Wikipedia talk:WikiProject Geology/Archive 8

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Archive 7

Archive 8

Portals Nominated for Deletion

The portals Portal:Mesozoic, Portal:Paleozoic, and Portal:Cretaceous have been nominated for deletion. Just to restate the non-obvious, the articles have not been nominated for deletion. The deletion discussions are at:

• Wikipedia:Miscellany for deletion/Portal:Mesozoic
• Wikipedia:Miscellany for deletion/Portal:Cretaceous
• Wikipedia:Miscellany for deletion/Portal:Paleozoic

Your involvement is invited. Robert McClenon (talk) 19:30, 22 January 2024 (UTC)

A shame, honestly! I quite liked portals, they've just never really been part of an intuitive way to use the site. The only portal you're likely to encounter in regular use is the main page. --Licks-rocks (talk) 22:02, 22 January 2024 (UTC)

One of the problems with portals is that they are fun to create, but maintaining them is tedious maintenance work. The main page has a lot of volunteers who work to maintain it, and they evidently enjoy what they are doing, but it gets a lot more visibility than maintaining a portal on an era. Robert McClenon (talk) 16:37, 26 January 2024 (UTC)

Impact structures

A significant number of the impact structures identified on Earth are described on Wikipedia as "impact craters" even when this is not how the majority of sources describe them. Rochechouart, Vredefort and Popigai have all been moved, but there are many others that should also be moved, based on an analysis of Google Scholar results: Acraman, Tookoonooka, Araguainha, Saint Martin, Woodleigh, Carswell, Manson, Shoemaker, Mistastin, Steen River, Tunnunik, Gosses Bluff and Dhala. Additionally the list of impact craters on Earth should be moved to list of impact structures on Earth. Thoughts? Mikenorton (talk) 21:43, 24 January 2024 (UTC)

I think that describing impact structures erroneously as craters is widespread in a lot of lay literature, and to a lesser extent some academic papers. I'll get around to making move requests for all of these in the next week. Hemiauchenia (talk) 00:23, 25 January 2024 (UTC)

Thanks, I've started the ball rolling with a move request for the list. Mikenorton (talk) 11:40, 25 January 2024 (UTC)

Aye, even in academia the terms are used loosely. Jo-Jo Eumerus (talk) 07:50, 25 January 2024 (UTC)

I'm aware that "crater" is used rather loosely. Having visited the Siljan Ring, I'm more than surprised to find it called a crater in some scientific journal articles , although in some cases they're talking about the original form of the crater at the time of impact. Mikenorton (talk) 11:40, 25 January 2024 (UTC)

I've just noticed that the categories would also need sorting out. Vredefort (and other similar highly eroded structures) are in subcategories that sit within the category "Impact craters on Earth". Mikenorton (talk) 17:29, 25 January 2024 (UTC)

I agree. The categories also need to be sorted out. Paul H. (talk) 01:52, 1 February 2024 (UTC)

Update - I've moved most of those listed above, but left three of them as further analysis showed that the naming was more equivocal than I had first thought. I've also moved all the lists by continent. That leaves the lists by country and the categories. I've contacted user:Ikluft regarding the categories as this would be a major change to a category tree that they set up. None of the moves have been contested (yet). Mikenorton (talk) 20:05, 20 February 2024 (UTC)

What are the three "impact craters" that "...further analysis showed that the naming was more equivocal than I had first thought."? Paul H. (talk) 21:38, 20 February 2024 (UTC)

Araguainha, Mistastin and Tunnunik. Mikenorton (talk) 21:58, 20 February 2024 (UTC)

Flammenmergel

Hi, just wondering if someone could look at Flammenmergel - it doesn't seem to contain much information and could maybe be merged somewhere else (but I'm not sure where). Thanks. JMWt (talk) 15:39, 23 February 2024 (UTC)

There is an entry for the Flammenmergel formation in the BGR online Litholex lithostratigraphic lexicon for Germany. Mikenorton (talk) 16:49, 23 February 2024 (UTC)

Looking at that, I see that the Group that this formation forms part of does not have an article, so that reduces our options. The list of sedimentary formations in Germany might be an option if all the wikidata from here was added in (although the Flammenmergel is not included I note). Mikenorton (talk) 17:27, 23 February 2024 (UTC)

Eemian or Last Interglacial?

