Aqua Traiana, a Roman Infrastructure Embedded in the Present: The Mineralogical Perspective

Round 1

Reviewer 1 Report

Dear respected Editor

The manuscript; Aqua Traiana: a Roman infrastructure embedded in the present, is reviewed. 

the context of the thematic illustration is clear for understanding and the methodology is sufficient enough. But, regarding two points mention bellow I suggest a minor revision, before acceptance to this paper.

Only from the line 157-169, many parts are repeated frequently and therefore is better to rewrite again.

EMP is listed as one of the main methods to characterize the provenance but we have a few result of this method. I suggest to add some results regarding this key methods again.

Thank you for letting me to make a look through this interesting paper.

Author Response

REVIEWER #1

Dear respected Editor

The manuscript; Aqua Traiana: a Roman infrastructure embedded in the present, is reviewed. 

the context of the thematic illustration is clear for understanding and the methodology is sufficient enough. But, regarding two points mention bellow I suggest a minor revision, before acceptance to this paper.

 

1. Only from the line 157-169, many parts are repeated frequently and therefore is better to rewrite again.

Response: We agreed with the Reviewer; therefore, we rewrote this part, also according to the other reviewer’s suggestions (lines 152-184).

 

2. EMP is listed as one of the main methods to characterize the provenance but we have a few result of this method. I suggest to add some results regarding this key methods again.

Response: We strongly believe that EMP is fundamental in the study of mortars and building materials in general. Specifically, it may give a fundamental contribution on the provenance issue. This is the reason why we are currently deepening the subject with an increased number of samples and collecting a systematic overview of the mineralogical assemblage in the mortars from Aqua Traiana (as added in lines 371-378). However, we also believe that this paper, which stands as a preliminary characterization of the building materials of the aqueduct, would better keep the focus on a general overview of either mortars, bricks or cocciopesto samples, and should come out weighted down by the comprehensive characterization of a huge number of mortar samples.

 

Thank you for letting me to make a look through this interesting paper.

 

Reviewer 2 Report

I think this is a methodologically sound article that offers very clear results. Moreover, its structure and language are very expository.

Both the pictures and the tables provided are clarifying and in line with the contents of the article. However, I do not understand the call for figure 1 in line 48. One would expect to find a photograph or elevation of the aqueduct representing its construction phases and typologies (ideally, an archaeological reading of paraments). Likewise, the layout of the aqueduct would be better understood if it were depicted on a topographical map. Both materials would be highly illustrative for an audience unfamiliar with the monument and would reinforce the contextualisation of the article. The very title of the paper ("a Roman infrastructure embedded in the present") perhaps invites a representation of the aqueduct in its current state of preservation. I would also like to point out that figure 1 is not very sharp and pixelated. It is also difficult to appreciate the differences between the samples due to their small size.

Concerning the methodology, I cannot object to the analytical procedures and I agree with the observations made by the authors from the results. My main criticism lies in the fact that the authors assign a specific chronology to the samples (Roman or Papal) from the outset, without explaining what criteria they have followed (archaeological, chronotypological, architectural) or absolute dating systems have used. Although the results support this characterisation, apriorisms should be avoided.

As for the conclusions, I find them excessively brief and recapitulatory. Perhaps a little more could be said about the present and future activities carried out in the framework of this research project in order to highlight the importance of the results obtained at Aqua Traiana.

In the sense of all my comments and as a bibliographical complement, I recommend the authors to review the following papers:

https://doi.org/10.1016/j.jas.2010.04.008

https://doi.org/10.1007/s12520-018-0655-1

Author Response

REVIEWER #2

I think this is a methodologically sound article that offers very clear results. Moreover, its structure and language are very expository.

Both the pictures and the tables provided are clarifying and in line with the contents of the article.

 

1. However, I do not understand the call for figure 1 in line 48. One would expect to find a photograph or elevation of the aqueduct representing its construction phases and typologies (ideally, an archaeological reading of paraments). Likewise, the layout of the aqueduct would be better understood if it were depicted on a topographical map. Both materials would be highly illustrative for an audience unfamiliar with the monument and would reinforce the contextualisation of the article.

Response: We agree with the reviewer. However, since the paper is intended as a focus on the distinctive mineralogical features of the aqueduct and the literature on its archaeological description already exists and may not be the first interest of the addressed readers of Minerals, we decided to provide a more exhaustive bibliography on the issue, for those who are specifically interested in it (References [19-20]).

