# Talk:Aucanquilcha

The following copied from my talk page for access by others. Vsmith (talk) 16:32, 10 September 2015 (UTC)
In response to a request for a copyedit at WP:WikiProject Guild of Copy Editors/Requests, I began to read and copyedit Aucanquilcha. I'm always happy to read about another volcano. I made a number of minor edits to improve the prose. Then I noticed that, while the beginning of the article was full of grammatical errors, the further I got into the article the better the writing became until there were no errors. Then, suddenly, there would be a few sentences with a lot of basic errors in them, and then the perfect prose returned. For the first few sections, I read every word (trying to learn something). After a while, I realized that the prose was so detailed and so quasi-technical that it might have come directly from a geology textbook and I stopped reading. I don't know whether this editor wrote the entire article and just had some lapses in grammar here and there, or just wrote a few sentences himself/herself and copied the rest from a textbook. I'm not sure, but maybe parts are too detailed and too technical for a Wikipedia article. Also, if parts are copied, that's not good, either.
Also, I noticed several times references to different periods, but with no link and no explanation, as if the reader is supposed to know what these periods are.
Finally, (and this is minor compared to the possibly bigger issues I raised above), I tried to find an article to link to for "arc magma". Should it be to the article Volcanic arc? Even in that article, however, I didn't see much specifically about "arc magma". Over to you. Have fun. Corinne (talk) 02:26, 8 September 2015 (UTC)

I've checked the Geology ref (#4) and see no reason for concern re: copying. I don't have ready access to most of the others. Will read through it closer for other problem stuff as time permits, the "arc magma" could be linked to Continental arc. Vsmith (talk) 20:26, 8 September 2015 (UTC)
O.K. Thanks for reading the article. I've got to make sure you get credit as a copy-editor. I was just looking at your edits. In the sentence in which you added a link at "scoria" – [1], what does this sentence mean? Is there a word missing?
Cerro Alconcha's lavas and scoria overly Tuco.
- Corinne (talk) 00:07, 9 September 2015 (UTC)
That section needs work, but I can only  - so far - access the abstract for the ref. It would seem the lava and scoria are found on top of the Tuco volcanics ... but I'm currently confused about the "Tuco" or "Toco" volcano as I don't find the names on the map. There is a Cerro Toco, but it is to the southeast quite a distance. The link you provided above was fun... :) Vsmith (talk) 02:09, 9 September 2015 (UTC)
Corinne Being the editor who expanded the article, I should comment here. I know that copying stuff - or even closely paraphrasing it - is not OK copyright-wise (as well as plagiarism-wise) and thus did all stuff in my own voice. That said, when I am writing large amounts of text without copying, my spelling and grammar tends to slip rather rapidly. The Toco/Tuco thing was a typo; I've fixed it. Jo-Jo Eumerus (talk, contributions) 12:19, 9 September 2015 (UTC)
Thanks for fixing that Toco typo, the map in the article doesn't show it or some of the other volcanic features mentioned - so the "Aucanquilcha cluster" section is a bit confusing. Vsmith (talk) 01:26, 10 September 2015 (UTC)
I just saw that User:GeoWriter reverted my edit at Aucanquilcha [2] in which I had changed "erupted" to "erupting". I don't understand how "Erupted after a probable 2 mya hiatus,..." can be grammatically correct. "Having erupted", perhaps, but not "Erupted". "Erupting after a...2 mya hiatus,..." is a participial phrase. Perhaps "Erupted after..." is volcanologist jargon. Could someone explain how this construction could be correct? Corinne (talk) 15:03, 10 September 2015 (UTC)
Changed to "Having erupted..." per your suggestion. Vsmith (talk) 15:17, 10 September 2015 (UTC)
Hey, geology guys, at the risk of annoying you, I have to explain why "Erupting" is correct in this sentence. "Having erupted" would be correct if the verb in the main clause that follows it were in past tense, but it isn't in past tense. It's in present tense ("is"), so "Erupting" is correct. Compare:
Having erupted after a probable 2 mya hiatus, the 6–4 mya Gordo group continued to erupt for another 200 years. [hypothetical example to illustrate verb tenses; the past form of the participial phrase, "having erupted" means that the volcano group erupted before it "continued to erupt". It doesn't matter what the second verb is. What matters is that it's in past tense.]
Erupting after a probable 2 mya hiatus, the 6–4 mya Gordo group is located...
The participle "erupting" does not mean that the volcanoes in the group are erupting now. However, I do think it would improve the clarity of the sentence if the time when the volcanoes last erupted were mentioned after "Erupting":
Erupting X million years ago after a probable 2-million-year hiatus, ...
By the way, as you can see, I just changed "after a probable 2 mya hiatus" to "after a probable 2-million-year hiatus". Doesn't "mya" mean "million years ago"? If so, that phrase does not make sense, as you can see here: "after a probable 2 million-year-ago hiatus". Corinne (talk) 15:55, 10 September 2015 (UTC) I mean, it does not make sense if the hiatus itself was of 2 million years' duration. If you mean that the hiatus was 2 million years ago, then it needs to be re-worded as: "after a probable hiatus 2 million years ago". Corinne (talk) 15:58, 10 September 2015 (UTC)
 Yeah, "mya" means "million years ago". According to the source, it is a 2 million year gap between two phases of eruptive activity. Jo-Jo Eumerus (talk, contributions) 15:59, 10 September 2015 (UTC)
Possible redo - current: Erupting after a probable 2-million-year hiatus, the 6–4 mya Gordo group is located... maybe change the order to: The Gordo group, which erupted 6–4 mya following a probable 2-million-year hiatus, is located... as the Erupting... bit may be read as is currently erupting. Vsmith (talk) 16:21, 10 September 2015 (UTC)
That latter version is good, Vsmith. I don't know why I didn't think of it myself. What do others think? Corinne (talk) 16:47, 10 September 2015 (UTC)
That seems fine for me.Jo-Jo Eumerus (talk, contributions) 16:49, 10 September 2015 (UTC)
I also prefer Vsmith's suggestion of The Gordo group, which erupted 6–4 mya following a probable 2-million-year hiatus, is located... but with one additional change - capitalise group to Group if it is an official local stratigraphic name of the rock unit in question. Perhaps Jo-Jo Eumerus can confirm this from references.
It's probably just water under the bridge now, but for the record, my thinking with "erupting/erupted" was along the lines of: would we write e.g. "Building after 9 years of independence from Britain, the White House is located in Washington DC" or "Built after 9 years of independence from Britain, the White House is located in Washington DC"? I'd write the latter. GeoWriter (talk) 19:56, 10 September 2015 (UTC)