I assume paleoclimatology is in scope for this project? I've been doing some reading about the topic of the Eemian/Last Interglacial, and it seems to me that Eemian is really a Europe specific term, and that "Last Interglacial" is more widely used in the scientific literature for global coverage of this period, often without mentioning the term "Eemian" at all. Should the title of the article be changed? Hemiauchenia (talk) 21:10, 24 February 2024 (UTC)

Could be. The last interglacial is known under several names of which "Eemian" is the most common but still less common than "Last Interglacial". Jo-Jo Eumerus (talk) 08:03, 25 February 2024 (UTC)

I've made a move request, see Talk:Eemian#Requested_move_28_February_2024. Hemiauchenia (talk) 00:31, 28 February 2024 (UTC)

Requested move at Talk:Eemian#Requested move 28 February 2024

There is a requested move discussion at Talk:Eemian#Requested move 28 February 2024 that may be of interest to members of this WikiProject. Vanderwaalforces (talk) 09:13, 28 February 2024 (UTC)

Proposal to remove the rankings for low abundance elements in the table

Please weigh in on my proposal on Talk:Abundance of elements in Earth's crust to split the table on that page. Johnjbarton (talk) 16:01, 21 March 2024 (UTC)

Stratigraphy model article

Among other topics I'm hoping to work on for the project, I have a hobby interest in geology, and thought I could do some good attending to the infinite list of tiny, poorly-written stratigraphy articles. Obviously, not all units are created equal but as I'm bungling around with these, a format exemplar would sure be handy. Is Marcellus Formation the best model article to use as far as overall structure and article goals are concerned? Lubal (talk) 19:59, 12 March 2024 (UTC)

Hi Lubal. The Marcellus Formation does indeed look a good model to follow. Not sure you'll find that level of detail on many other formations though! If you're interest in UK units the BGS Lexicon of Named Rock Units is a good place to start. Silica Cat (talk) 11:36, 14 March 2024 (UTC)

The Marcellus and Touchet formation articles are the most detailed ones I'm aware of. I also redid the Big Raven Formation article recently which is a GA nominee. Volcanoguy 14:04, 14 March 2024 (UTC)

Appreciated! Having some idea what the structure should look like makes this a lot easier. I'm going to be starting with Kansas/Missouri stratigraphy which seems fine, because wow, that subtopic area needs some love. I've been cleaning up Bonneterre Formation, but I'll probably move things around there a little bit before adding more content (of which there's quite a bit, including economic impact), just so it's laid out vaguely like the existing high-quality articles. Not that I'm going to pretend I'm writing high-quality articles, at least not yet. Lubal (talk) 14:14, 14 March 2024 (UTC)

I should note that since all geological formations are of different sizes and compositions it would be impossible to bring all articles about formations up to the level of detail as the Marcellus Formation article, especially if there's less information about a specific formation. Both Big Raven Formation and Edziza Formation passed GAN this month. Volcanoguy 22:10, 7 April 2024 (UTC)

Proposal to merge the sub-articles on crystalline types of ice

Please weigh in on my proposal on Talk:Ice#Merge all the ice sub-types into Phases of ice? to merge content from that page and the linked stub/start-class pages into a single medium-sized page. InformationToKnowledge (talk) 16:49, 10 April 2024 (UTC)

Members and supergroups

While I was looking through the stratigraphic unit article I noticed member (geology) and supergroup (geology) don't have articles while the other three types of units (bed (geology), geological formation and group (stratigraphy)) have articles. Does anyone have an explanation for why this is? Volcanoguy 20:53, 15 March 2024 (UTC)

@Volcanoguy: my best guess is that all stratigraphy is subdivided into formations and many of those are "grouped" into groups but that supergroups are relatively unusual (see category:Geological supergroups) and very few members are notable (see category:Geological members. As to "bed", there is a lot to say on the topic. Mikenorton (talk) 16:41, 10 April 2024 (UTC)

@Mikenorton: Is there proof or evidence that very few members are notable? I understand most members redirect to formation articles but that could be because the member is not notable, few users have had the courage to write member articles or because there's no need for a separate member article; most formation articles I've seen aren't that big so splitting them would be unnecessary. Volcanoguy 17:08, 10 April 2024 (UTC)