 

2. The very title of the paper ("a Roman infrastructure embedded in the present") perhaps invites a representation of the aqueduct in its current state of preservation.

Response: We agree with the Reviewer, and we slightly modified the title to clarify that this is a preliminary study on the mineralogical characterization of its building materials: “Aqua Traiana, a Roman infrastructure embedded in the present: the mineralogical perspective”.

 

3. I would also like to point out that figure 1 is not very sharp and pixelated. It is also difficult to appreciate the differences between the samples due to their small size.

Response: We agreed with the Reviewer, we provided a new version of Fig. 1 at higher resolution.

 

4. Concerning the methodology, I cannot object to the analytical procedures and I agree with the observations made by the authors from the results. My main criticism lies in the fact that the authors assign a specific chronology to the samples (Roman or Papal) from the outset, without explaining what criteria they have followed (archaeological, chronotypological, architectural) or absolute dating systems have used. Although the results support this characterisation, apriorisms should be avoided.

Response: The specific chronology was assigned following archaeological criteria. Archaeologists were in fact present during the sampling and helped the distinction of Roman and Papal samples to be taken for their mineralogical characterization. We specified it in the text (lines 99-101).

 

5. As for the conclusions, I find them excessively brief and recapitulatory. Perhaps a little more could be said about the present and future activities carried out in the framework of this research project in order to highlight the importance of the results obtained at Aqua Traiana.

In the sense of all my comments and as a bibliographical complement, I recommend the authors to review the following papers:

https://doi.org/10.1016/j.jas.2010.04.008

https://doi.org/10.1007/s12520-018-0655-1

Response: We thank the reviewer for providing appropriate reference, which we included in the introduction (References [5,6]). We found the comment in agreement with the research strategy, ongoing and planned, for the future characterization of the building materials at Aqua Traiana. We hence modified the conclusions (lines 371-378).

 

Reviewer 3 Report

The paper titled "Aqua Traiana: a Roman infrastructure embedded in the present" by M. Botticelli et al. deals with the mineralogical characterization of construction materials belonging to the internal ducts of Aqua Traiana, a Roman aqueduct built in 109 AD. In particular, 20 samples (including mortars, bricks and cocciopesto), were collected and analysed through different complementary optical and spectroscopic techniques, providing a complete scenario of the production technology employed, provenance and physico-chemical composition. Results obtained also allowed a proper distinction of the original materials (Trajan age) from those applied during the restauration of Pope Paul V, furnishing an experimental evidence of the presence of two building phases.

In my opinion, it is a well-written thorough systematic study of high technical quality. The reported data are accurate and the main discussion is detailed and rigorously described.

The paper is suitable for publication in Minerals after addressing just few minor comments.

1. Line 27: Since the literature on this subject is extremely broad, I would suggest to add, after [4], of the many references the following ones: DOI: 10.3390/min8060255, DOI: 10.3390/geosciences9040172 and DOI: 10.5281/zenodo.44896, in order to further reinforce the corresponding statement (lines 25-28).
2. Line 48: Being Figure 1 composed of two different panels (a and b), please specify the panel you are referring to.
3. Line 78: Being Figure 1 composed of two different panels (a and b), please specify the panel you are referring to.
4. Figure 1: It is hardly visible. The Geological map of the Sabatini Volcanic District (a) as well as the segment of the aqueduct with location of each sampling point and corresponding sample (b) display a severe low resolution which make their content scarcely readable. Furthermore, the light red line in Figure 1a can be barely distinguished as also the five main phases stated at lines 77-78. I would strongly recommend to provide a high-quality figure, as it would allow the reader to properly visualize the materials and sampling sites that are the subject of this study, which is not possible at this stage.
5. Figure 1b: It seems that Figure 1b is actually composed of 12 sub-panels (A-N). Please, once replaced with a high-resolution figure, specify in the Figure caption a brief description of such panels.
6. Line 95: "...northern area of Lake Bracciano." Please change in "...northern area of Lake Bracciano (Rome, Italy)."
7. Lines 157-166: Why, in authors opinion, papal restoration samples show higher amount of Calcite with respect to all the remaining Trajan Age samples? please include some additional specifications on this point within the text.
8. Although the writing looks pretty good to me, occasionally an incorrect choice of wording was chosen. Rewriting with a native English speaker is recommended.

