Tutupaca is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so. | ||||||||||
This article appeared on Wikipedia's Main Page as Today's featured article on July 16, 2019. | ||||||||||
| ||||||||||
A fact from this article appeared on Wikipedia's
Main Page in the "
Did you know?" column on
August 19, 2015. |
This article is rated FA-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||||||||||||||||||||||||
|
The following references may be useful when improving this article in the future: |
I've done a bit of copyediting, but need to understand things a bit better to be sure I don't screw anything up.
The occurrence of trachyandesite and trachyte has also been described. The volcanic rocks erupted during the Holocene define a potassium-rich calc-alkaline suite.I can see the first source but not the second; it looks as if both these are general statements about the overall volcano, and don't refer specifically to the older complex or newer peaks. Is that correct? If so I think this paragraph should be organized so the reader can see the distinction -- from the general to the specific, if possible.
the origin of a 6–8 kilometres (3.7–5.0 mi) long avalanche deposit: should this be "debris avalanche deposit"? Perhaps this is implied in geology, but for the general reader it's as well to avoid misinterpretations caused by ignorance.
The total surface area covered by the collapse is about 12–13 kilometres (7.5–8.1 mi), the pyroclastic flow reached both Lake Suches north of the volcano and the Callazas River east of it: I don't see the connection between the two halves of this sentence. This is the Paipatja pyroclastic flow we're talking about? Was this flow associated with the collapse? I understood the flow to be a pre-existing formation that was overrun by the debris avalanche. If so, the extent of the flow and the extent of the avalanche are unconnected. (After a bit of Googling): it appears an older version of this article says the sequence was a pyroclastic flow named Suri Phuju, then the debris avalanche, then the Paipatja pyroclastic flow, which overlays the debris. If that's correct I don't think we should be saying that the flow divides the units.
one unit featuring 100–200 metres (330–660 ft) long hummock-like hills like other avalanches from volcanoes: we say "like other avalanches from volcanoes", but then apparently the ridges have also been observed in other collapse deposits. Are these hummock-like hills the more usual form for a long debris avalanche?
Pausing there for now to review these points. Mike Christie ( talk - contribs - library) 01:51, 11 March 2018 (UTC)
Shortly before the collapse[e], a pyroclastic flow was erupted from the volcanowith the note under [e] saying
Stratigraphic relations imply that this pyroclastic flow pre-dates the main collapse, but radiocarbon dating does not have a sufficient resolution to separate the two events in time.) and then another pyroclastic flow - Paipatja - during the collapse. I had some difficulty at finding the correct flow for this sentence; I've rewritten it but I am not sure if it's much better now.
The deposit is mostly confined within glacial valleys and is subdivided into two units which are separated from each other by the Paipatja pyroclastic flow. The Paipatja pyroclastic flow reached both Laguna Suchez north of the volcano and the Callazas River east of itas "The deposit is mostly confined within glacial valleys and is overlaid by the Paipatja pyroclastic flow which divides the debris into two units. The pyroclastic flow reaches both Laguna Suchez north of the volcano and the Callazas River east of it." This gives it as structure (present tense) rather than events (past tense); the events narrative can be saved for the eruptive history section. Mike Christie ( talk - contribs - library) 22:59, 14 March 2018 (UTC)
The occurrence of trachyandesite and trachyte has also been described, and I see the source cites it to "De La Cruz, N. & De La Cruz, O.: Memoria explicativa de la revisión geológica del cuadrángulo de Tarata (35-v), informe inédito. Lima. Instituto Geológico Minero y Metalúrgico, (2001), 19 p." Would it be worth trying to get hold of this, e.g. via WP:RX? Pauccara and Matsuda say "The Tutupaca volcano consists of an alternating sequence of pumice pyroclastic flows and ash with massive blocks. It is followed by an important sequence of andesitic and trachytic lavas flows, and finally a trachyandesitics debris flow tuff with abundant hornblende crystals containing, biotite, pyroxene and quartz." Do you think the original source would have more details?
The volcanic rocks erupted during the Holocene define a potassium-rich calc-alkaline suite. Dacites from eastern Tutupaca contain amphibole, apatite, biotite, clinopyroxene, iron-titanium oxides, orthopyroxene, plagioclase, quartz and sphene.You say above that Samaniego 2015 is only talking about Holocene eruption products, so how about joining these two sentences so it's clear that applies to the second one? I know we said earlier that only eastern Tutupaca is Holocene, but we could remind the reader at this point: "The Holocene-era eruption products of eastern Tutupaca define a potassium-rich calc-alkaline suite, and its dacites contain amphibole, apatite, biotite, clinopyroxene, iron-titanium oxides, orthopyroxene, plagioclase, quartz and sphene."