@Volcanoguy: Agreed, that is mostly why we don't have articles on individual members - formation articles are often only stubs anyway. A lot of our formation articles were created related to their fossil content and there has always been the presumption of notability for any formation article. I'm not sure that I can prove my suggestion about members, just a (probably unreliable) feeling. I've only worked on the Stac Fada Member, where notability was not a concern. Mikenorton (talk) 19:17, 10 April 2024 (UTC)

@Mikenorton: The only member article I've created so far is Sheep Track Member out of WP:UNDUE concerns; the Sheep Track Member section in the Big Raven Formation article being more detailed than the other sections could have been problematic because the Sheep Track Member is only a minor sub-unit of the Big Raven Formation. Volcanoguy 16:06, 11 April 2024 (UTC)

Unbalanced hypothesis presentation at Table Mountain (Tuolumne County, California)

I see that the "Sierra did not uplift strongly in the Pliocene" hypothesis is presented as a dominant theory at Table Mountain (Tuolumne County, California). IIUC, this is a minority hypothesis: it isn't exactly fringe, but it isn't commonly accepted (again, as far as I know).

I could dig into this, but I don't have the time to do it justice. Would any other editor like to step in? — hike395 (talk) 04:55, 10 April 2024 (UTC)

If I somehow find the time I will take a look at it. Could be today, could also be in half a year, but it's on the list. --Licks-rocks (talk) 09:02, 10 April 2024 (UTC)

Thanks! — hike395 (talk) 16:05, 10 April 2024 (UTC)

I have a large of PDFs of papers, disertations, theses, etc. about the geology of the Table Mountain in Tuolumne County, California, the Sierra Nevada, the "auriferous gravels," Ione Formation, and so forth. I have been meaning to use these to work on this and other articles. I guess it is time to look through all of this and see what I can do to revise this article. Paul H. (talk) 14:32, 12 April 2024 (UTC)

I think there are two different hypotheses that being discussed at this time:

1. One is that "...the Sierra Nevada has existed as a major topographic feature since at least the Late Miocene with mean elevations comparable with the modern..." \and

2. "...large-magnitude surface uplift in the last 3–4 Ma as a result of delamination and removal of a dense continental lithospheric root beneath the Sierra Nevada (46–49).

For an example, go see:

Mulch, A., Sarna-Wojcicki, A.M., Perkins, M.E. and Chamberlain, C.P., 2008. A Miocene to Pleistocene climate and elevation record of the Sierra Nevada (California). Proceedings of the National Academy of Sciences, 105(19), pp.6819-6824. Paul H. (talk) 15:42, 12 April 2024 (UTC)

Yes, you are correct. When I was talking about the minority hypothesis, I was referring to your hypothesis #1. I also have seen papers on hypothesis #2. I don't know the level of acceptance of hypothesis #2. To make things more complex, if I understand correctly, the delamination hypothesis appears to explain uplift in the south Sierra but not in the north. — hike395 (talk) 23:28, 12 April 2024 (UTC)

References

Adopting a policy concerning the relative abundance of less common elements?

A few weeks ago we revamped the table in Abundance of elements in Earth's crust. In discussing those changes, the related problem of the relative abundance of elements in individual or group pages on elements was raised.

As you may know, a determined IP user has been adding unsourced lines like:

• It is the 45th most abundant element in the crust.

to elements like Hafnium, Europium, Erbium ‎and so on and on. These have been reverted. I removed a bunch more over the weekend.

A few pages, eg Lead have sources for relative abundance. The two sources that do give explicit relative abundance are Elmsley "Nature's building blocks : an A-Z guide to the elements" 2011 and Greenwood and Earnshaw (1997). Chemistry of the Elements (2nd ed.) There may be more. I don't know if the numbers in Elmsley vs Greenwood and Earnshaw agree.

I have not found any scientific or textbook discussion of relative abundance, but all of the primary and secondary sources on abundance make the point that the concentrations vary widely. The CRC handbook reports "median" values across multiple sources, saying something like "values of the less abundant elements may vary with location by several orders of magnitude."

In my opinion ranking the less abundant elements is not "knowledge" because the numerical value reported creates an illusion of solidity contrary to the evidence. Unfortunately our options are limited by the sources. For example we can't say "Hafnium is the around the 45th most abundant element in the crust" because that is not what the source says.