 

Author Response

REVIEWER #3

The paper titled "Aqua Traiana: a Roman infrastructure embedded in the present" by M. Botticelli et al. deals with the mineralogical characterization of construction materials belonging to the internal ducts of Aqua Traiana, a Roman aqueduct built in 109 AD. In particular, 20 samples (including mortars, bricks and cocciopesto), were collected and analysed through different complementary optical and spectroscopic techniques, providing a complete scenario of the production technology employed, provenance and physico-chemical composition. Results obtained also allowed a proper distinction of the original materials (Trajan age) from those applied during the restauration of Pope Paul V, furnishing an experimental evidence of the presence of two building phases.

In my opinion, it is a well-written thorough systematic study of high technical quality. The reported data are accurate and the main discussion is detailed and rigorously described.

The paper is suitable for publication in Minerals after addressing just few minor comments.

 

1. Line 27: Since the literature on this subject is extremely broad, I would suggest to add, after [4], of the many references the following ones: DOI: 10.3390/min8060255, DOI: 10.3390/geosciences9040172 and DOI: 10.5281/zenodo.44896, in order to further reinforce the corresponding statement (lines 25-28).
   Response: We agreed with the reviewer and we included the references, which are now numbered as 7-9.

 

2. Line 48: Being Figure 1 composed of two different panels (a and b), please specify the panel you are referring to.
3. Line 78: Being Figure 1 composed of two different panels (a and b), please specify the panel you are referring to.

Response: We included the panels in lines 49, 79, 95, 173, and 176.

 

4. Figure 1: It is hardly visible. The Geological map of the Sabatini Volcanic District (a) as well as the segment of the aqueduct with location of each sampling point and corresponding sample (b) display a severe low resolution which make their content scarcely readable. Furthermore, the light red line in Figure 1a can be barely distinguished as also the five main phases stated at lines 77-78. I would strongly recommend to provide a high-quality figure, as it would allow the reader to properly visualize the materials and sampling sites that are the subject of this study, which is not possible at this stage.

Response: We provided a high-quality figure, as recommended by the Reviewer.

 

5. Figure 1b: It seems that Figure 1b is actually composed of 12 sub-panels (A-N). Please, once replaced with a high-resolution figure, specify in the Figure caption a brief description of such panels.

Response: We provided the lettering in the caption. However, we believe that a detailed description of each sample is provided in Table 1 and should not be also given in the caption of Fig. 1, to avoid repetitions. Therefore, Table 1 is cited in the caption too.

 

6. Line 95: "...northern area of Lake Bracciano." Please change in "...northern area of Lake Bracciano (Rome, Italy)."

Response: We modified the text as suggested by the reviewer (line 97).

 

7. Lines 157-166: Why, in authors opinion, papal restoration samples show higher amount of Calcite with respect to all the remaining Trajan Age samples? please include some additional specifications on this point within the text.

Response: We briefly justified the absence of calcite, despite this is not the prominent subject of this paper and will be the focus of upcoming studies (lines 167-169).

 

8. Although the writing looks pretty good to me, occasionally an incorrect choice of wording was chosen. Rewriting with a native English speaker is recommended.

Response: The manuscript has been revised by a native English speaker before the new submission and corrections are marked in the text.

Reviewer 4 Report

This is an interesting paper describing the mortars used in the construction of the Aqua Traiana aqueduct, distinguishing the original parts from those restored in the 17^th century under Pope Paul V. The paper is well written, and conclusions supported by the data. Therefore, I suggest accepting this paper for publication after minor revisions. Here my suggestions follow:

Lines 25-27: More general references should be cited here, e.g. to review papers. For example, instead of (or in addition to) Botticelli et al., 2020, a paper such as Maritan (2019, Archaeol. Anthropol. Sci., 11, 5085-5093) should be cited.

Lines 83-88: In addition to the Italian wording, authors should write the translation in English, at least the at the first occurrence. Thus:  “…. Tufo Giallo (yellow tuff) of Via Tiberina ….”, “… Tufo Giallo (yellow tuff) of Prima Porta …”, and “… Tufo Rosso (red tuff) with Scorie Nere (black scoria) …” (please use “of” instead of “della” and “di”, and “with” instead of “a”).

Figure 1a: Please use “black scoria” instead of “black scorias”.

Caption of table 2:”… relative abundance …”: please specify how you obtained (semi-quantitative?) relative abundance (besides saying that they are derived from XRPD data).

Line 163: “Micaceous materials”: do authors mean “Sheet silicates”?

