTEM, rue mer Caspienne,

Université de Savoie Mont-Blanc,

Campus Universitaire Savoie Technolac,

73376 cedex, Le Bourget du Lac, France.                             To: The Editor of Minerals

andre.revil@univ-smb.fr                                                         Dr. Dale Du

1. 33+(0)675 580 075

 

Dear Dr. Dale Du,

Please find enclosed the revised version of the manuscript for the special issue "Advances in Electrical Resistivity and Electromagnetic Imaging Methods of Mineral Deposits and Mining Wastes". We hope that you will find this manuscript interesting and suitable for your journal. All the authors agree with the revision of the manuscript. The changes in the revised version of the manuscript are underlined in yellow. Thanks for the professional handling of the manuscript.

Best regards

André Revil

 

Referee 1

 

1. The Referee wrote “This paper is judged to be a paper that reviewed the basic theory, especially for the polarization phenomena and the applicability of the induced polarization (IP) exploration technique to the field of mineral exploration. Unlike other review papers published before, the authors paid special attention to the mathematical formulation of IP effects that occurred in the minerals, compared and verified its results with those obtained through laboratory experiments, and explained how mineral particles affect IP measurements. And several field cases are also presented to illustrate its usefulness. The factors that cause the IP phenomenon vary greatly from case to case and are complicated. So it is generally recognized that it is nearly impossible to explain all the real phenomena with a single mathematical model. Nevertheless, the theories reviewed in this paper which are based on some special assumptions could give the researcher who is interested in the IP method a useful insight concerning the interpretation of IP data. Eventually, it will be of great help in applying it to real data..” Response: We deeply thank the referee for his very positive assessment of our manuscript.

 

2. The Referee wrote “The overall contents, composition, and explanation are considered appropriate. However, there seem to be some parts that need additional explanation or modification in the content. if you supplement the relevant information a little more, it will help the interested reader to understand the usefulness of the IP method..” Response: We agree. The text has been enriched with additional information in order to make it more didactic:

 

3. The Referee wrote “I have summarized some comments as follows. I hope I would help you revise your paper1. It would be better if you add more explanation about the IP method in the frequency domain. Comparing the explanation of the time domain IP method, that of the frequency domain IP method seems to be too simplified or omitted in your paper. Although the term complex conductivity (resistivity) is greatly used in the explanation of the mathematical model and IP characteristic of a material, its detailed explanation is not found in this paper.” Response: Thanks for the comments. We have done more efforts to explain both the frequency- and time-domain measurements and their relationships. Note that the expression of the Cole Cole model is extensively presented for the complex conductivity and several spectra are shown and discussed. We hope that you will be satisfied by the revised version of our manuscript.

 

4. The Referee wrote “2. If possible, summarize the conclusions you draw in each chapter and then show them in a table. I think it will be helpful to the reader to understand the relationship between IP phenomena and the factors that cause IP effects.” Response: It seems quite unusual to put the conclusions in the table but we decided to improve the conclusion in that respect.

 

5. The Referee wrote “3.The format of some references is slightly different from others. Please check and modify the formats of these references. And there are many missing references in this paper. Please add appropriate references for them.” Response: We have carefully checked the references. Thanks for the suggestion.

 

6. The Referee wrote “Other minor corrections requests are summarized as follows. 62-63: Flekkoy et al., 2013 à reference missing” Response: Change done; Thanks.

 

7. The Referee wrote “119-120: Usually, the measurements are done in the time domain in the field or in the frequency domain in the laboratory. à In recent years, frequency domain exploration has been carried out a lot in the field, and the results have been published. This sentence is likely to lead to a misunderstanding that frequency-domain measurements are conducted only in laboratories. It’s better to comment that the use of frequency-domain IP measurement is conducted in the field these days.” Response: We fully agree with the referee that more and more studies are made in the frequency domain in the field. We have now cited such papers. That said, it truly does not matter to do the investigation in time-versus frequency-domain and nowadays, still most IP surveys are carried out in the time-domain in the field since all the resistivity meters can perform TDIP. The following sentence was added to the manuscript “That said, there are more and more field investigations based on frequency-domain induced polarization measurements (Flores Orozco et al., 2012a, b; Kemna et al., 2014; Günther and Martin, 2016; Revil et al., 2021).”.

 

8. The Referee wrote “165: i.e. Direct Current DC condition -> Direct Current (DC) condition”. Response: We agree. Change done.