More tonight. Mike Christie ( talk - contribs - library) 11:07, 14 March 2018 (UTC)
Based on 30 whole-rock major and trace element analyses, the Holocene eruptive products of Tutupaca volcano are classified as high-K calc-alkaline dacites (Fig.9). All samples from the Eastern Tutupaca domes display a very restricted dacitic compositionand so on with the exxact minerals later. I am not sure if there is any significance to the fact that Samaniego 2015 differentiates here between "Holocene eruptive products of Tutupaca volcano" and "Eastern Tutupaca domes".
-- Mike Christie ( talk - contribs - library) 23:27, 16 March 2018 (UTC)
Off the coast of Peru, the Nazca Plate subducts at 5–6 centimetres per year (2.0–2.4 in/year) beneath the South America Plate.[24][10] This subduction process is responsible for the volcanism in the Central Volcanic Zone[c] of the Andes, which includes the volcanoes of Peru's Western Cordillera.[24] (The Central Volcanic Zone is one of four volcanic belts in the Andes, together with the Northern Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone.[25]) Aside from Tutupaca, Peru also features the volcanoes Sara Sara, Solimana, Coropuna, Andagua volcanic field, Ampato-Sabancaya, Chachani, El Misti, Ubinas, Huaynaputina, Ticsani, Yucamane and Casiri.[10] Major historical eruptions happened at El Misti 2,000 years ago and at Huaynaputina in 1600.[24]I'd like to change this to: "Off the coast of Peru, the Nazca Plate subducts at 5–6 centimetres per year (2.0–2.4 in/year) beneath the South America Plate, causing volcanism in three of the four volcanic belts in the Andes, including the Central Volcanic Zone, where Tutupaca is located. Other Peruvian volcanos include Sara Sara, Solimana, Coropuna, Andagua volcanic field, Ampato-Sabancaya, Chachani, Ubinas, Ticsani, Yucamane, and Casiri. Major eruptions have occurred at El Misti, 2,000 years ago, and at Huaynaputina, in 1600." (After the mention of the CVZ, put a note with what's currently in parentheses.) This is enough of a rework that I wanted to check it with you. Also, we list Peruvian volcanoes, but the CVZ includes Chilean volcanoes too, doesn't it? Any reason to include these specifically? Does the list of other volcanoes add to the reader's understanding? Mike Christie ( talk - contribs - library) 15:19, 17 March 2018 (UTC)
Tutupaca is about 700,000 years old.[29] The older complex was active at first with lava flows and then with a major explosive eruption,[3] all of which took place over 25,000 years before present.: It seems a little odd to say that the volcano is about 700 ky old, and then say it's "first" activity was over 25,000 years ago. I see Scandiffio et al says "The age of Tutupaca volcano is estimated around 0.7 M.a", but I can't see Samaniego et al.; what does it say exactly?
their occurrence is supported by radiocarbon dating of eruption products: Do Samaniego and Valderrama directly contradict each other re whether these are Tutupaca or Yucamane eruptions? If not I think we can combine these sentences and shorten things.
218 ± 14 years before present[20], probably in 1802: this is inconsistent, isn't it? 1950 - 218 = 1732. If "present" means "date of the paper" I would make it either "152 ± 14 years before present" with the link to BP, or "1798 ± 14 years", to avoid tying the estimate to the date of the paper.
-- Mike Christie ( talk - contribs - library) 22:33, 17 March 2018 (UTC)
. These moraines are probably formed during the Last Glacial Maximum (LGM), which has been broadly dated at 17–25 ka in the Western Cordillera of the Peruvian Andes (Smith et al. 2008; Bromley et al. 2009)... This ignimbrite deposit is covered by the LGM moraines, suggesting an age older than 25 ka.
esults of this calibration procedure show that the five samples are statistically identical at a 95 % confidence level with a pooled mean of 218±14 aBP. The calibrated calendar age for this average 14C age yields two age spans, the most important being 1731–1802 cal AD period (with a relative area of 85 %). We emphasise that the two historic eruptions (1787–89 and 1802 AD) reported by Zamácola y Jaúregui (1804) and Valdivia (1847) fall at the end of this period.. This is just odd. BTW, the reason why the collapse is linked to the 1802 eruption is because historical reports indicate that the 1802 eruption was stronger than the 1787-1789 one.
Given the conversation above, here's a possible rewrite for the 1802 section and the paragraph just above it.
The [note] would say something like "The uncalibrated radiocarbon age of the samples is 218±14 years before present, with 95% confidence; the calibrated age consists of two ranges, with an 85% probability that the date lies between 1731 and 1802."