Line 265: “… vitreous fraction …”: not necessarily reactive fraction is vitreous; it could be the amorphous phase, especially considering materials fired at relatively low temperature.

Line 278: please, replace “della” with “of”.

Line 283: please, replace “a” with “with”.

Line 300: please, replace “della” with “of”.

Table 4: please consider rotating table 4. It should fit into a single page.

 

 

Author Response

REVIEWER #4

This is an interesting paper describing the mortars used in the construction of the Aqua Traiana aqueduct, distinguishing the original parts from those restored in the 17^th century under Pope Paul V. The paper is well written, and conclusions supported by the data. Therefore, I suggest accepting this paper for publication after minor revisions. Here my suggestions follow:

 

1. Lines 25-27: More general references should be cited here, e.g. to review papers. For example, instead of (or in addition to) Botticelli et al., 2020, a paper such as Maritan (2019, Archaeol. Anthropol. Sci., 11, 5085-5093) should be cited.

Response: We agreed with the Reviewer, we included the suggested reference, numbered as 10.

 

2. Lines 83-88: In addition to the Italian wording, authors should write the translation in English, at least the at the first occurrence. Thus:  “…. Tufo Giallo (yellow tuff) of Via Tiberina ….”, “… Tufo Giallo (yellow tuff) of Prima Porta …”, and “… Tufo Rosso (red tuff) with Scorie Nere (black scoria) …” (please use “of” instead of “della” and “di”, and “with” instead of “a”).

Response: We provided English translation for each typology, according to the Reviewer’s suggestion (lines 84-92).

 

3. Figure 1a: Please use “black scoria” instead of “black scorias”.

Response: This is the terminology used by Buttinelli et al. (2011) [28], from which the original picture has been taken and modified, therefore we have decided to keep the original legend.

 

4. Caption of table 2:”… relative abundance …”: please specify how you obtained (semi-quantitative?) relative abundance (besides saying that they are derived from XRPD data).

Response: As reported in “Methods” paragraph, the semi-quantitative analysis is calculated by Reference Intensity Ratios (RIR) method in XPowderX. We specified it also in the caption of Table 2.

 

5. Line 163: “Micaceous materials”: do authors mean “Sheet silicates”?

Response: We used the terminology “micaceous minerals” and we believe it is appropriate for biotite.

 

6. Line 265: “… vitreous fraction …”: not necessarily reactive fraction is vitreous; it could be the amorphous phase, especially considering materials fired at relatively low temperature.

Response: According to the reviewer we modified the sentence (line 275):

 

7. Line 278: please, replace “della” with “of”.

Line 283: please, replace “a” with “with”.

Line 300: please, replace “della” with “of”.

Response: We provided appropriate reference for tuff typologies, which are there mentioned in Italian, as they are also described in the geological setting of our paper. Therefore, we decided to keep the Italian full name with the English translation in brackets even in the discussion.

 

8. Table 4: please consider rotating table 4. It should fit into a single page.

Response: We modified the table according 

Reviewer 5 Report

The paper “Aqua Traiana: A Roman infrastructure embedded in the present” by Botticelli et al. provides mineralogical and petrographical analyses of mortars and bricks of a Roman aqueduct in order to differentiate the original material and papal restoration as well as to define the provenance of the material.

In my opinion the geological setting is very short, describing only the different volcanic rocks outcropping in the Sabatini Volcanic district but without entering in detail into the mineralogy of the rocks. Only in the discussion, when illustrating the minerals found in the mortars, the authors will illustrate part of the mineralogy of the rocks. In such a way, however, the reader has not the possibility of making his own idea because of the information that are missing. Moreover, it is to point out that the authors does not illustrate other possible sources, but only those in the Sabatini area. It seems they already choose this area as the provenance.

In their description of thin sections, the authors wrote this paragraph (lines 160-166):

On the contrary, the original Trajan Age samples are characterized by the absence of calcite and a more abundant presence of clinopyroxene, clay minerals being present or in trace. Alkali feldspars are generally very abundant or abundant. Micaceous minerals, specifically biotite, are ubiquitous in lower amount. A feldspathoid typical of the Roman volcanic activity, leucite, was identified only in sample TRA 6, as already found by OM. Traces of clinopyroxene were found in TRA 14 and quartz in sample TRA 11.