 

9. The Referee wrote “232: De Witt, 1979 - reference missing.” Response: This reference has been added to the reference list. Thanks. 10. The Referee wrote “244: Abdulsamad et al.2017 - Abdulsamad et al., 2017 (insert comma)”. Response: We agree. Change done. 11. The Referee wrote “270: Wong, 1981 - check the year of reference. (1979 ?)” Response: Change done.  We agree. Change done.

 

12. The Referee wrote “345-346: But depends on the concentration of the charge… - incomplete sentence.” Response: Sentence changed to “Since the conductivity of the grains depends on the diffusion coefficient of the charge carriers , it means that is independent of the diffusion coefficient of the charge carriers in the metallic particle but depends on the concentration of the charge carriers in these metallic particles (Shuey, 1975; Pridmore and Shuey, 1976).”

 

13. The Referee wrote “349: Abdulsamad et al.2017 - Abdulsamad et al., 2017 (insert comma)” Response: We agree. Change done.

 

14. The Referee wrote “363: Sen et al., 1981n  - remove “n”” Response: Change done. 15. The Referee wrote “474: grain size size .--> remove repeated word “size”” Response: Change done. 16. The Referee wrote “560: Siegel (1959) - Seigel (1959)”. Response: Change done.

 

17. The Referee wrote “605: equations 16 and 17 - equation (59) and (60)” Response: We agree. Change done.

 

18. The Referee wrote “634-637: Please add the mathematical definition of normalized chargeability and quadrature conductivity. The definition of normalized chargeability appears in the figure caption in Fig. 31. The term normalized chargeability and quadrature conductivity appear suddenly in this paragraph.” Response: We fully agree. Line 194, we have added the following sentence “Hereinafter, we will also use the normalized chargeability, i.e., the product of the chargeability by the electrical conductivity M_n = M = which better characterize the polarization process alone.” And Line 149, we have added “The in-phase and quadrature conductivities corresponds to the real and imaginary parts of , i.e.,  and .”

 

19. The Referee wrote “745-745: SSIP (spread spectrum induced polarization) - Abbreviation and original sentences are used together. After the initial definition, it would be better to use SSIP terminology only.” Response: Done, but we do not call again this tern after this sentence.

 

20. The Referee wrote “755: VMS (Volcanogenic massive sulfide) - please, add the definition of VMS.” Response: yes we agree. Change done.

 

21. The Referee wrote “776: Zondres2D - ZondRes2D” Response: Change done.

 

22. The Referee wrote “792: SMS (seafloor massive sulfides) - I think it would be better to unify the terms afterward.” Response: We agree. Change done.

 

23. The Referee wrote “806: Kasaya et al (2019) – check the correct year of this reference. In the reference list, it is 2020. -> check all the same references you referenced in this paper.” Response: thanks. We agree. Change done. 24. The Referee wrote “877: Bleshta T. M. - unreferenced reference.” Response: Change done. 25. The Referee wrote “907: Dukhin, S.S, - unreferenced reference.” Response: Change done. 26. The Referee wrote “932: Grieg, D., - unreferenced reference.” Response: Change done. 27. The Referee wrote “1037: … Gasguet, 2018a, - remove tailing ‘a’” Response: We agree. Change done. Thanks.  28. The Referee wrote “1242: “Abdulsamad et al, 2018” - reference missing.” Response: Thanks. We have added these references to the new version of the manuscript. 29. The Referee wrote “1249, 1251: “Mahan et al,(1986)” and “Phillips (2010)” - reference missing.” Response: Thanks. We have added these references to the new version of the manuscript. 30. The Referee wrote “1267, 1268: Ostrander and Zonge (1978), Vanhala (1997), De Witt(1979), Phillips (2010) - reference missing.” Response: Thanks. We have added these references to the new version of the manuscript.

 

31. The Referee wrote “1280-1281: Ostrande and Zonge (1978), Collett(1959), Grisseman (1971) - reference missing.” Response: References added. 32. The Referee wrote “1288-1289: Grissemann et al. (2000), Weller et al. (2008) - reference missing” Response: References added. 33. The Referee wrote “1306: De Witt (1979) - reference missing.” Response: References added. 34. The Referee wrote “1314-1315: Mahan et al., (1986), Phillips(2010), Gurin et al.,(2015) - reference missing.” Response: References added. 35. The Referee wrote “1341: Hawai’i – Hawaii” Response: Actually this is the correct spelling.