I changed "radiocarbon dating of eruption productions" to just "radiocarbon dating" since it seems impossible that the actual eruption products could have been dated. I included your note about why the 1802 eruption is thought to be associated with the collapse; I don't know which source that comes from. How does it look? Mike Christie ( talk - contribs - library) 13:40, 18 March 2018 (UTC)
There are reports of eruptions in 1780, 1787, 1802, 1862 and 1902 which are supported by radiocarbon dating of eruption products.sounds like we are saying that radiocarbon dating supports the existence of each eruption, which is not correct. Sourcing the "now believed to be at Tutupaca" is dicey, I'd probably use the GVP citation, the impression I have is that this is the now accepted consensus not just Samaniego's opinion.
and is thought to be associated with the 1802 eruption since historical reports indicate it was stronger than the 1787-1789 eruption., that is logical inference but Samaniego 2015 does not explicitly give this thought process. Other than these points I like the rewrite. Jo-Jo Eumerus ( talk, contributions) 14:26, 18 March 2018 (UTC)
Here's another draft that tries to take those points into account:
-- Mike Christie ( talk - contribs - library) 23:54, 19 March 2018 (UTC)
Some authors believed that Yucamane volcano was a more likely source for these eruptions, but Samaniego et al. (2015) showed that Yucumane last erupted 3,000 years ago, and the other eruptions, in particular those of 1787-1789 and 1802, most likely occurred at Tutupaca.with "and the other eruptions, in particular those of 1787-1789 and 1802, most likely occurred at Tutupaca." sourced to the GVP article on Tutupaca. Jo-Jo Eumerus ( talk, contributions) 09:40, 20 March 2018 (UTC)
I copyedited the lead; does that look OK? Can you add any more details from the body? I think this is about ready to nominate. I'd like to read it through one more time, probably tomorrow, to see if I can spot anything else, but it's more or less there. Mike Christie ( talk - contribs - library) 02:36, 21 March 2018 (UTC)
Two more points.
Other than that I think this is ready to go once you hear from Ceranthor. Mike Christie ( talk - contribs - library) 10:02, 21 March 2018 (UTC)
Sorry for my delay, real life's been a bitch lately! ceran thor 02:38, 27 March 2018 (UTC)
Tutupaca is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so. | ||||||||||
This article appeared on Wikipedia's Main Page as Today's featured article on July 16, 2019. | ||||||||||
| ||||||||||
A fact from this article appeared on Wikipedia's
Main Page in the "
Did you know?" column on
August 19, 2015. |
This article is rated FA-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||||||||||||||||||||||||
|
The following references may be useful when improving this article in the future: |
I've done a bit of copyediting, but need to understand things a bit better to be sure I don't screw anything up.
The occurrence of trachyandesite and trachyte has also been described. The volcanic rocks erupted during the Holocene define a potassium-rich calc-alkaline suite.I can see the first source but not the second; it looks as if both these are general statements about the overall volcano, and don't refer specifically to the older complex or newer peaks. Is that correct? If so I think this paragraph should be organized so the reader can see the distinction -- from the general to the specific, if possible.
the origin of a 6–8 kilometres (3.7–5.0 mi) long avalanche deposit: should this be "debris avalanche deposit"? Perhaps this is implied in geology, but for the general reader it's as well to avoid misinterpretations caused by ignorance.
The total surface area covered by the collapse is about 12–13 kilometres (7.5–8.1 mi), the pyroclastic flow reached both Lake Suches north of the volcano and the Callazas River east of it: I don't see the connection between the two halves of this sentence. This is the Paipatja pyroclastic flow we're talking about? Was this flow associated with the collapse? I understood the flow to be a pre-existing formation that was overrun by the debris avalanche. If so, the extent of the flow and the extent of the avalanche are unconnected. (After a bit of Googling): it appears an older version of this article says the sequence was a pyroclastic flow named Suri Phuju, then the debris avalanche, then the Paipatja pyroclastic flow, which overlays the debris. If that's correct I don't think we should be saying that the flow divides the units.
one unit featuring 100–200 metres (330–660 ft) long hummock-like hills like other avalanches from volcanoes: we say "like other avalanches from volcanoes", but then apparently the ridges have also been observed in other collapse deposits. Are these hummock-like hills the more usual form for a long debris avalanche?
