the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 25 Jul 2023
Magnetic properties and geochemistry of loess/paleosol sequences at Nowdeh section northeastern of Iran
Abstract. The loess-palesols sequences in the northeastern of Iran are high-resolution natural archive of climate and environmental change, providing evidence for the interaction between accumulation and erosion of aeolian and fluvial sediments during the Middle and Late Pleistocene. In this study, Azadshar (Nowdeh Loess Section) was selected to reconstruct Late Quaternary climate change. The Nowdeh loess/ paleosol sequences with 24 m thickness were sampled for magnetic and geochemical analysis. The section systematically and with high resolution (10 cm intervals) were sampled and totally 237 samples were taken. Magnetic susceptibility of all samples were measured in Environmental and Paleomagnteic laboratory based at Geological Survey of Iran, Tehran, Iran. The geochemical analysis of selected samples (peak of magnetic susceptibility) were included to assist the paleoclimatic interpretation of the magnetic signals. The result of magnetic susceptibility of Loess/paleosol deposits show low magnetic susceptibility values in cold and dry climate periods (Loess) and high magnetic susceptibility values in warm and humid climate periods (paleosoil). Comparison of magnetic and geochemical data show that the results of geochemical weathering ratio variations such as magnetic parameters variations are with magnetic susceptibility. High degree of coherency between the intensity of magnetic susceptibility and Rb/Sr, Mn/Ti, Zr/ Ti and Mn/ Sr ratio are confirmed.
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RC1: 'Comment on cp-2023-56', Anonymous Referee #1, 10 Aug 2023
The paper entitled “Magnetic properties and geochemistry of loess/paleosol sequences at Nowdeh section northeastern of Iran“ of Feizi et al. presents magnetic susceptibility and isothermal remanent magnetization data as well as geochemical ratios of sediment samples taken from the loess-paleosol sequence at Now Deh, a loess section located in the transition zone between the Caspian Lowlands and the steep northward facing slopes of Alborz Mountains. The sequence has been studied before, but the authors resampled it and provide new data. Although the paper addresses relevant scientific questions within the scope of CP, it shows many severe deficiencies. It is thus impossible to accept the paper in the present form. I doubt that the deficiencies will be overcome within the time provided until the resubmission deadline.
A very significant flaw is the language use, which makes it hardly possible to understand what the authors want to say. Many other shortcomings could be listed. The research question is not well elaborated and it remains unclear, why the study was conducted and why the section at Now Deh was selected for this investigation. The literature cited in the introduction and the discussion sections does not include recent studies on loess deposits in the area, although these also used rock magnetic and geochemical methods to derive paleoclimate proxy data for the area. The stratigraphy of Now Deh section is not described at all. It thus remains unclear, from where the investigated samples derive. The stratigraphic column of loess and paleosol layers presented in figures 2 to 4 will provide relevant information but is not referred to at all in the text. In addition, the dating results shown therein are not discussed against the background of other recently published luminescence ages for Northern Iranian loess deposits. It is also necessary to mention the correct source of the dating results in the text and the figure captions. The quality of all figures is low, some are difficult if not impossible to read.
Overall, the presentation of the chronostratigraphic context, the origin of the samples, and the data in the results section are not convincing. The discussion lacks clear structure and is below the standard of an international paper to be published in CP. Finally, the conclusions are too general and not supported by the presented data. Overall, I have to recommend rejection of the manuscript.
Citation: https://doi.org/10.5194/cp-2023-56-RC1 -
AC1: 'Reply on RC1', Vahid Feizy, 29 Aug 2023
Greetings and courtesy, respected referee
First of all, we need to thank you for your valuable time to review the article. The authors of this article would like to improve and increase the quality of the article with the help of you, respected referees. Therefore, all the cases mentioned by the respected referees are examined by the group of authors.
According to the explanations mentioned in the text of the article, loess sediments are one of the most important indicators of ancient climate reconstruction. The sequence of loess sediments in Nodeh section was investigated because this sequence was previously investigated by Kohl et al. in 2009 in relation to stratigraphy and climatic changes and had an acceptable age. Therefore, in this research, magnetic and geochemical reception methods have been investigated to obtain more details about the past climate changes in this region.
Regarding the question they have raised, the stratigraphy of the studied sequence has not been explained at all, it should be pointed out that the discussion of the stratigraphy of the Noda sediments sequence has been studied before and its rereading is a kind of repetition, so we tried to explain the stratigraphy of the Do not check. Regarding mentioning the source of historiography results, this can be corrected and will be corrected. Also, the quality of the figures can be changed and the shapes can be presented with a higher quality so that they can be recognized and read.
