Talk:La Reforma (caldera)

GA Review

This review is transcluded from Talk:La Reforma (caldera)/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Tisquesusa (talk · contribs) 06:16, 26 January 2017 (UTC)

Review

Under review, Tisquesusa (talk) 06:16, 26 January 2017 (UTC)

GA review – see WP:WIAGA for criteria

1. Is it well written?

   A. The prose is clear and concise, and the spelling and grammar are correct:

   The text is in parts written not really clearly (confusing, contradictory) or awkwardly (using repetitive words, non-geological, tautologies), some wordings are not really geological, detailed review of this:

Intro

• "A volcanic arc had existed on the peninsula." - needs clearer wording; what was the volcanic arc, how did it affect this caldera and what was the age range of existence
• "The caldera has a diametre of 10 kilometres (6.2 mi); its formation was accompanied by the eruption of a 5–10 cubic kilometres (1.2–2.4 cu mi) ignimbrite." - the sentence about the size should be separate from the rest and contain the maximum elevation of the rim and the depth of the caldera. "formation accompanied"? What about "the formation of the caldera was the result of a series of eruptions that produced an ignimbrite of 5-10 km3"?
• "After the eruption, volcanic activity continued in and around the caldera and its centre rose about 300 metres (980 ft)." - the caldera was formed by 1 eruption? What was the volcanic activity inside the caldera and what did it produce? Idem for the around the caldera part. What was the cause of the 300 m rise (uplift would be a better word?)?

Geography and structure

• "El Aguajito, west of La Reforma; the latter was first identified in 1984 as the "Santa Ana caldera"." - I would rephrase this, now "the latter" seems to refer to La Reforma, not El Aguajito
• The next paragraph is not so much about the geography, more about the origin of La Reforma, and the tectonics/geology, should be placed under geology. Geography should be expanded and include more information on the geographical characteristics; how does the volcanic area continue subsea to the east too.
• "Baja California is currently moving northwest at a rate of 5.6 centimetres per year (2.2 in/year). As part of this event, the Santa Rosalia basin formed and was filled by a number of Miocene-Pleistocene formations, some of which are exposed in La Reforma." - "As part of this event", which event? The transform fault activity? And is it an "event"; a single occurrence, or a wider tectonic framework? "the basin was filled by formations" - the basin is filled by sediments or volcanic lithologies that produce formations. A formation isn't something on its own, it is the grouping of lithologies of certain character; the result of geological analysis.
• "A central block rises 700 metres (2,300 ft) above the rim of the caldera" - a central block seems to indicate centered, but where? Inside the caldera? And if it rises 700 m above the rim of the caldera, and that rim is already 100-500 m high, it's a pretty high beast, maybe a bit more expansion on this to show the geography and structure of the area.
• "Alternative theories suggest that La Reforma is a dome which eroded in a circular pattern or a set of tectonic blocks." - I wouldn't say "alternative theories suggest", rather "alternative theories are...", or "Other geologists suggest...", the "or a set of tectonic blocks" refers to "eroded in" or the characteristic of the caldera itself? Some more expansion from the reference that provides this "alternative theory" would be nice, also to give it more weight; apparently the research is not conclusive (yet).
• "Although the dome was thought to be formed by the Comondú volcanics, it appears to be a product of La Reforma activity." - "the Comondú volcanics" are not explained here yet, that comes in the next chapter.

Geology:

• "Subduction was prevalent in the region until 12,500,000–11,000,000 years ago; volcanic activity since then is due to tectonic changes associated with the development of the Gulf of California. Earlier subduction-related volcanism formed the so-called Comondú volcanics." - subduction of which plate underneath which plate? I wouldn't write out the millions of years in a range like this, maybe better 12.5-11 Ma/Mya. The Gulf of California is a geographical representation of a geological cause (together with sealevel changes); the Santa Rosalia basin, more expansion of that would limit confusion. "Earlier subduction-related volcanism" - when was that? Part of the subduction sequence of the Miocene, or before that?
• "The last subduction-related volcanism, producing Santa Rosalia dacite, was between 13 and 12 million years ago." - this contradicts the first sentence of this chapter, where it says "prevalent until 11 Ma", between 12 and 11 Ma there was no volcanics produced by subduction?
• "The subsequent rifting-related volcanism laid down" - rifting? How was this rift produced? Rifting is extensional tectonic movement, but earlier I learned it was subduction and then transform (strike slip) movement? Back-arc extension could happen, but that isn't rifting.
• Like I mention in 3a, it would be nice to have a table summarising these events and products.
• The last paragraph about the volcanoes should be the leading one of the geology chapter and there the Comondú volcanics, that isn't quite clear yet to me, should be included and explained in more detail.