Some options for discussion:

1. Status quo. The referenced ranking stay; the unreferenced ones are reverted.
2. Agree that ranking are not notable. Remove the few existing ones. Revert additions.
3. Add Elmsley values with ref but without comment.
4. Add Elmsley values by name, eg "Elmsley reports Hafnium is the 45th most abundant element in the crust.(ref)"

(I picked Elmsley because its available online). While I would prefer to omit this "factoid" and in option 2, I lean to option 4 though I suppose our determined editor will just find some other way to "contribute".

Thoughts? Johnjbarton (talk) 16:22, 15 April 2024 (UTC)

Not being a geologist, I do have the book by Greenwood & Earnshaw, and I don't have any by Elmsley. On the iodine example I can say it does not agree to the other sources that I can consult online. This is what they say about the iodine abundance:

Iodine is considerably less abundant than the lighter halogens both in the earth's crust and in the hydrosphere. It comprises 0.46 ppm of the crustal rocks and is sixtieth in order of abundance (cf. Tl 0.7, Tm 0.5, In 0.24, Sb 0.2).

Wikipedia, on these days, says iodine is the 64th, while having mentioned the Greenwood-&-Earnshaw 0.46 ppm (strange).

On the other hand, a study of 300 various rocks' samples found that the iodine abundance is even lower 0.119 ppm (in continental earth's crust, the surface of which is "contaminated" by constantly cycling iodine from the richer oceanic crust and seawater).

I'm being inclined to the option #2, but not that strict. I would avoid indicating the direct rank, shift focus to the distribution peculiarities, absolute concentrations or relative abundance if possible. To find the optimal path in the complex reference landscape, so to speak.

Tosha Langue (talk) 18:32, 15 April 2024 (UTC)

By the way, I found a source that ranks an element roughly. "[...] lutetium, the scarcest REE (rate earth element), is about the 60th most abundant. But I don't know if it is that reliable.

Yet another thought: an element's abundance rank may provide more sense when viewed along with another metric, characterizing the element's dissemination extent, right? But I don't know if such a measure exists.

Tosha Langue (talk) 08:45, 16 April 2024 (UTC)

There's the Goldschmidt classification, but it's not quantitative. — hike395 (talk) 14:43, 16 April 2024 (UTC)

Yes, thanks, we applied that across the table in Abundance of elements in Earth's crust. Johnjbarton (talk) 16:09, 16 April 2024 (UTC)

All of the comments similar to: "lutetium, the scarcest REE (rate earth element), is about the 60th most abundant" are bogus in my opinion. The scarcity of an element is unrelated to its average concentration in the crust. Many elements are concentrated as pure metals in veins or in ores. Their average concentration may be very low but they can easily be mined and thus are not scarce.

Really the only significance of relative abundance is in relation to cosmology or geochemical cycle. And in those applications we are only interested in orders of magnitude. Johnjbarton (talk) 16:17, 16 April 2024 (UTC)

Bogus. Agree with the estimate! The best I managed to find is Clarke number. Tosha Langue (talk) 18:59, 16 April 2024 (UTC)

References

Late Glacial Interstadial and Bølling–Allerød warming

Are these two articles the same topic? The article on the Bølling–Allerød warming currently begins The Bølling–Allerød interstadial (Danish: [ˈpøle̝ŋ ˈæləˌʁœðˀ]), also called the Late Glacial Interstadial... which implies that it is exactly the same topic as the Late Glacial Interstadial article. If this is the case, then these two articles are clearly duplicates and should be merged. However, reading the academic literature, the term "Bølling–Allerød warming" seems to apply specifically to the sharp warming episode at the begnning of the interstadial, though I am not sure that would warrant a standalone article from the interstadial itself. Hemiauchenia (talk) 20:48, 21 April 2024 (UTC)

I've opened a merge discussion at Talk:Bølling–Allerød_warming. Participate if interested. Thanks. Hemiauchenia (talk) 21:01, 21 April 2024 (UTC)

Monzogranite not in great shape

I found the Monzogranite article filled with too many details and too much jargon. Attempted to clean it up, but it's still missing the "big picture" of what monzogranite is and why it's interesting (if it is interesting). Having an expert in petrology look at it could be helpful. Thanks! — hike395 (talk) 05:59, 9 June 2024 (UTC)