Citation: https://doi.org/10.5194/cp-2023-56-AC1
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AC1: 'Reply on RC1', Vahid Feizy, 29 Aug 2023
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RC2: 'Comment on cp-2023-56', Gerald Ganssen, 11 Mar 2024
The submitted manuscript entitled “Magnetic properties and geochemistry of loess/paleosol sequences at Nowdeh section northeastern of Iran” by Vahid Feizi et al. is a description of basic findings of the laboratory work from the sample site. Results are plotted against depth of the section (lithostratigraphy) only and not put into a chronostratigrahic framework. The data as given in the figures just show changes observed within 24 m of sediments. As no time frame is provided any discussion or conclusion of magnitude and rate in relation to climatic changes can be justified. Hence, the discussion and conclusions of the paper are speculations and lack any scientific evidence in relation to the Late Quaternary, as promised already in the abstract: “,,,selected to reconstruct Late Quaternary climate change”.
Hence the paper fails in providing any evidence for climate related changes.
In addition,
- the quality of writing is poor;
- sometimes it is not clear what the authors want to say;
- acknowledgements are missing: here it should have justified the relation to the topic of this SI.
Citation: https://doi.org/10.5194/cp-2023-56-RC2 -
AC2: 'Reply on RC2', Vahid Feizy, 06 Apr 2024
Thank you to the esteemed reviewer for dedicating time and guiding the authors in enhancing the article. In response to the esteemed referee, we would like to clarify that, as stated in the article, the dating of the specific section was conducted by Kohl et al. in 2009.The charts are included in the dates article. Thus, the case mentioned by the esteemed referee is excluded, and the article carries a scientific weight, supported by laboratory findings. The authors have attempted to rectify the writing and grammar issues in the revised version.
Citation: https://doi.org/10.5194/cp-2023-56-AC2
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RC3: 'Comment on cp-2023-56', Luigi Jovane, 16 Mar 2024
The manuscript Feizi et al. present the magnetic properties and geochemical results of a quaternary loess section Nowdeh in northeastern Iran. They use magnetic susceptibility and environmental magnetism to compare with Sr, Rb, Zr, Ti and Mn elements and ratios.
It is very important to receive more information of quaternary response to the Asian/Arabian monsoon system and interactions, so I am very supportive for this work also because it is obtained in an outcropping section and magnetic parameters.
However, the paper is still very immature and badly prepared
The introduction is fine but there are some references for the region and the topic which are missing and do not provide the information needed for the reader understand the present-day knowledge of the problem in general view. The methods are lacking the environmental magnetic and geochemical part. The results are also lacking information and present parameters that have never been showed. Moreover, they arrive to some assumption with no real scientific base which should need more magnetic studies. Discussions needs to be compared with the work in the section of region and period with more consistency. The resolution of the proxies in very low and I doubt can be successfully explain global or local signals.
In the introduction and discussions they also must include global view of this period from other works. Figures are very poor and badly prepared.
I think they should clearly show the sections pictures using previous works to make people understand where they are. Also, when discussion they must compare to Nowdeh sections to other sections of the same period.
Just to finish, they state some conclusions which are actually not mentioned in the entire paper, so are not supported by the discussions.
The paper cannot be accepted in this stage but after reformulation of the paper can obtain approval for publication in this journal.
Detailed comments:
Line 84: They state that there are dating but there is no reference and no dates are shown in the figure 1. Actually, the figure 1 is pretty poor. There is no geological, structural and ages of the soils.
Line 95: how many are the “all samples”? it seems that the MS resolution is much higher that the environmental magnetism parameters resolution. Why? It seems that there are only 15 samples of environmental magnetism… this is very low sampling resolution for an section of 24 meters,
Line 101: in which equipment have been measured the SIRM?
Line 119: Name NRM and why this is not described in the methods? Is it demagnetization? AF of Thermal?
Lines 123-124: add reference to this affirmation on magnetic signal of loess.
Line 133: What are Bw, Bt, Btk that have not been presented in the methods?
Line 140: specify the steps of the NRM demagnetization.
Lien 142: what are BW and BWK?
Line 148: Deterrent? What do you mean? They speak of goethite, maghemite, hematite increase, but this should be in the discussions and it is not clear which are the base to affirm this.
Line 149: S(-0.3T) is a very strange way to call the S-ratio which is also different from the methods at Line 110.
Figure 2: Environmental magnetic parameters missing units. Numbers are illegible. The lithological description and legend are unreadable. Overall quality of the figure is very bad. Actually, all figures are very poor and immature.
Line 156: who measured those geochemistry parameters? Which reference? If they did it which equipment and method? How many samples?
Line 227: typo of loees for loess
Line 235: I cannot see the brown layers in the figure 3
Line 252: I do not understand how magnetic intensity is related to glacial-interglacial. The phrase is badly written and the concept is very immature.
Line 260: typo – change “t0” for “to”.
Line 265: typo - .last years’s ka???
Line 275: typo – in in
Line 319: where they show coherency in the paper?
Citation: https://doi.org/10.5194/cp-2023-56-RC3 -
AC3: 'Reply on RC3', Vahid Feizy, 07 Apr 2024
The comment was uploaded in the form of a supplement: https://cp.copernicus.org/preprints/cp-2023-56/cp-2023-56-AC3-supplement.pdf
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AC3: 'Reply on RC3', Vahid Feizy, 07 Apr 2024
- AC4: 'Comment on cp-2023-56', Vahid Feizy, 07 Apr 2024
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