Review Reports - Genesis of the Wuzhutang Granite and Associated W–Sn–Be Mineralization in the Xuebaoding Mining Area, Sichuan Province, China

Round 1

Reviewer 1 Report

The paper is well written although some grammar mistakes are here and there. The main issue is that the Wuzhutang granite without visible Eu negative anomalies. ASI is lower than 1.1. Do you believe it is a highly differentiated granite and related to rare metal mineralization? It has different Sr-Nd isotopic compositions from those of PLK and PK granites, so they can't be originated from the same metasedimentary rocks. It's more likely that the Wuzhutang granite has nothing to do with (predate) mineralization in this area and may contain more mantle component than PLK and PK or just has totally different magmatic source than PLK and PK.

Comments for author File: Comments.pdf

Author Response

Reply to the Reviewer 1

Dear reviewer:

I would like to express my great appreciation to you for your constructive suggestions. Since I'm currently working in the field, sorry for some unsatisfactory answers. My responses for your questions are as follows:

Point 1: What structures? the Zibaishan dome? (Line 15)

Response 1: The term of “these structures” refers to the Wuzhutang granite and nearby ore bodies mentioned above. We realized that this expression is inappropriate here, and the words “these structures” has been replaced by the pronoun “them” in the manuscript.

Point 2: The word “concentrations” in line 37

Response 2: The word “concentrations” in line 37 has been replaced by the word “concentrating” in the manuscript.

Point 3: Rewrite the sentence “ this event is closely related to the granitic magma activity during this interval, and the rare metal mineralization in the region is closely related to the peraluminous magmatic system” in line 46~48

Response 3: This sentence has been rewritten as “such large-scale rare-metal metallogenic event is closely related to the peraluminous granitic magma activities during this period”.

Point 4: The words “ barren dark materials” in line 56

Response 4: This statement means that these granites lack dark minerals. We realized that this expression is inappropriate here, and the sentence has been rewritten as “In particular, the granite group, which is composed of four exposed granites in the Xuebaoding area belongs to leucogranite and lacks dark minerals. Moreover weak alteration has been found in the contact zone between these granites and strata.”

Point 5: The word “structures” in line 61

Response 5: This is an inappropriate expression here, it has the same meaning as the word “structures” in Point 1 (referring to the the Wuzhutang granite and nearby ore bodies). This word has been replaced by the pronoun “them”.

Point 6: The word “alkali” in line 95

Response 6: We confirmed that the four granites are not belong to alkali granite. To avoid ambiguity, the word “alkali” has been deleted in the manuscript.

Point 7: Rewrite the sentence “To improve the accuracy with which the age of the Wuzhutang granite was constrained” in line 202

Response 7: This sentence has been rewritten as “To accurately constrain the crystallization age of the Wuzhutang granite”.

Point 8: The pronoun “They” in line 292

Response 8: The pronoun “They” in line 292 refers to the W-Sn-Be mineralization ages obtained from the eastern Zibaishan dome. The sentence “They mainly include...” has been rewritten as “Metallogenic ages obtained from the eastern Zibaishan dome are: ...”

Point 9: Rewrite the sentence “The magma sources of the three granites may contain similar metallogenic materials that originated from sedimentary strata with high tungsten contents, which is similar to the Shuangqiaoshan Formation in southern China”

Response 9: This sentence has been rewritten as “The source areas of the three granites may be mixed with some W-Sn-Be rich materials, e.g., a W-Sn-Be bearing metasedimentary strata that analogy to the Shuangqiaoshan Formation in southern China”.

Reply to Comments and Suggestions for Authors: The paper is well written although some grammar mistakes are here and there. The main issue is that the Wuzhutang granite without visible Eu negative anomalies. ASI is lower than 1.1. Do you believe it is a highly differentiated granite and related to rare metal mineralization? It has different Sr-Nd isotopic compositions from those of PLK and PK granites, so they can't be originated from the same metasedimentary rocks. It's more likely that the Wuzhutang granite has nothing to do with (predate) mineralization in this area and may contain more mantle component than PLK and PK or just has totally different magmatic source than PLK and PK.