Rocks

• "Based on outcrops, the basement dates to the Cretaceous and was formed by granitic rocks." - not "based on outcrops", but "based on outcrop analysis", the Cretaceous is very long, when was the basement formed? The basement is not "formed by" granitic rocks, but "composed of" them. Are there any changes in the crystalline basement; different types of granite? What was the cause of these intrusives? And how is the relation with the tectonic framework; how are the intrusives uplifted and when, to get an extrusive young volcanic sequence on top of an intrusive basement?
• "Other parts of the basement are Miocene marine sediments and the Comondú volcanics." - the sentence before says that the basement is granitic. Better to expand like "the deeper parts of the basement are composed of (Early, Late, "Campanian" or so) Cretaceous granites, while the top part comprises (deep, shallow, marginal?) marine sediments of Miocene age" - also the position of the Comondú volcanics, where is it? A table showing the geological sequence would solve this confusion. The Comondú volcanics are now named 3 times but what they are and what composition they have and how they are related to the tectonic regime still are unclear to me.

Composition:

• "Lava flows are made of andesite, basalt and dacite, and lava domes are made out of rhyolite." - twice "made" in one sentence doesn't look nice. But the wording is not ideal anyway. What about "Lava flow deposits are composed of a, b, d and lava domes are consist of rhyolite"?
• "Pliocene rocks contain clinopyroxene and feldspar." - clinopyroxene and feldspar are among the most common minerals of volcanic rocks, so not very special. I assume the Miocene rocks also contain these minerals. If there's a more detailed mineral composition available from the sources, that are unfortunately inaccessible to me or any other reader without journal access, should be summarised in a table, like you did with your other articles (e.g. Lake Tauca) very nicely.
• Plagioclase, apatite, magnetite and zirconia are also present. The ignimbrites also contain feldspar and clinopyroxene. Some of the last erupted rocks also contain amphibole. The area contains deposits of Cu and Mn. Some rocks have been converted into palagonite." - three times "also" doesn't read very well. - Plagioclase is not special for volcanic rocks. "The ignimbrites also contain Fs and Cpx", again very common and the same as what you say about "Pliocene rocks". Again, a table summarising the differences and similarities between the different ages, compositions and rock types (dacites, andesites, basalts, ignimbrites, etc.) solves this confusion. "Some of the last erupted rocks contain amphibole"? - Eh, yes, if they are volcanic and mafic/basaltic, that's normal, right? "The area contains deposits of Cu and Mn", now that is quite special! Should be elaborated. And "deposits of Cu and Mn" indicates sedimentary deposits? Or where are they coming from? Or Cu and Mn part of Cu- and Mn-bearing minerals? Which ones? "Some (which?) rocks have been converted into palagonite", as a geologist, I didn't know what palagonite was, but it seems related to volcanic glass. There is no mentioning of glasses anywhere here, it's all crystalline. Needs some expansion or rather leave it out. Other forms of palagonite are explained in that article, but then the relation with La Reforma is not clear; in which rocks; of which rock type/mineralogy and which age and which location (inside the caldera, ignimbrites, crater rim or so) are those palagonites found?
• "The elemental composition of La Reforma volcanic rocks resembles calc-alkaline volcanism." - resemble is the wrong word here. Composition A can resemble composition B, but here it reads that a composition resembles a cause. "The elemental composition of La Reforma resembles products of calc-alkaline volcanism" or "The volcanism of La Reforma resembles calc-alkaline volcanism".
• "This is consistent with the geochemistry of nearby Tres Virgenes, although one pyroclastic flow at La Reforma was considered peralkaline." - again, a table listing the differences between the different volcanoes of the area would solve confusion. I read in the abstract of the ref that Aguajito has a minimum of 10 km3 products and those are only the acidic ones. The intro of La Reforma says 5-10 km3 (in total), so La Reforma is much smaller than Aguajito. A table could list the differences in volumes of the 11 volcanoes of this field.