The lead section seems to be based almost entirely on a particular field example, which is not representative. Still trying to find a reliable source for this but apparently 70% of granites are monzogranites. I've opened a discussion on the talk page. Mikenorton (talk) 14:42, 9 June 2024 (UTC)

Thinking more on this, and after looking at the syenogranite article, I would suggest that both of these are simply redirected to granite, which already contains all you need to know about the terms - they're both essentially dictionary definitions with examples. Mikenorton (talk) 17:16, 11 June 2024 (UTC)

Cambrian page

I've added sections and edited others on the Cambrian page and I've 2 requests: One, can someone with more coding nous than me add a ICS (global) subdivisions table cf. Ordovician or Carboniferous please. Gives the info nice and concisely; and two, there are at least two other Cambrian pages that are now obsolete Stratigraphy of the Cambrian and Early Cambrian geochemical fluctuations. Again, could someone with more knowledge of Wikipedian ways delete them. Just to tidy things up. Thx Silica Cat (talk) 15:06, 14 June 2024 (UTC)

The process for obsolete pages is called Wikipedia:Merging and the page gives detailed step by step instructions. It is essentially a review process, so a bit more involved than just tidying up. Johnjbarton (talk) 16:55, 14 June 2024 (UTC)

I've already found that page but I'm not sufficiently familiar with code to follow the process. I prefer to focus my efforts on content creation. The tidying up referred to having potentially obsolete pages on Wikipedia rather than a comment on the process involved. Silica Cat (talk) 17:35, 14 June 2024 (UTC)

Wobbly maths in Template:Infobox geologic timespan?

I applied this template to Bølling–Allerød Interstadial today, after first spotting it at the Allerød oscillation stub (now merged to the Interstadial article.) It's a neat template, but I am not quite sure how it does some unit conversions. I.e. based on Figure 2 of this Nature study, I set the mean CO₂ concentration for 235 ppm - and the infobox automatically wrote that this was 1 times pre-industrial - even though the actual preindustrial CO₂ level was at ~280 ppm.

On the other hand, I tried work backwards for Mean surface temperature parameter. The same figure in the same paper stated that the temperature was ~1.5C lower than the early Holocene mean (which appears practically the same as the preindustrial based on Figure 6 here, so I wanted to set a value that would be described as "2.5 below modern" or thereabouts. Yet, somehow, it didn't work - setting the temperature at 12C results in "2 C below modern", yet 11.5 somehow results in "3 below modern". How does that work?

Lastly, it's probably not a good idea that CO₂ concentration is described relative to preindustrial, yet temperature relative to "modern". It would obviously need regular updates for the foreseeable future to avoid becoming misleading, yet even if those updates are being done, there is no way to tell at a glance whether the temperature value the infobox considers "modern" in fact matches the present-day temperature value (which, lest we forget, continues to rise). InformationToKnowledge (talk) 16:34, 9 June 2024 (UTC)

I fixed the rounding of |CO2= in the infobox --- it will supply one additional significant figure if the concentration is less then 560ppm.

As to temperature, IIUC, the paleoclimate estimates are not accurate to 0.1C, so rounding to the nearest 1C seems wise. I believe by "modern", the infobox means "compared to the global mean of 1961-1990" The term "modern" is ambiguous, but I think making the infobox more wordy would not serve the users. We could add a reference to that paper (although we would then depend on an article having a References section). Pre-industrial mean temperature is probably 13.5C, so it would most likely not make a difference in any infobox, unless the paleotemperature was supplied with 0.1C precision. I would recommend just leaving it alone, but if other Geology editors think it should be changed, will go along with consensus. — hike395 (talk) 17:49, 9 June 2024 (UTC)

Later -- I changed the temperature baseline to 13.5C and displayed the difference to the nearest 0.5C. I'm not convinced that we know paleotemperature averages to 0.5C, so I worry this is WP:OVERPRECISE. Thoughts? — hike395 (talk) 02:17, 10 June 2024 (UTC)

This is much better, thanks! I have added this to Younger Dryas as well now, in addition to B-A Interstadial. Please check if there are any errors (i.e. I just copied the links for Chronological unit and Stratigraphic unit from what Allerød oscillation used to have, but I am not sure if that is accurate?)