"Group" is the term I used to distinguish the volcanoes that are part of the Aucanquilcha complex from those that form the various stages in which Aucanquilcha was built. The system is a compound volcano surrounded by older volcanoes which are part of a volcanic group, from what I got in the source.Jo-Jo Eumerus (talk, contributions) 20:04, 10 September 2015 (UTC)
In that case, I suggest this is clarified by changing The Aucanquilcha cluster formed in four stages, each corresponding to a group. to  The Aucanquilcha cluster formed in four stages, each corresponding to a group of volcanoes. (or volcanic landforms/structures/edifices or some other appropriate descriptor), to clarify that you are not referring to a stratigraphic group. GeoWriter (talk) 20:18, 10 September 2015 (UTC)
Made the change w/out the capital G on group. Not clear whether the Gordo group (and others) are formal names or an informal tag referring to local volcano clusters? Vsmith (talk) 20:22, 10 September 2015 (UTC)
They are an informal name in the group, from checking the source. I've also changed a few sentences; two because they weren't relaying information correctly, two others because they resembled the source too much for my liking.Jo-Jo Eumerus (talk, contributions) 20:41, 10 September 2015 (UTC)
GeoWriter Regarding your examples above using the verb build, the difference between "Erupting X years ago, the Gordo group..." and your examples with build is that to erupt is an intransitive verb and to build is a transitive verb. Build requires an object, which explains why your first example doesn't work. When a sentence begins with a participial phrase, the person (or thing) doing that action must come right after the participial phrase. Since a house cannot build, that example doesn't work. However, it does work when you use the past participle: "Built after 9 years of independence from Britain, the White House is located in Washington DC" because the phrase is really a shortened form of "The White House was built after 9 years of independence from Britain." The present participle "erupting" does work, though, because it was the Gordo group of volcanoes that were erupting.
Jo-Jo Eumerus I was looking at your most recent edits. I'm puzzled why you would change "overlie Tuco" to "lie on top of Tuco" since that's what "overlie Tuco" means. If you don't like "overlie", perhaps you'd like "cover Tuco". Also, here is the sentence with your next edit as it is now:
Cerro Gordo itself (5.49 mya) has a in the cluster, and its crater is breached westwards, exposing about twelve radial dykes but with no trace of a debris avalanche.
It clearly needs some work, but since I don't know what you intended, I'll leave it to you. Corinne (talk) 21:55, 10 September 2015 (UTC)
 Argh. I've added in a missing word. As for the other change, they mean the same thing but the previous text was too similar to the source - excessive similarity in wording between an article and its sources can be a copyright issue.Jo-Jo Eumerus (talk, contributions) 22:11, 10 September 2015 (UTC)
Oh. Thanks for explaining. Corinne (talk) 01:16, 11 September 2015 (UTC)
I think my misunderstanding of erupted/erupting in the sentence under discussion stems from the following sources:
(a) the fact that to erupt can be a transitive or intransitive verb (according to the OED)
and
(b) the geological ambiguity (for me) of the word group.
I thought that the Gordo group was a set of lava flows that had been erupted by the volcano. I think the transitive past participle erupted would have worked for that meaning of group. Jo-Jo Eumerus has now clarified that the sentence was about a group of volcanoes. I agree that his meaning of group should have used the intransitive present participle erupting. I apologise for picking the wrong meaning of the word group.  GeoWriter (talk) 14:04, 11 September 2015 (UTC)
GeoWriter There's no need to apologize. This is a complicated subject. I've learned something from you. I had never seen erupt used as a transitive verb and didn't know it could be used transitively. Corinne (talk) 15:26, 11 September 2015 (UTC)