Response: In general, except for PD01-H6, PD01-H7 and PD03-H4, the ASI values of samples of the Wuzhutang granite are close to 1.1. In other discrimination diagrams according to Wu et al., 2017, samples plotted into the region of highly differentiated granite. This paper believes that theWuzhutang granite has totally different Sr-Nd isotopic compositions from those of the Pankou and Pukouling granites, and they can't be originated from the same metasedimentary rocks. From the perspective of geological characteristics, the quartz vein type ore bodies mainly occur in the interior of the Wuzhutang granite or near the contact zone. Although the Wuzhutang granite share a deeper magmatic source from the the Pankou and Pukouling granites, there is no other evidence that the W-Sn-Be mineralization are unrelated to the Wuzhutang granite.

Reviewer 2 Report

The manuscript contains new geochronological, major and trace elements and isotopic data of granites with rare metal mineralization. The data are interesting and fill a gap among the sufficiently studied similar granites with rare metal mineralization. At the same time, the difference between the granites studied by the authors of the manuscript and those previously studied requires a new interpretation of the genesis of both granites and mineralization and is undoubtedly of interest to researchers involved in such topics.

I have several questions that are not clearly described:

1. In Figure 2. granite intrusions are shown as intrusive bodies that have sharp contact with host metamorphosed rocks. No contact metamorphism?

2. The host rocks are metamorphosed. What is the age of low-grade (e.g. greenschist facies?) metamorphism. Triassic? What is the relation of granitic magmatism to regional metamorphism?

3. Petrography of metasomatically altered granite is unclear. Please add the volume percent of rock-forming minerals.

4. How do authors interpret the Mesoproterozoic model age and source origin from the upper crust: remelting, mixing, etc.?

Nd model age of granitoids reflects the age of the continental crust (De Paolo, 1981; Patchett, 1992). In the other variant, the Nd model ages could result from the mixing of various sources and, correspondingly, do not provide direct information on the mechanisms of the sources could be the tectonic combination of complexes of various ages and geneses, the melting of sediments derived from various source.

5. Authors not fully referenced papers published on this topic.

Other remarks:

Line 19, 63, and others: How authors use “digenesis” This terminology is mainly used for sedimentary rocks, not for granites. I understand that sedimentary sources passed weathering and some elements

Line 55-56: I don’t understand well what is mean “leucogranites with weak alteration between strata and barren dark materials” Please explain.

Line 109: Dolomitic quartz veins. Maybe better to describe mineralogy of quartz veins

Line 114: mineralogy of granite is unusual: albite quartz and muscovite with very rare K-feldspar. Maybe granite is greisenized?

Line 116: If an alteration is weak better to show the petrography of granite

Line 117: what type of plagioclase (An ) and how much?

Line 238: monzogranite has a similar amount of K-feldspar and plagioclase

Line 244: all are plotted close to the line between K-calc-alkaline and medium K and in the TAS diagram are plotted in the field of normal granite and are slightly peraluminous.

Line 253: In Fig7 Eu negative anomaly is even not recognized, REE and trace element patterns significantly differ from Pankou and Pukouling granite but with similar enrichment in rare metals

Line 384: In Fig. 8 studied granites are looking as highly evolved I-type granite

Line 401: “Strongly reformed”? should be deformed

Line 450: F- rich are only two samples: H6 and H7

Comments for author File: Comments.pdf

Author Response

Reply to the Reviewer 2

Dear reviewer:

Point 1: In Figure 2. granite intrusions are shown as intrusive bodies that have sharp contact with host metamorphosed rocks. No contact metamorphism?

Response 1: In fact, weak contact metamorphism of muscovitization and fluorization were locally occurred in the contact zone in the country rocks.

Point 2: The host rocks are metamorphosed. What is the age of low-grade (e.g. greenschist facies?) metamorphism. Triassic? What is the relation of granitic magmatism to regional metamorphism?

Response 2: The low-grade metamorphism of greenschist facies was occurred during the Late Triassic in response to the intense shortening and thickening of the upper crust due to Indosinian orogeny. The regional metamorphism was occurred predate the granitic magmatism, as the granites are not deformed or metamorphosed.