However, this is something different from what we can read in Table 2. First of all, I would say that there are two groups of samples with different feldspar amount (it is written that alkali feldspar are generally very abundant or abundant). In fact in samples from TRA12 to 24 it is true that they are abundant but in other samples they vary from trace (TRA8 and 11) to common ((TRA2). SO, I think that they need to change this paragraph in something like this:

On the contrary, the original Trajan Age samples are characterized by the absence of calcite and a more abundant presence of clinopyroxene, clay minerals being present or in trace. According to the presence of alkali feldspars the samples could be grouped in two. The first group presents abundant to very abundant content of alkali feldspars while in the second, they are in trace to common. Micaceous minerals, specifically biotite, are ubiquitous in lower amount. A feldspathoid typical of the Roman volcanic activity, leucite, was identified only in sample TRA 6. Traces of clinopyroxene were found in TRA21 and 24 and quartz in sample TRA 2.

However, it is hard to understand if the paragraph relates to OM description or XPRD. This should be clarified. I could understand the discrepancies between the text and the table if they are describing OM and XPRD, respectively. Moreover, I think that it would be better to add something about the presence of rock fragments. It seems they are present in all the samples but a better description of amounts and types of inclusions is required.

The authors present only one analyses of an augite crystal saying that it is representative of the augite crystals also found in other samples (line 238). It is unclear if the authors performed several analyses by EPMA and publishes only one because they are very close one another or if they have an evidence that all the augites are similar so that they need to publish only one. By the way, I recalculated the formula of the augite and it seems that there is something wrong in the one presented. This is particularly evident from the lack of Fe3+ in the formula, whereas an amount of Fe3+ higher than Fe2+ is commonly present in analyses of cpx from this area (Cundari, 1976; Del Bello et al., 2014). The recalculation of the formula I obtained is Si 1.699, Al 0.343, Fe3+ 0.298, Fe2+ 0.061, Mn 0.009, Mg 0.573, Ca 0.979, Na 0.039 corresponding to a Wo51En30Fs19 composition.

The conclusion is that the original bedding mortars were produced from a mixture of lime, water and fine-grained materials with pozzolanic behaviour. This material of volcanic origin, characterized by the presence of analcime, is commonly found in lithified deposits of the Tufo Giallo (lines 270-278). But, according to Cappelletti et al. (2015), the Tufo Giallo is characterized by the presence of about 10-15% of calcite. Calcite is the mineral discriminating papal restoration (where it is present) from original mortar (absent), so I would expect the Tufo Giallo being the possible source of the papal restoration material not of the Roman products. In my opinion, the authors should clarified these points and assign the possible sources in a way that will not contradict themselves.

Given this, I suggest its acceptance after major revisions.

Author Response

REVIEWER #5

The paper “Aqua Traiana: A Roman infrastructure embedded in the present” by Botticelli et al. provides mineralogical and petrographical analyses of mortars and bricks of a Roman aqueduct in order to differentiate the original material and papal restoration as well as to define the provenance of the material.

 

1. In my opinion the geological setting is very short, describing only the different volcanic rocks outcropping in the Sabatini Volcanic district but without entering in detail into the mineralogy of the rocks. Only in the discussion, when illustrating the minerals found in the mortars, the authors will illustrate part of the mineralogy of the rocks. In such a way, however, the reader has not the possibility of making his own idea because of the information that are missing. Moreover, it is to point out that the authors does not illustrate other possible sources, but only those in the Sabatini area. It seems they already choose this area as the provenance.

Response: in “Results and Discussion”, we have clarified the idea that the construction of Aqua Traiana involved several types of supplies, which could be possibly coming from different areas of the Roman Magmatic Province (lines 281-305). The same hypothesis is reported in the “Conclusions” section (lines 366-368):

We believe this issue is sufficiently remarked in the discussion and appropriate references are better placed here, instead of providing them in the introduction, when the reader is not yet aware of our findings.

 

2. In their description of thin sections, the authors wrote this paragraph (lines 160-166):

On the contrary, the original Trajan Age samples are characterized by the absence of calcite and a more abundant presence of clinopyroxene, clay minerals being present or in trace. Alkali feldspars are generally very abundant or abundant. Micaceous minerals, specifically biotite, are ubiquitous in lower amount. A feldspathoid typical of the Roman volcanic activity, leucite, was identified only in sample TRA 6, as already found by OM. Traces of clinopyroxene were found in TRA 14 and quartz in sample TRA 11.