Jo-Jo Eumerus I saw your recent edits, including one to this sentence in which you changed "found" to "located":

Other sulfur mines in 1977 were located between Cerro Polan and Cerro Gordo and south of the main Aucanquilcha massif.
First, the prepositional phrase "in 1977" is in the wrong place. Second, the verb "located" can mean several things: "found", "situated", and "placed". I assume you thought "found" was not the right verb. That leaves two meanings. I think it would sound more like "situated" if you removed (or moved) "in 1977". When you give a date like that, it suggests that something specific happened (either "found" or "placed") in that year. What was the reason for including "in 1977"? What happened then? If you mean that in 1977 "other sulfur mines" were established, then you might think about changing the verb from "located" to "established".
Third, you have "other sulfur mines" (plural) in this sentence, but the sentences immediately following it refer to "the mine" (singular). This ought to be cleared up. Corinne (talk) 00:17, 19 September 2015 (UTC)

"Located" as used here is perhaps a bit of exploration geology jargon and, in my experience, is used when a mining claim is surveyed and staked with a claim monument on the ground as a prelude to further work leading to a potential mine development. To avoid this "jargon" the sentence could be reworded as: In 1977 other sulfur mines were established between Cerro Polan and Cerro Gordo and south of the main Aucanquilcha massif. Vsmith (talk) 01:20, 19 September 2015 (UTC)
Oh... Another meaning of "located". Thanks for explaining. Corinne (talk) 01:33, 19 September 2015 (UTC)
On rereading, and looking at the map, it seems: "In 1977 other sulfur mines were present between Cerro Polan and Cerro Gordo and south of the main Aucanquilcha massif." would work as these "other mines" were at a different location to the west. Vsmith (talk) 02:04, 19 September 2015 (UTC)
I'll leave it to either you or Jo-Jo Eumerus to make any change there. Vsmith, I just looked at the lead image in the article. What are those pointy rocks all over the place in the foreground? Corinne (talk) 02:35, 19 September 2015 (UTC)
Them "pointy rocks" be bushes, look at the image file :) Vsmith (talk) 02:44, 19 September 2015 (UTC)
The last paragraph in the section starts with: "A sulfide mineral close in composition to Cu5FeS6 (idaite), together with native sulfur and covellite was described in 2000." I can't access the reference given, but I don't see the relevance of that sentence to the article. The mineral idaite is described as a breakdown product of bornite and a supergene mineral according to Mindat. How is that factoid relevant. The presence of covellite suggests supergene enrichment. Vsmith (talk) 03:27, 19 September 2015 (UTC)

I have myself some doubts about that. Now that you put it this way, I would not mind seeing it removed - it probably is not overly relevant.Jo-Jo Eumerus (talk, contributions) 08:19, 19 September 2015 (UTC)
Done. Vsmith (talk) 14:09, 19 September 2015 (UTC)

