Talk:History of Earth/GA2

GA Review

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Reviewer: Sasata (talk · contribs) 16:05, 5 February 2012 (UTC)

I will review this article. Before we get started, could the nominator make sure that all paragraphs and end-of-paragraph sentences are cited to make it easier for me to verify the text. I'll provide a detailed review after this is completed. Sasata (talk) 16:05, 5 February 2012 (UTC)

Could you clarify that? Do you want every single paragraph (including those in the lead) and every sentence at the end of each paragraph, to have citations? Could you name specific ones? To the best of my knowledge the information is sufficiently cited which is why I nominated it in the first place, but I may have missed some areas. I purposely left the lead uncited because it is clarified in the body. Cadiomals (talk) 19:25, 5 February 2012 (UTC)

As I said, all paragraphs and end-of-paragraph sentences need to have a citation, not including the lead, and not if the information is so obvious that it's unlikely to ever be challenged (even then, "obvious" is subjective, so it's better to add a citation when in doubt). Check out WP:Citing sources. If you'd like, I can add citation needed tags throughout, but it should be straightforward if you follow the guidelines. Sasata (talk) 19:32, 5 February 2012 (UTC)

I have gone through the whole article, added citations where I felt necessary (as well as doing some copy-editing), and feel as though there are a sufficient amount. There aren't necessarily citations at the end of every paragraph but almost every paragraph contains citations. If there's a problem just specify it. Cadiomals (talk) 00:08, 6 February 2012 (UTC)

Comments up to subsection "4.0 Ga: The first continents"

• should pick either American or British English spelling and make it consistent throughout  Done RockMagnetist (talk) 21:02, 17 April 2012 (UTC)
• "The Moon has a bulk composition closely resembling the Earth's mantle and crust together, without the Earth's core." should this be started with something like "Based on analyses of surface rock samples, "? Done
• "Immediately after the impact, the Earth's mantle was vigorously convecting, the surface was a large magma ocean." grammar problem (missing a word?) Done
• the frequent use of "must have" bugs me; it sounds (to me) like the text is trying too hard to convince the reader that the facts are true, e.g.:

"cooling must have occurred quickly"

"so convection in the mantle must have been faster."

"a solid crust with a basaltic composition must have formed." Done

• "during the early Archaean (about 3.0 Ga) the mantle was still much hotter than today" Done
• "This means the fraction of partially molten material was still much larger than today." Done
• "The large amount of water on Earth can never have been produced by volcanism and degassing alone." the phrase "can never have been" sounds odd to me; how about "could not have been" or "was not"? Done
• "Free oxygen would have been bound by hydrogen or minerals on the surface." source? Done (got rid of it, not really needed)
• "Most geologists believe that during the Hadean and Archaean, subduction zones were more common, and therefore tectonic plates were smaller." I don't see the part which supports the statement "Most geologists believe" Done
• the external links in refs #3 (Levin 1972), #5 (Chaisson 2005), and #17 (Britt 2002) have gone dead Done
• ref #7 Wethergill 1991 has odd formatting unlike most of the others (same for 20, 21, and others later) (p.s. reference formatting minutiae is beyond the requirements for GA, so you can ignore this if you like; I like to have "clean" references, however, and will clean them up anyways later if you don't care to); I see that some sources are repeated in the "References" and in the "Literature" sections, and some of the sources listed in Literature don't appear to have been cited. Done
• what makes refs #10 (Universe today), #34 (about.com), and #36 (eNotes) reliable sources?  Done - removed RockMagnetist (talk) 06:02, 15 April 2012 (UTC)
• I cannot see where in ref#4 supports the statement that "…the solar nebula began to contract, possibly due to the shock wave of a nearby supernova." (I may have missed it; there's lot of distracting physics and fancy equations in this source) Also, where does it say the protoplanets are up to several kilometres in length?