However, this is something different from what we can read in Table 2. First of all, I would say that there are two groups of samples with different feldspar amount (it is written that alkali feldspar are generally very abundant or abundant). In fact in samples from TRA12 to 24 it is true that they are abundant but in other samples they vary from trace (TRA8 and 11) to common ((TRA2). SO, I think that they need to change this paragraph in something like this:

On the contrary, the original Trajan Age samples are characterized by the absence of calcite and a more abundant presence of clinopyroxene, clay minerals being present or in trace. According to the presence of alkali feldspars the samples could be grouped in two. The first group presents abundant to very abundant content of alkali feldspars while in the second, they are in trace to common. Micaceous minerals, specifically biotite, are ubiquitous in lower amount. A feldspathoid typical of the Roman volcanic activity, leucite, was identified only in sample TRA 6. Traces of clinopyroxene were found in TRA21 and 24 and quartz in sample TRA 2.

However, it is hard to understand if the paragraph relates to OM description or XPRD. This should be clarified. I could understand the discrepancies between the text and the table if they are describing OM and XPRD, respectively. Moreover, I think that it would be better to add something about the presence of rock fragments. It seems they are present in all the samples but a better description of amounts and types of inclusions is required.

Response: Thanks to the reviewer suggestions and based on a careful revision of our XRPD data, we were able to distinguish 2 sub-groups and hence we deeply modified the text (lines 170-176):

 

3. The authors present only one analyses of an augite crystal saying that it is representative of the augite crystals also found in other samples (line 238). It is unclear if the authors performed several analyses by EPMA and publishes only one because they are very close one another or if they have an evidence that all the augites are similar so that they need to publish only one.

Response: We collected data on several augite crystals, in sample TRA 11 and in other mortar samples. Since we found the overall composition quite comparable in these analyses, we decided to publish data only from one representative sample, for the sake of clarity and conciseness. Hence, we highlighted this aspect in the text, modifying one sentence (lines 247-248):

 

4. By the way, I recalculated the formula of the augite and it seems that there is something wrong in the one presented. This is particularly evident from the lack of Fe3+ in the formula, whereas an amount of Fe3+ higher than Fe2+ is commonly present in analyses of cpx from this area (Cundari, 1976; Del Bello et al., 2014). The recalculation of the formula I obtained is Si 1.699, Al 0.343, Fe3+ 0.298, Fe2+ 0.061, Mn 0.009, Mg 0.573, Ca 0.979, Na 0.039 corresponding to a Wo51En30Fs19 composition.

Response: We want to thank the Reviewer for this observation. Erroneously, we pasted a different formula, therefore we corrected Figure 4 and in addition, we normalized the wt% to 100.

5. The conclusion is that the original bedding mortars were produced from a mixture of lime, water and fine-grained materials with pozzolanic behaviour. This material of volcanic origin, characterized by the presence of analcime, is commonly found in lithified deposits of the Tufo Giallo (lines 270-278). But, according to Cappelletti et al. (2015), the Tufo Giallo is characterized by the presence of about 10-15% of calcite. Calcite is the mineral discriminating papal restoration (where it is present) from original mortar (absent), so I would expect the Tufo Giallo being the possible source of the papal restoration material not of the Roman products. In my opinion, the authors should clarified these points and assign the possible sources in a way that will not contradict themselves.

Response: we have clarified the discussion pointing out that the main aggregate is composed by red and black pozzolans, only rare yellow tuffs are identified. Therefore, in the total, the calcite content of these small and rare fragments could not have been detected by XRD analysis.

However, in the discussion (as answered at point 1) we highlighted that the construction of Aqua Traiana involved several types of supplies, which could be possibly coming from different areas of the Roman Magmatic Province (lines 281-305). For the first time we proved that they are compatible with the geological setting of the Sabatini Volcanic District and that we do not have to consider only Alban Hills products. We modified “Results and Discussions” section to clarify this point.

The calcite identified by XRD in Papal samples is related to the binder (as clarified in lines 161-162). Further analysis based on the separation of single type of aggregate will help in a deeper investigation (lines 373-378).

Round 2

Reviewer 5 Report

In  my opinion, the text really improved so I would like to suggest acceptance after one more small revision. It is written (lines 377) "and Rare Earth Elements (Hf, Ta and Th)". As Hf, Ta and Th are not REE, I think that there is something missing. Maybe the sentence should be something like "K, Sc, Ga, Rb, Cs, REE and other elements such as Hf, Ta and Th".