Climate:

• far too short and too little information, see 3a

Eruptive history

• "Volcanism at La Reforma began during the Pliocene, with ash flows and subaqueous pumice flows. Later activity became subaerial and generated pillow lava." - there is no more specific age dating available for "during the Pliocene"? And before I learned that the general geology of the area is subduction-related volcanism of the Miocene. What is the cause for the difference of La Reforma (young) and the other volcanoes (older)? "Later activity", when? Still Pliocene? Pleistocene? What was the cause for first subaqueous and then subaerial? A different volcanic vent shifting eruption from subsea to terrestrial? Regional uplift of the same vent?
• "Of the local volcanoes, La Reforma was the first to emerge from the sea. Four to five million years ago, basaltic dykes formed. Volcanic activity at La Reforma occurred between 1.6 and 1.4 million years ago, and at least four ignimbrites have been found there." - so now it's explained when the Pliocene volcanism occurred, but "1.6-1.4 Ma" is Pleistocene? Basaltic dykes are named as Pliocene (4-5 Ma). But what does 4-5 Ma mean? Between those ages? Then the older should be before the younger. Or is it unclear which age the dykes were formed, so "somewhere between 4 and 5 Ma"? Needs expansion to solve this confusion.
• "A major ignimbrite-forming eruption occurred during the early Pleistocene, with the formation of pantellerite tuff. The eruption covered about 200 square kilometres (77 sq mi) with 5–10 cubic kilometres (1.2–2.4 cu mi) of ignimbrite. The ignimbrite is rich in fiamme. Andesitic effusive activity occurred on the flanks of the caldera before and after its collapse." - the major eruption was the first (listed above as 1.6 Ma)? or a later one (1.4 Ma is still Early -should be capitalised- Pleistocene). 5-10 km3 is a spread of 100%, is there more data available in the refs to funnel this down? Or is it really so uncertain? "before and after its collapse"? I read about the collapse for the first time, should be explained when this collapse occurred before in the text to solve confusion.
• "Some La Reforma eruption products were later buried by activity from El Aguajito, where volcanic activity migrated" - "migrated to", but anyway it doesn't read nicely. What about "During the Late Pleistocene (age range?), the volcanic activity shifted from La Reforma towards El Aguajito (in the west, north, south, east?). Eruption products of El Aguajito buried earlier formed La Reforma rocks"? - I would remove "some" as well, as it is vague. Or specify which ones or where, or just leave it out.
• "Basaltic cones which erupted 600,000 years ago on the caldera's flanks are tectonically unrelated; like Isla Tortuga and Tres Virgenes, they are controlled by the extension of the Sea of Cortez." - this makes no sense. If the eruption of the cones are "tectonically unrelated", they cannot be "controlled by the extension", because extension is a tectonic process. Also, the Sea of Cortez doesn't extend, the basin below it can be extensional. The sea is just a geographical representation of basin+sea level. And again it's unclear to me what kind of extension? I read "rifting" and now "extension", but the only tectonic movement explained before is transform faulting. If it's oblique (strike-slip + extension), it needs to be explained in the geology section, with possibly a separate chapter called "Regional tectonics".
• "Fluvial deposits were laid down in the caldera." - from where? First time I read about fluvial, no mentioning of rivers anywhere before. Also "deposits laid down" doesn't read well; tautology-like. "Deposits formed" or "sediments laid down", but "laid down" I would avoid in any case.
• "Seismic activity occurs in the area, and future large-scale explosive activity is possible." - this is far too little information cramped in 1 sentence. Seismic activity occurs in the area; where? How strong? Any historical earthquakes? What depths of the hypocentre? Along which faults? "future large-scale explosive activity is possible" - means this caldera is part of an active or dormant volcano, yet the last eruptions mentioned before are the basaltic cones at 600 ka (not large-scale and apparently not "tectonic-related"), the last major ignimbrite was Early Pleistocene and the last "volcanic activity" occurred between 1.6 and 1.4 Ma (just now I see it's contradictory too; the last dated volcanic activity is represented by the basaltic cones at 0.6 Ma, much later than what is said before?)
• "The centre of the caldera was affected by resurgent doming, triggering the exposure of Miocene-age rocks (including diorites)." - I would say "The centre of the caldera experienced resurgent doming (when?), resulting in the exposure of Miocene-age intrusive (diorite is intrusive) rocks"; the trigger is tectonics, the result is doming and thus exposure - what is "resurgent doming" and how is it related to the overall tectonic regime of the area? Also first time I read diorites. We had Cretaceous granites, and now Miocene diorites, but also the Miocene ("12.5-11 Ma") is extrusive in the area?
• "Uplift of the surrounding land raised Pleistocene sea deposits to over 300 metres (980 ft). The average pace of the uplift is 240 millimetres per kiloare (8.8×10−6 in/sq ft)." - uplift of the surrounding land? Not the caldera itself, that keeps static at 300 m lower? Cannot imagine. "Uplift of the regional area" I'd say then. There is a "clarification needed" tag there but on the Talk page it's not mentioned, indeed it's unclear what you mean. "Pace of uplift" is height/time unit, now it's shown as height/area. "Regional uplift raised Pleistocene marine deposits to altitudes exceeding 300 m above sea level" would be a better phrasing I guess.
• "The existence of a magma chamber beneath La Reforma is suggested by springs in the area, which contain small amounts of magmatic water." - I would avoid "suggested" again here. And what is "magmatic water"? "Hydrothermal activity, resulting in hot springs in the area, point to (or synonym) a possible magma chamber present underneath La Reforma and surrounding volcanoes" or something along those lines.
• "Temperatures of the hot springs range from 21 to 98 °C (70 to 208 °F), and the area has been investigated as a potential source of geothermal energy." - the geothermal energy part is quite special, not every volcano in the world is studied as a potential source for geothermal energy. Needs expansion and possibly a separate chapter if there's enough information about it.