 Done I found a ref that supports it. RockMagnetist (talk) 18:19, 13 April 2012 (UTC)

• refs #10 does not support the statement "During the accretion of material to the protoplanet, a cloud of gaseous silica must have surrounded the Earth, to condense afterwards as solid rocks on the surface." Nor can I verify "This changed when Earth accreted to about 40% of its present radius"  Done - removed this material RockMagnetist (talk) 05:47, 15 April 2012 (UTC)
• I don't see where ref #12 supports the statement "During the Hadean, the Earth's surface was under a continuous bombardment by meteorites, and volcanism must have been severe due to the large heat flow and geothermal gradient."  Done RockMagnetist (talk) 16:20, 15 April 2012 (UTC)
• I can't find in ref #23 (Liu, 1992) where it verifies the speed range (8–20 km/sec) given for impacting Theia (it does give 5 km/sec, though)  Done - modified text and added ref RockMagnetist (talk) 05:45, 14 April 2012 (UTC)
• where does ref #26 support "The radiometric ages show the Earth existed already for at least 10 million years before the impact" or "The planet's first atmosphere must have been completely blown away by the impact."?  Done - removed paragraph. RockMagnetist (talk) 19:00, 16 April 2012 (UTC)
• where does ref #28 support "Because the Earth lacked an atmosphere immediately after the giant impact, cooling must have occurred quickly." or "Within 150 million years…" or "The felsic continental crust of today did not yet exist." or "… the mantle was still much hotter than today, probably around 1600 °C." or "Steam escaped from the crust"?  Done RockMagnetist (talk) 05:22, 18 April 2012 (UTC)
• how does ref#27 support "It is, however, assumed that this crust must have been basaltic in composition, like today's oceanic crust, because little crustal differentiation had yet taken place."?  Done RockMagnetist (talk) 05:22, 18 April 2012 (UTC)

Response

I will look at all your points and try to fix as much as I can. This may take a while since I'm in the middle of a bunch of other articles.

About the references, a lot of them refer to the paragraph they were in as a whole, rather than the sentences they immediately come after. That might be something to keep in mind. When you said you wanted a citation at the end of every paragraph, I actually transferred some of them to the end of the paragraph, seeing a lot of the information in them can actually apply to the paragraphs as wholes.

Also, I'm not entirely sure of the distinction between good vs. featured article criteria, but it seems like a lot of what your asking borders on featured article criteria. Especially since you are only on the first section and have already given me quite a bit and there are several more sections to go, I fear you may hit me with a ton more precise criticisms.

Once again, I'll try to fix what I can, such as the grammar/prose problems. As for the citations, a lot of those were not added by me, so I'm not entirely sure I can fix that, but I'll see what i can do.

Cadiomals (talk) 17:03, 9 February 2012 (UTC)

Please see criterion 2; I plan to check all of the citations that I can access. This is an important, highly-viewed article, and I can't in good conscience pass it as GA unless the sourcing is top-notch. I'll try to leave nitpicky prose and MoS concerns to a minimum, or fix them myself (the prose looks pretty good anyway, from what I've read so far.) Sasata (talk) 17:26, 9 February 2012 (UTC)

Additional comments: Actually, I think your prose and grammar feedback would be a great help. It may sound nitpicky but I don't mind because those things are relatively easy to fix (as opposed to, say, fixing citations) and will improve the overall quality of the content. Cadiomals (talk) 01:26, 10 February 2012 (UTC)

I've looked more at the article, and have decided to fail this review. I think there's too much that needs to be referenced for this to be able to meet criterion 2 (Factually accurate and verifiable) in a suitable time frame. In addition to the needed citations and failed verifications listed above, I've added a number of citation needed tags to statements or paragraphs that needed them. There are more minor prose and MoS tweaks that could be made, but it seems pointless to attend to the fine details when sourcing is not yet up to par. The numerous deadlinks also need to be fixed before the next review. Hope these comments have been useful, Sasata (talk) 04:11, 25 February 2012 (UTC)

Thank you for your feedback Sasata, it is greatly appreciated. Unfortunately I have not had time recently to seriously devote to finding sufficient references for this article, but tagging them where they're needed definitely helps. That's the number 1 reason it failed the last two nominations: the sources were insufficient. Hopefully in due time this problem will be fixed, and it can always be nominated again. It would help just as a final favor if you could go through the entire article and tag wherever a citation is needed (you did this partially) and also tag dead links. Cadiomals (talk) 16:08, 25 February 2012 (UTC)

 Done I have fixed all the dead links. RockMagnetist (talk) 17:43, 13 April 2012 (UTC)