Pausing there for now to review these points. Mike Christie ( talk - contribs - library) 01:51, 11 March 2018 (UTC)
Shortly before the collapse[e], a pyroclastic flow was erupted from the volcanowith the note under [e] saying
Stratigraphic relations imply that this pyroclastic flow pre-dates the main collapse, but radiocarbon dating does not have a sufficient resolution to separate the two events in time.) and then another pyroclastic flow - Paipatja - during the collapse. I had some difficulty at finding the correct flow for this sentence; I've rewritten it but I am not sure if it's much better now.
The deposit is mostly confined within glacial valleys and is subdivided into two units which are separated from each other by the Paipatja pyroclastic flow. The Paipatja pyroclastic flow reached both Laguna Suchez north of the volcano and the Callazas River east of itas "The deposit is mostly confined within glacial valleys and is overlaid by the Paipatja pyroclastic flow which divides the debris into two units. The pyroclastic flow reaches both Laguna Suchez north of the volcano and the Callazas River east of it." This gives it as structure (present tense) rather than events (past tense); the events narrative can be saved for the eruptive history section. Mike Christie ( talk - contribs - library) 22:59, 14 March 2018 (UTC)
The occurrence of trachyandesite and trachyte has also been described, and I see the source cites it to "De La Cruz, N. & De La Cruz, O.: Memoria explicativa de la revisión geológica del cuadrángulo de Tarata (35-v), informe inédito. Lima. Instituto Geológico Minero y Metalúrgico, (2001), 19 p." Would it be worth trying to get hold of this, e.g. via WP:RX? Pauccara and Matsuda say "The Tutupaca volcano consists of an alternating sequence of pumice pyroclastic flows and ash with massive blocks. It is followed by an important sequence of andesitic and trachytic lavas flows, and finally a trachyandesitics debris flow tuff with abundant hornblende crystals containing, biotite, pyroxene and quartz." Do you think the original source would have more details?
The volcanic rocks erupted during the Holocene define a potassium-rich calc-alkaline suite. Dacites from eastern Tutupaca contain amphibole, apatite, biotite, clinopyroxene, iron-titanium oxides, orthopyroxene, plagioclase, quartz and sphene.You say above that Samaniego 2015 is only talking about Holocene eruption products, so how about joining these two sentences so it's clear that applies to the second one? I know we said earlier that only eastern Tutupaca is Holocene, but we could remind the reader at this point: "The Holocene-era eruption products of eastern Tutupaca define a potassium-rich calc-alkaline suite, and its dacites contain amphibole, apatite, biotite, clinopyroxene, iron-titanium oxides, orthopyroxene, plagioclase, quartz and sphene."
More tonight. Mike Christie ( talk - contribs - library) 11:07, 14 March 2018 (UTC)
Based on 30 whole-rock major and trace element analyses, the Holocene eruptive products of Tutupaca volcano are classified as high-K calc-alkaline dacites (Fig.9). All samples from the Eastern Tutupaca domes display a very restricted dacitic compositionand so on with the exxact minerals later. I am not sure if there is any significance to the fact that Samaniego 2015 differentiates here between "Holocene eruptive products of Tutupaca volcano" and "Eastern Tutupaca domes".
-- Mike Christie ( talk - contribs - library) 23:27, 16 March 2018 (UTC)
Off the coast of Peru, the Nazca Plate subducts at 5–6 centimetres per year (2.0–2.4 in/year) beneath the South America Plate.[24][10] This subduction process is responsible for the volcanism in the Central Volcanic Zone[c] of the Andes, which includes the volcanoes of Peru's Western Cordillera.[24] (The Central Volcanic Zone is one of four volcanic belts in the Andes, together with the Northern Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone.[25]) Aside from Tutupaca, Peru also features the volcanoes Sara Sara, Solimana, Coropuna, Andagua volcanic field, Ampato-Sabancaya, Chachani, El Misti, Ubinas, Huaynaputina, Ticsani, Yucamane and Casiri.[10] Major historical eruptions happened at El Misti 2,000 years ago and at Huaynaputina in 1600.[24]I'd like to change this to: "Off the coast of Peru, the Nazca Plate subducts at 5–6 centimetres per year (2.0–2.4 in/year) beneath the South America Plate, causing volcanism in three of the four volcanic belts in the Andes, including the Central Volcanic Zone, where Tutupaca is located. Other Peruvian volcanos include Sara Sara, Solimana, Coropuna, Andagua volcanic field, Ampato-Sabancaya, Chachani, Ubinas, Ticsani, Yucamane, and Casiri. Major eruptions have occurred at El Misti, 2,000 years ago, and at Huaynaputina, in 1600." (After the mention of the CVZ, put a note with what's currently in parentheses.) This is enough of a rework that I wanted to check it with you. Also, we list Peruvian volcanoes, but the CVZ includes Chilean volcanoes too, doesn't it? Any reason to include these specifically? Does the list of other volcanoes add to the reader's understanding? Mike Christie ( talk - contribs - library) 15:19, 17 March 2018 (UTC)
Tutupaca is about 700,000 years old.[29] The older complex was active at first with lava flows and then with a major explosive eruption,[3] all of which took place over 25,000 years before present.: It seems a little odd to say that the volcano is about 700 ky old, and then say it's "first" activity was over 25,000 years ago. I see Scandiffio et al says "The age of Tutupaca volcano is estimated around 0.7 M.a", but I can't see Samaniego et al.; what does it say exactly?