I've waited for most changes to the article to be made before going through it once more to look for any errors or unclear sentences. I will leave questions and concerns here. I'll leave a few this evening and then continue reading tomorrow.
1) In the lead, it starts out by saying Aucanquilcha is a massive stratovolcano. In the next sentence we ready that it is a ridge...composed of a complex of stratovolcanoes: 

a ridge 6,176 metres (20,262 ft) high composed of a complex of stratovolcanoes that is embedded in a larger cluster of volcanoes known as the Aucanquilcha cluster.
Already, the reader will be scratching his head. Is Aucanquilcha a stratovolcano or a ridge composed of stratovolcanoes? 
The next sentence starts, "At Aucanquilcha volcano". The subject of the next sentence is "the cluster of volcanoes". The next sentence mentions: "both the principal Aucanquilcha complex and the other volcanoes of the cluster". I think you are introducing too many different terms in this paragraph, and it jumps around too much (probably because it is summary of the rest of the article), and it will end up confusing the reader. I'm sure you know what you mean by "the principal Aucanquilcha complex" and "the other volcanoes of the cluster", but to the average reader who is already confused, this will hopelessly confuse him. I would reduce the number of terms you introduce in the lead (or at east the first paragraph), and try to organize them in a way that makes sense, such as smaller unit to larger, or larger unit to smaller. You can explain the "complexes" later. 
2) You mention fumarolic activity and sulfur deposits in the middle of the first paragraph. Then you say more about the sulfur in the second paragraph. I think all information about sulfur deposits and mining should be kept together.
3) I'm wondering whether you might have too many details about the sulfur mining in the second paragraph of the lead. 
4) In the first paragraph of Aucanquilcha#Regional setting you have cubic kilometres per millenium, and then in parentheses cubic miles per Gs. What is "Gs"? 
5) In the second paragraph, what is "partial melts"? Can you either explain this phrase or link it to an article that would explain it?
6) At the beginning of the third paragraph is the following sentence:

The long-term magma output of Aucanquilcha is comparable to the magma output of local long-term active volcanoes such as Ollagüe and Llullaillaco.
For a non-expert, the word "local" doesn't mean much. What does it mean? Would it be possible to substitute a more ordinary word such as "nearby"? 
7) In the next sentence, we ready "an early peak is followed by later...activity". For the non-expert, could you explain what "an early peak" means? Is this (a) early in the development of a volcano or (b) early in a particular eruption, or something else? If this is made clear, I think "is followed by later...activity" will also make more sense. (Followed immediately? Followed years, decades, centuries, or millennia later? I see "per millennium" there, but still, for a non-expert, there will be some guessing here at the word "later".)
– Well, that's all for now. – Corinne (talk) 03:22, 6 October 2015 (UTC)
8) I've pretty much finished. There is one paragraph that maybe could be improved. It is the last paragraph in Aucanquilcha#Local setting. I'll copy it here, and number the sentences, for ease of discussion:

(1) Various parts of the main volcano have been subjected to hydrothermal alteration. (2) The Azufrera stage edifice was subject to the most alteration; especially in the summit area and between the Angulo and Azufrera summits lie sulfur rich talus deposits. (3) Sulfur deposits are also found on the Angulo summit. (4) The central part of the complex is heavily altered by fumarole activity. (5) Hydrothermal alteration may be driven by the formation of a deep magma reservoir and resulting hydrothermal circulation in overlying rocks.
I think the paragraph is a bit choppy, not cohesive, and perhaps a bit repetitive. 
(a) The first two sentences are all right. Toward the end of the second sentence you say:

especially in the summit area and between the Angulo and Azufrera summits lie sulfur rich talus deposits.
and then the third sentence says:

Sulfur deposits are also found on the Angulo summit.
Is it really necessary to keep these as separate sentences? Couldn't they be combined?
(b) The fourth sentence reads:

The central part of the complex is heavily altered by fumarole activity.
i. This is the third time in the paragraph we see a form of "alter". First, "hydrothermal alteration", then "subject to the most alteration", now "heavily altered", and in the next sentence, "hydrothermal alteration" again. It would be good if these could be reduced by one or two.
ii. Is "fumarole activity" (fourth sentence) really different from "hydrothermal alteration"? Is it an example of a type of hydrothermal activity? The paragraph can be improved, and one of the changes would depend upon the relationship between "fumarole activity" and "hydrothermal alteration".
iii. Also, is "the central part of the complex" the same area as "the summit area and between the Angulo and Azufrera summits" (second sentence)? If so, that's another place the sentences could be consolidated, reducing unnecessary repetition. If you cannot, or don't feel like, re-arranging things, if you will answer my questions, above, I'll do the re-arranging. Corinne (talk) 17:57, 6 October 2015 (UTC)

Thanks for applying some GOCE magic to this article, Corinne. I'll answer your questions/concerns tomorrow.Jo-Jo Eumerus (talk, contributions) 18:50, 6 October 2015 (UTC)
Save for #3 (will need to think about this), #4 (artifact of my use of the {{convert}} template; I'll see if there is a way to prevent it from converting years in gigaseconds) and 8# I think I got everything. I'll give these another pass.Jo-Jo Eumerus (talk, contributions) 18:42, 7 October 2015 (UTC)

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