 

36. The Referee wrote “1427: in Appendix A-> “Appendix A” is not found in this paper. It may be the Appendix of the original paper of Abdulsamad et al. (2020). --> It's desirable to get rid of this phrase so as to prevent getting confused.” Response: Yes, it has been removed. Thanks.

 

37. The Referee wrote “1484, 1496, 1505: Kasaya et al, 2019 --> please check the year of this reference. (2020)” Response: We agree. Change done. Thanks.

Reviewer 2 Report

see attached document

Comments for author File: Comments.pdf

Author Response

Referee 2

 

1. The Referee wrote “Minerals-1656407 Induced Polarization as a Tool to Assess Mineral Deposits: a Review By A. Revil et al. Comments It is a challenge to write a good review paper. The authors have compiled a comprehensive manuscript that includes a variety of issues of induced polarization. I acknowledge the wide range of topics that are presented in the submitted manuscript. Most of the results originate from studies that have been focused on the IP response of porous media with metallic particles. A series of ten papers has been published in Geophysics between 2015 and 2019 (see list of references). A large number of text sections and figures from earlier papers are adapted or modified for this manuscript. However, I doubt whether the compilation fulfills the requirements of a review paper that should provide an overview on the state of the art of the technology for interested readers including those of neighboring fields (e.g., mineralogists, geologists, and mining engineers).”

 

Response: Our goal here is to present a consistent induced polarization model that can explain all the observations. The literature has been plagued with potential models that fail to explain all the data. What we want to show is that the new model is not only based on a rigorous physics but we also explain why previous models fail. To our knowledge; this has never been done before. We want to show that our model is physics-based and this is why we show where the proposed relationships are coming from. There are not empirical or not from assumptions not supported by the underlying physics. Regarding the effect of the mineralogy, we do not see any mineralogical effects. We believe that looking for a mineralogical effect in induced polarization data has been a lost of time in the literature. At least in the realm of linear induced polarization, there is no evidence of any mineralogical effects from ores on IP. The reasons are well-explained in the paper. Regarding tomography we believe that we provide a state-of-the art discussion of the topic. It is true that we did not discussed new equipments in the manuscript but this is our choice since the paper is already quite long and we cannot consider all the aspects of induced polarization in this paper. We thank the referee for his useful comments and the time spent on our manuscript. We have tried also to be more didactic in the captions of the figures.

 

2. The Referee wrote “The extensive mathematical derivations (e.g., chapter 3.2) are of interest only for specialists who will read the original papers. Most of the figures are of good quality. However, I fear that the key messages of some figures cannot be understood without looking in the original papers.” Response: We disagree with this statement. We believe that this is important to discuss the origin of the polarization mechanisms at play for metallic particles especially because we disagree with previous models such as presented in Wong (1979) and Bücker et al. (2018a, b) discussed in the revised version of the manuscript. We argued the same in the past about the polarization mechanism for rocks without metallic particles. That said, we have tried to make the paper very didactic. We hope that you will be satisfied by the revised version of the manuscript.

 

3. The Referee wrote “The IP response of volcanic rocks is of minor interest for the assessment of mineral deposits (Figure 21). I would prefer to see a model of an ore body for the modelling and inversion in Figure 19. I recommend a careful revision of the manuscript that should address the comments listed below. Comments and recommended corrections:” ” Response: Actually we disagree regarding the comment with the volcanic rocks since a lot of ore bodies are found in geothermal systems associated with volcanoes, i.e., the so-called VMS (Volcanogenic massive sulfide) deposits. Thanks for the other comments.

 

4. The Referee wrote “Lines 111, 950: Olhoef -> Olhoeft Line 139: Figure 5 -> Figure 4 Line 183: the equation for f(iω) is not correct (wrong limit for the high frequency limit); use exponent -1 to get the Debye model. ” Response: the spelling of Olhoeft has been corrected. We have replaced Figure 5 by Figure 4 line 139. The equation for the reflection coefficient has been corrected; Thanks.

 

5. The Referee wrote “Line 190: wrong reference: Seigel (1959) did not mention the Cole-Cole model; Line 193: place equation 7 here to define M; ” Response: Good catch regarding Seigel. Youa re totally right. Reference removed. We have moved equation 7 per your request;

 

6. The Referee wrote “Line 221: equation(2.7) ??? Line 228: Considering eq. 7, eq. 10 is an approximation for ≈; please provide a comment; Line 328: Figure 12 -> Figure 10 ? ” Response: L.221, the sentence has been replaced by “From these considerations and using equation (4), we obtain”. Equation 10 has bene changed. Line 328, we have replaced Figure 12 by Figure 10.