their occurrence is supported by radiocarbon dating of eruption products: Do Samaniego and Valderrama directly contradict each other re whether these are Tutupaca or Yucamane eruptions? If not I think we can combine these sentences and shorten things.
218 ± 14 years before present[20], probably in 1802: this is inconsistent, isn't it? 1950 - 218 = 1732. If "present" means "date of the paper" I would make it either "152 ± 14 years before present" with the link to BP, or "1798 ± 14 years", to avoid tying the estimate to the date of the paper.
-- Mike Christie ( talk - contribs - library) 22:33, 17 March 2018 (UTC)
. These moraines are probably formed during the Last Glacial Maximum (LGM), which has been broadly dated at 17–25 ka in the Western Cordillera of the Peruvian Andes (Smith et al. 2008; Bromley et al. 2009)... This ignimbrite deposit is covered by the LGM moraines, suggesting an age older than 25 ka.
esults of this calibration procedure show that the five samples are statistically identical at a 95 % confidence level with a pooled mean of 218±14 aBP. The calibrated calendar age for this average 14C age yields two age spans, the most important being 1731–1802 cal AD period (with a relative area of 85 %). We emphasise that the two historic eruptions (1787–89 and 1802 AD) reported by Zamácola y Jaúregui (1804) and Valdivia (1847) fall at the end of this period.. This is just odd. BTW, the reason why the collapse is linked to the 1802 eruption is because historical reports indicate that the 1802 eruption was stronger than the 1787-1789 one.
Given the conversation above, here's a possible rewrite for the 1802 section and the paragraph just above it.
The [note] would say something like "The uncalibrated radiocarbon age of the samples is 218±14 years before present, with 95% confidence; the calibrated age consists of two ranges, with an 85% probability that the date lies between 1731 and 1802."
I changed "radiocarbon dating of eruption productions" to just "radiocarbon dating" since it seems impossible that the actual eruption products could have been dated. I included your note about why the 1802 eruption is thought to be associated with the collapse; I don't know which source that comes from. How does it look? Mike Christie ( talk - contribs - library) 13:40, 18 March 2018 (UTC)
There are reports of eruptions in 1780, 1787, 1802, 1862 and 1902 which are supported by radiocarbon dating of eruption products.sounds like we are saying that radiocarbon dating supports the existence of each eruption, which is not correct. Sourcing the "now believed to be at Tutupaca" is dicey, I'd probably use the GVP citation, the impression I have is that this is the now accepted consensus not just Samaniego's opinion.
and is thought to be associated with the 1802 eruption since historical reports indicate it was stronger than the 1787-1789 eruption., that is logical inference but Samaniego 2015 does not explicitly give this thought process. Other than these points I like the rewrite. Jo-Jo Eumerus ( talk, contributions) 14:26, 18 March 2018 (UTC)
Here's another draft that tries to take those points into account:
-- Mike Christie ( talk - contribs - library) 23:54, 19 March 2018 (UTC)
Some authors believed that Yucamane volcano was a more likely source for these eruptions, but Samaniego et al. (2015) showed that Yucumane last erupted 3,000 years ago, and the other eruptions, in particular those of 1787-1789 and 1802, most likely occurred at Tutupaca.with "and the other eruptions, in particular those of 1787-1789 and 1802, most likely occurred at Tutupaca." sourced to the GVP article on Tutupaca. Jo-Jo Eumerus ( talk, contributions) 09:40, 20 March 2018 (UTC)
I copyedited the lead; does that look OK? Can you add any more details from the body? I think this is about ready to nominate. I'd like to read it through one more time, probably tomorrow, to see if I can spot anything else, but it's more or less there. Mike Christie ( talk - contribs - library) 02:36, 21 March 2018 (UTC)
Two more points.
Other than that I think this is ready to go once you hear from Ceranthor. Mike Christie ( talk - contribs - library) 10:02, 21 March 2018 (UTC)
Sorry for my delay, real life's been a bitch lately! ceran thor 02:38, 27 March 2018 (UTC)