I should also say that at least for those two periods, these are temperatures from the geologically recent past, <15,000 years ago, where five different methods of estimating temperature are available. If Nature does not consider their temperature graphs overprecise, who are we to say otherwise?

Yes, I was thinking of temperatures much further in the past. I think 0.5C precision may be a good compromise for all of the different time periods. — hike395 (talk) 22:16, 14 June 2024 (UTC)

At the same time, I have a question about how the "sea level" parameter is coded. You can see it in Figure 3 of the paper I linked earlier, but when I actually tried applying it with "-70" it didn't auto-convert to meters, as I thought it would, nor to any other unit, and instead just kept "-70" next to the Sea level above present day caption. Can we both account for units/negative values and change this line in the template to something more neutral, as we presumably want this infobox to be usable for glacial periods when the sea level was well below the present (or preindustrial, for consistency with the temperature/CO₂ lines?) and not just for the hothouse periods? InformationToKnowledge (talk) 14:50, 11 June 2024 (UTC)

@InformationToKnowledge: |sea_level= may accept non-numeric values (e.g., a call to {{convert}}). In parallel to other infoboxes, I created a new parameter, |sea_level_m=, which accepts only a numeric value and does what you've asked for, above. Feel free to use it. — hike395 (talk) 22:16, 14 June 2024 (UTC)

References

Changing the standard order for Geological periods

In reverting my change @Silica Cat claimed:

• The Geological Period pages have a standard structure

I assume that means Category:Geological_periods. I also infer (because I don't know where the standard policy is) that the "standard structure" puts "Geology" first, but only includes a single section "Stratigraphy", the content actually being chronostratigraphy in a very dry and detailed presentation.

Placing stratigraphy early makes all of the articles dull for normal readers. I'm sure geologists are very excited about stratigraphy, but we should try to make the articles approachable for non-experts. The early parts of the article should be about the most interesting and least technical aspects of a given period. Johnjbarton (talk) 18:18, 14 June 2024 (UTC)

@Johnjbarton @Silica Cat I agree with Silica Cat. First, we have no idea as to whether nongeologists find stratigraphy more boring than paleogeography or vica versa. The best that I can tell this is a personal opinion, which as far as I know, is neither supported nor unsupported by any reliable source. Second, it is "standard structure" / policy in geology as looking at any geological report will show. Third, this "standard structure" is standard because in geology, as in many sciences, the field observations (data), i.e. lithology, fossils, and stratigraphy, are presented before how they are interpreted, i.e age and paleogeography, in a progression from what is directly observed to what is inferred from these observations. Finally, whether it boring or not, putting paleogeography before chronology will confuse people because provides the time frame in which the paleogeography changes over time during the Cambrian. Paul H. (talk) 03:10, 15 June 2024 (UTC)

@Paul H. These are all fine reasons, but completely unknown and unknowable to readers and editors who are not geologist. If the order of presentation is part of the "lesson" of these pages, then include that information in the pages. For example, label the first section "Field observations". Use "Chronology" or "Chronostratigraphy" rather than "Stratigraphy". State early in the article that its organization follows "any geological report". I don't think readers come to Wikipedia to read geological reports, they come to learn about geology. Johnjbarton (talk) 16:05, 15 June 2024 (UTC)

FAC notification

Volcanism of the Mount Edziza volcanic complex is at FAC if anyone is interested in participating. Volcanoguy 15:48, 16 June 2024 (UTC)

Requested move at Talk:Slate Islands#Requested move 14 July 2024

There is a requested move discussion at Talk:Slate Islands#Requested move 14 July 2024 that may be of interest to members of this WikiProject. 98𝚃𝙸𝙶𝙴𝚁𝙸𝚄𝚂 • [𝚃𝙰𝙻𝙺] 22:42, 14 July 2024 (UTC)

Discussion at River

There is a discussion about the proposed content of the River article at the talk page that may be of interest to this project. ForksForks (talk) 13:14, 24 July 2024 (UTC)

RfC: On discovery of the 23 nonmetals

Should this content on the discovery of the 23 nonmetals be removed from the nonmetal article?

RfC is here. --- Sandbh (talk) 00:01, 26 July 2024 (UTC)