Point 3: Petrography of metasomatically altered granite is unclear. Please add the volume percent of rock-forming minerals

Response 3: Figs. 3c,d,e show different degrees of greisenization, so we can’t accurately describe the volume percent of rock-forming minerals.

Point 4: How do authors interpret the Mesoproterozoic model age and source origin from upper crust: remelting, mixing, etc.?

Response 4: This paper does not pay much attention to the deep process of granite formation. This Mesoproterozoic model age implies a deeper source for the Wuzhutang grantie compared with the Pankou and Pukouling granites. In terms of its forming process, we favour the remelting model as there are no direct geological evidence that indicate magma mixing, e.g. the dark colored, microgranular and igneous-texture enclaves.

Other remarks

Point 5: Line 19, 63, and others: How authors use “digenesis” This terminology is mainly used for sedimentary rocks, not for granites. I understand that sedimentary sources passed weathering and some elements

Response 5: The word “digenesis” in line 19, 63 has been replaced by “magmatic”

Point 6: Line 55-56: I don’t understand well what is mean “leucogranites with weak alteration between strata and barren dark materials” Please explain.

Response 6: We realized that this expression is inappropriate here, and the sentence has been rewritten as “In particular, the granite group, which is composed of four exposed granites in the Xuebaoding area belongs to leucogranite and lacks dark minerals. Moreover, weak alteration has been found in the contact zone between these granites and strata.”

Point 7: Line 109: Dolomitic quartz veins. Maybe better to describe mineralogy of quartz veins

Response 7: This is a wrong expression here, what we really want to express is greisenization, as showed in Figs. 3 e,f. Moreover, it’s hard to accurately describe the volume percent of rock-forming minerals, as different degrees of greisenization were occurred.

Point 8: Line 114: mineralogy of granite is unusual: albite quartz and muscovite with very rare K-feldspar. Maybe granite is greisenized?

Response 8: The ore bodies mainly occur in the interior of the Wuzhutang granite or near the contact zone. Greisenization indeed occurred in the contact between ore bodies and the granite. We have redescribed the rock composition of monzogranite, and the inaccurate description has been rewritten as “The minerals in the granite mainly consist of muscovite (10~15 vol%), potassium feldspars (20~25 vol%), plagioclase (20~30 vol%), and quartz (40~45 vol%) (Fig. 3g).” In the revised manuscript, Fig. 3g has been replaced by a new sample photomicrograph that did not suffered alteration of greisenization.

Point 9: Line 116: If an alteration is weak better to show petrography of granite

Response 9: Fig. 3c,d,e has shown greisenization occurred at interior and edge of the sample of the Wuzhutang granite.

Point 10: Line 117: what type of plagioclase (An ) and how much?

Response 10: We have not performed in situ analysis of plagioclase mineral crystals, while according to CIPW standard mineral calculation, the An value of plagioclase is in range of 17~23%, and the content is about 25~33% (12 samples).

Point 11: Line 238: monzogranite has a similar amount of K-feldspar and plagioclase

Response 11: According to CIPW standard mineral calculation of 12 samples, the contents of K-feldspar and plagioclase are 19~22 % and 25~33 %, respectively.

Point 12: Line 244: all are plotted close to the line between K-calc-alkaline and medium K and in the TAS diagram are plotted in the field of normal granite and are slightly peraluminous

Response 12: We have noticed this phenomenon, while according to Wu et al., 2017, the Wuzhutang granite belongs to peraluminous series.

Point 13: Line 253: In Fig 7. Eu negative anomaly is even not recognized, REE and trace element patterns significantly differ from Pankou and Pukouling granite but with similar enrichment in rare metals

Response 13: We have noticed both of these phenomena, and it is because of its high rare metal contents that we think it may be the parental rock for those ore veins.

Point 14: Line 384: In Fig. 8. studied granites are looking as highly evolved I-type granite

Response 14: The Wuzhutang granite indeed has I-type properties, and according to Wu et al., 2017, it belongs to highly differentiated granite. However, it shares a lower degree of differentiation than the Pankou and Pukouling granites.