1. B. It complies with the manual of style guidelines for lead sections, layout, words to watch, fiction, and list incorporation:

   Lists should be included about: 1) the sequence of formations, to clarify what the text says, 2) the flora and fauna of the region, see for more point 3a

2. Is it verifiable with no original research?

   A. It contains a list of all references (sources of information), presented in accordance with the layout style guideline:

   I would put the articles you use in the "Bibliography" (not "Sources") section and have the refs section refer to that, using the harv templates you used already. Also "et al." for more than 2 authors ("Garduño-Monroy, Vargas-Ledezma & Campos-Enriquez" -> "Garduño Monroy et al.").

   B. All in-line citations are from reliable sources, including those for direct quotations, statistics, published opinion, counter-intuitive or controversial statements that are challenged or likely to be challenged, and contentious material relating to living persons—science-based articles should follow the scientific citation guidelines:

   The ref to "Demant, 1984" is the only accessible one for me without journal access. But the link, this one refers to a book with different authors. I imagine the paper by Demant is included in this book, but then it needs to be showing in the refs with chapters like "work=A, by editors Malpica Cruz et al. ; chapter=B, by author Demant".

   C. It contains no original research:

   No problems

   D. It contains no copyright violations nor plagiarism:

   No copyvio

3. Is it broad in its coverage?

   A. It addresses the main aspects of the topic:

   Not complete yet:

• Infobox needs to be added
• Coordinates should be in DMS (Degree-Minute-Second) form, using a DMS converter
• The introduction is too short for the article and when the "could produce another large-scale eruption" part is expanded that definitely should be mentioned in the intro; it's showing that this caldera is potentially dangerous
• The various chapters need expansion too; the climate should contain temperature information and ideally a climate chart of a nearby location, prevalent wind directions would be nice to have included
• Something about the hydrology, are there any rivers, lakes, "wadis" (dry river beds in the arid region), erosion, etc.
• Also missing is the flora and fauna of the area; being arid, the flora would be sparse, but then which flora is present and which animals populate the caldera or nearby regions
• Chapter about human population/nearby settlements (one is shortly mentioned)/tourism/first ascent should be added
• See also section to refer the reader to other volcanoes or calderas of this type, ideally with quality ranking using icons (to discriminate good/B/C-class from start-class articles)

1. B. It stays focused on the topic without going into unnecessary detail (see summary style):

   Not too detailed

2. Is it neutral?

   It represents viewpoints fairly and without editorial bias, giving due weight to each:

   No problems

3. Is it stable?

   It does not change significantly from day to day because of an ongoing edit war or content dispute:

   No problems

4. Is it illustrated, if possible, by images?

   A. Images are tagged with their copyright status, and valid fair use rationales are provided for non-free content:

   No problems

   B. Images are relevant to the topic, and have suitable captions:

   More images are needed, especially maps, showing the position of the caldera within the SW US-NW Mexico area, its relation with the tectonics of California/Baja California and the topography. Also relevant images of the arid landscape and if available (either on Commons or to be imported from Flickr or panoramio) photos from outcropping rocks of the caldera or the volcanic products surrounding it. Link to Commons in the external link section at the bottom would be nice.