 

7. The Referee wrote “Line 334: grain size > 500 µs represents a strong restriction; discuss the τ – a – relationship for smaller particles; add a reference to the paper of Bücker et al. (2018, DOI: 10.1190/GEO2017-0401.1) that includes smaller particles” Response: Good point. We agree. The two papers by Bücker et al. (2018a,b) have been added to the manuscript.

 

8. The Referee wrote “Line 449f: check formulation with repetition” Response: Done. 9. The Referee wrote “Line 512: provide the values of conductivity of the background material in Figures 14 and 15” Response: Background conductivity s_b ~10^-2-10^-3 S m^-1. This is now explained in the new version of the manuscript. 10. The Referee wrote “Line 553: being insulting ??? ” Response: Sorry “insulating”. We apologize for the mistake.

 

11. The Referee wrote “Line 605: check references to equations 16 and 17 Line 634: explain the term normalized chargeability; ” Response: Sure. These two corrections have been addressed. The normalized chargeability and the quadrature conductivity are now defined earlier in the manuscript. 12. The Referee wrote “Line 674: check: 2 x “in time domain” ” Response: Change done.

 

13. The Referee wrote “Line 755: explain the abbreviation VMS; Line 779: use chargeability instead of polarizability or define the difference; Line 792: explain the abbreviation SMS; Line 1148: add a reference to the source of this figure; ” Response: VMS is now explained “VMS (Volcanogenic massive sulfide) deposits”. Polarizability has been replaced by chargeability per your request. SMS is now explained (seafloor massive sulfide deposits). Figure 1 is a new figure.

 

14. The Referee wrote “Line 1156: add a reference to the source of this figure; Line 1218: I do not see an electrical dipole inside the grain ” Line 1156 the figure has been changed from previous figures. Response: regarding the dipoles, we are interested only by the potential distribution away from the grain and especially in the far field.

 

15. The Referee wrote “Line 1221: fractioon ??? Line 1226: time relaxation ??? Line 1351: provide references to textbooks; Line 1382: disseminated pyrite -> bentonite; Line 1407: relaxation times are not shown in this figure” Response: Change done. Note that the relaxation times are shown from the peaks of the quadrature conductivity.

 

16. The Referee wrote Line 1424: not all “black” filled circles are black; Line 1427: I cannot find Appendix A in this manuscript; Use of symbols: Line 818: φ is self-potential; Line 1141: φ is phase” Response: Actually the choice of the colors for the filled symbols is correct. Thanks for noting the error with Appendix A. We have changed the symbol for the phase. Thanks.

 

17. The Referee wrote “Missing references in the list: Lines 232, 1268, 1306: De Witt, 1979 Line 270: Wong, 1981 Lines 1171, 1249: Mahan et al., 1986” Response: Corrections done. 18. The Referee wrote “Line 1242: Abdulsamad et al., 2018” Response: Change done. 19. The Referee wrote “Lines 1251, 1268: Phillips, 2010” Response: Change done.  20. The Referee wrote “Lines 1267, 1280: Ostrander and Zonge, 1978” Response: Change done.  21. The Referee wrote “Line 1267: Vanhala, 1997” Response: We agree. Change done.  22. The Referee wrote “Line 1280: Collett, 1959 Line 1281: Grissemann, 1971” Response: Change done.  23. The Referee wrote “Line 1288: Grissemann et al., 2000 Lines 1289, 1291” Response: Change done.

 

24. The Referee wrote “Weller et al., 2008 Line 1313” Response: There was a typo. This is the paper of Nordsiek and Weller (2008). This has been corrected. Thanks. 25. The Referee wrote “Revil et al., 2019b -> 2019 (correct in the legend, too) Line 1337” Response: We agree. Change done. Thanks. 26. The Referee wrote “Soueid Ahmet et Revil, 2018 Correct references in the list: Line 877: ” Response: We agree. Change done. Thanks.

 

27. The Referee wrote “Baleshta … not used in the text; Line 908” Response: Removed. 28. The Referee wrote “Dukhin … not used in the text; Line 932” Response: Removed. 29. The Referee wrote “Greig … not used in the text; Line 1037” Response: Removed. 30. The Referee wrote “Revil et al., 2018a -> 2018” Response: Change done.

 

Round 2

Reviewer 2 Report

The revision has improved the manuscript. It is now acceptable for publication.

Author Response

Thank you so much for your comments.