Point 15: Line 401: “Strongly reformed”? should be deformed

Response 15: The main deformation of the SGOB was occurred at Late Triassic, and it was reworked during Cenozoic Himalayan orogeny, so we use the “reformed”.

Point 16: Line 450: F- rich are only two samples: H6 and H7

Response 16: It is indeed that only two out of twelve samples from the Wuzhutang granite contains high F concentrations, which is lower than the Pankou and Pukouling granite. This could be the reason why the scale and extension of mineralization and the particle size of the rare metal minerals in the eastern part of the dome are larger than those in the western part.

Reviewer 3 Report

The Xuebaoding W-Sn-Be deposit is known for producing large, colorful, euhedral crystals of scheelite, cassiterite, and this study is hot topic one, so it is useful for researcher to cite. Just a few mistakes need to be corrected, then put ahead publishing.

Comments for author File: Comments.pdf

Author Response

Reply to the Reviewer 3

Dear reviewer:

I would like to express my great appreciation to you for your constructive suggestions. My responses for your questions are as follows:

Point 1: Line 8: there is no second affiliation at authors line.

Response 1: We've added new affiliation at authors line.

Point 2: Line 12~15: These sentences belong to the introduction and can be deleted here “Previous research data are mainly sourced from the Pukouling and Pankou granites of the eastern side of the Zibaishan dome. However, the magmatic and metallogenic ages of the Wuzhutang granite and nearby ore bodies on the western side of the dome have not been determined, and petrological and mineralogical studies of these structures have not been performed.”

Response 2: As you suggested, we have deleted these sentences.

Point 3: Line 28, the word “Although”

Response 3: The word “Although” has been replaced by “We think”

Point 4: Line 89: In text body. Fig.1 refers to [1, 47-49], at here why not unify

Response 4: This error has been corrected.

Point 5: Line 225~226: Fig. 5 caption is not suitable. In fact, it is shows the LA-MC-ICPMS dating of cassiterite yields a concordant age.

Response 5: The caption is rewrite as “Figure 5. LA-MC-ICPMS cassiterite U-Pb age of the beryl, cassiterite, and scheelite bearing quartz vein in the Wuzhutang granite from the Xuebaoding mining area, Sichuan Province, China”

Point 6: Line 269: insert (a) (b) at figure caption.

Response 6: We have insert (a) (b) at this figure caption.

Point 7: Line 463: title number is 7

Response 7: We have add the title number.

Point 8: Line 468: add (3) The relationship between W-Sn-Be mineralization and highly fractionated granite......

Response 8: We have add the conclusion (3): The W-Sn-Be mineralization within the Zibaishan dome has closet genetic relationship with these highly fractionated granites.

Point 9: Line 482: Please check the rules for author number for minerals journal. I remeber list all authors name, instead of three persons and et al.

Response 8: We have contacted the editors and confirmed that this format is acceptable.

Author Response File: Author Response.docx

Reviewer 4 Report

RE: Genesis of the Wuzhutang Granite and Associated W-Sn-Be 2 Mineralization in the Xuebaoding Mining Area, Sichuan Province, China

In this paper, the authors (Dia et al.) have attempted to determine Genesis of the Wuzhutang Granite and Associated W-Sn-Be 2 Mineralization in the Xuebaoding Mining Area, Sichuan Province, in western China. In this way, they seem to have done very well. This article is very well prepared and organized and has a high quality in terms of content. I find this article acceptable in the Journal (Minerals). The only problem is the low quality of the some figures that need to be prepared with high quality and replaced in the article.

Author Response

Dear reviewer:

I would like to express my great appreciation to you for your constructive suggestions. My responses for your questions are as follows:

Point 1: In this paper, the authors (Dia et al.) have attempted to determine Genesis of the Wuzhutang Granite and Associated W-Sn-Be 2 Mineralization in the Xuebaoding Mining Area, Sichuan Province, in western China. In this way, they seem to have done very well. This article is very well prepared and organized and has a high quality in terms of content. I find this article acceptable in the Journal (Minerals). The only problem is the low quality of the some figures that need to be prepared with high quality and replaced in the article.

Response 1: As you suggested, these low quality figures are all replaced by high-resolution ones. In addition, we also provide a PDF version for editing.