5. Overall:

   Pass or Fail:

   Article is not there yet. It needs expansion of and solving the many confusions and some contradictions within the various chapters and some other ones added, see above under 3a and 1a. The tectonic framework and evolution is still unclear, overall the sequence would be Miocene subduction and then Plio-Pleistocene transform movements, but also extension and even rifting is mentioned. Images, maps, infobox and explanatory lists (e.g. the sequence of formations and the nearby volcanoes in a list with coords and elevations would be nice) need to be added. References should be clear in terms of which author appears in which book in which chapters and pages, one accessible example is mentioned above. In general the article cramps too much information into too short sentences which makes it unclear for even a geologist to understand the geology of this caldera. After reviewing several of the volcano articles by this author, La Reforma is objectively not of the same quality of his other GAs. Tisquesusa (talk) 17:39, 27 January 2017 (UTC)

Oy wey. @Tisquesusa: I'll admit that I found this article far more borderline than many of the other volcanoes I've nominated and that I am not certain if it will pass at the end; I've worked on the lead section and the Geography one though, will continue tomorrow. Jo-Jo Eumerus (talk, contributions) 20:02, 27 January 2017 (UTC)

@Tisquesusa: Took care of a few more issues in the geology section as well as the harv error. Seems to me like the last subduction related volcanism and the end of subduction do not necessarily to have to coincide, so left that one unmodified. Jo-Jo Eumerus (talk, contributions) 19:52, 28 January 2017 (UTC)

@Tisquesusa: About the "basement" bits, I think that basement here can be used to generally refer to rock layers that are not part of the volcano. I've expanded the section in question; also, is comondu volcanics explained earlier well enough now? Jo-Jo Eumerus (talk, contributions) 20:10, 29 January 2017 (UTC)

Basement

Yes, very right Jo-Jo, I saw it. Today's my birthday so having some time off from the article. I call it crystalline basement, as a common geological term, the Miocene marine seds would be still basement but not crystalline (granites and monzonites). Cheers, Tisquesusa (talk) 21:08, 29 January 2017 (UTC)

@Tisquesusa: Update; I'll see to have all outstanding issues resolved tomorrow. Jo-Jo Eumerus (talk, contributions) 21:28, 1 February 2017 (UTC)

Ok, remedied a number of issues. I think that there is not enough information for many more tables, especially not dating information. Since you asked about the 0.6 million year old volcanoes, they don't seem to be related to La Reforma other than being in the same place. I also wonder if the Demant-Ortlieb source should be discarded; it reads more like an abstract and is overly vague in a number of points. Jo-Jo Eumerus (talk, contributions) 11:44, 2 February 2017 (UTC)

Tisquesusa, Jo-Jo Eumerus, where does this review stand now? I see that major edits were made on February 2, including a couple by Tisquesusa after Jo-Jo Eumerus finished, but there hasn't been any follow-up here. Thanks. BlueMoonset (talk) 17:17, 12 March 2017 (UTC)

@BlueMoonset: Waiting for replies by Tisquesusa. Jo-Jo Eumerus (talk, contributions) 17:22, 12 March 2017 (UTC)

Some improvements have been made but most of the issues are not solved, especially the lack of coherence between dates. In geological literature that may happen due to different dating methods, areas, etc. But it's the task of a writer to summarise and streamline those differences, not just simply replicating every age and create confusion where that isn't there in the first place. Infobox is marginal, article is just not ready yet. I have made a very detailed list of points of which some were addressed, but the most important ones still stand. Tisquesusa (talk) 18:45, 12 March 2017 (UTC)

@Tisquesusa: Honestly, I don't think I'll be able to address these issues given the problem of insufficient sources and that I've been working on other articles in the meantime. This nomination should probably be failed. Jo-Jo Eumerus (talk, contributions) 19:11, 12 March 2017 (UTC)