Talk:Permian–Triassic extinction event

Chart at the top of the article

I think the caption for this chart might need a little more explanation. Can the vertical axis be labelled? I can infer the trend indicated in the chart, but I can't say I know exactly what it is saying. Regards, PDCook (talk) 17:26, 27 March 2010 (UTC)

Picture of supercontinent and areas marked

The supercontinent picture is a bit misleading because the text next to it says that the continents are labelled. However, Australia is missing. Also, India, which is a nation and not a continent, is labelled. Is there a way to fix this? —Preceding unsigned comment added by Montreux (talk • contribs) 05:03, 19 April 2010 (UTC)

There is no problem with that picture, 1. Australia is there, 2. India is also a geological continent. Rursus dixit. (^mbork³!) 20:01, 14 June 2010 (UTC)

Copyright problem removed

One or more portions of this article duplicated other source(s). The material was copied from: (see below). Infringing material has been rewritten or removed and must not be restored, unless it is duly released under a compatible license. (For more information, please see "using copyrighted works from others" if you are not the copyright holder of this material, or "donating copyrighted materials" if you are.) For legal reasons, we cannot accept copyrighted text or images borrowed from other web sites or published material; such additions will be deleted. Contributors may use copyrighted publications as a source of information, but not as a source of sentences or phrases. Accordingly, the material may be rewritten, but only if it does not infringe on the copyright of the original or plagiarize from that source. Please see our guideline on non-free text for how to properly implement limited quotations of copyrighted text. Wikipedia takes copyright violations very seriously, and persistent violators will be blocked from editing. While we appreciate contributions, we must require all contributors to understand and comply with these policies. Thank you. J. Spencer (talk) 00:08, 21 October 2010 (UTC)

While checking some rewording, I found that two chunks of text were copy-and-paste jobs, mostly from http://math.ucr.edu/home/baez/extinction/, but with some lines from http://www.santafe.edu/media/workingpapers/99-12-079.pdf woven in as well. What appears to have happened is the article The Big Five was merged to several extinction pages in September 2008 (in this page's case this edit) without it being known that the merged article was a copyvio.

After considering, I removed the chunks that were copyvios instead of rewriting as the first chunk was largely redundant with other text, and the second chunk had been slightly modified and was no longer accurate. J. Spencer (talk) 00:08, 21 October 2010 (UTC)

How sure are you about this? I know the Baez site has borrowed significantly from Wikipedia in the past (and hence the copying might go in the other direction). In addition, someone who appears to have a vested interest in that site has on various occasions added material to Wikipedia, so it may have been added by the copyright owner. So I'd want to look closely before declaring an infringement. Of course, if it can be rewritten / replaced / removed without harming us then that is probably all for the best regardless. Dragons flight (talk) 00:21, 21 October 2010 (UTC)

Here's a random pre-July 2008 (when "The Big Five" was started here) pull from Internet Archive; and here is the site today. The text for the Permian-Triassic, Late Devonian, and Ordovician extinctions are exactly the same as they are now, so the Baez site has to be the originator in this case. J. Spencer (talk) 00:31, 21 October 2010 (UTC)

impact event?

What about the Hudson Bay impact? It is certainly large enough to have caused a mass extinction on a scale far exceeding the demise of the dinosaurs. Does anyone know when the Hudsom Bay impact occurred? —Preceding unsigned comment added by 76.28.177.80 (talk) 16:02, 23 October 2010 (UTC)

If a person takes the time and effort to read through and look at the numerous detailed papers and geologic maps that has been published by geologists and other Earth scientists for the Hudson Bay shorelines and region, they would find that there is more than enough hard data to completely refute any ideas about the Nastapoka Arc being part of enormous extraterrestrial impact structure. The fact of the matter is that many geologists have looked long and hard for any evidence of impact deformed and brecciated rock, shocked quartz, shatter cones, high pressure mineral polymorphs, impact melt sheets and/or dikes, and impact-related pseudotachylytes associated with the Nastapoka Arc. Despite repeated efforts to find it by geologists and expectation that it would be found, such evidence has been found to be completely absent. Instead, they have found that local and regional structure, stratigraphy, and other aspects of the geology of the Nastapoka Arc soundly refute the theory that it was created by an extraterrestrial impact and solidly demonstrate the fictional and imaginary nature of a hypothesized "Hudson Bay Impact." The question about the age of the "Hudson Bay Impact" lacks any answer because the "Hudson Bay Impact" never occurred in the first place. When looking at Hudson Bay and Nastapoka Arc with Google Earth, a person has to understand that there are many other geological processes in addition to extraterrestrial impacts that are capable of producing arcuate geological structures and landforms. Go look at:

1. 2. Is there a large impact structue on the SE margin of Hudson Bay, Canada?

2. Eaton D. W. and F. Darbyshire, 2010, Lithospheric architecture and tectonic evolution of the Hudson Bay region. Tectonophysics. v. 480, pp. 1–22.Paul H. (talk) 05:28, 24 October 2010 (UTC)

Using abbreviations without explanations.

for instance - what the fuck is "Ma"?

However, a study of uranium/lead ratios of zircons from rock sequences near Meishan, Changxing, Zhejiang Province, China[3] date the extinction to 251.4 ±0.03 Ma, with

Ma is "megaannum", or "million years". It's got a metric prefix, and is slightly more flexible than "million years ago" because the "ago" isn't explicitly part of the name (i.e., you can use it for comparisons, like "A was found in rocks 6 Ma older than B", which is clumsier when you've got to work around "ago"). J. Spencer (talk) 00:32, 18 November 2010 (UTC)

"Mya" is much clearer. --Michael C. Price ^talk 01:05, 18 November 2010 (UTC)

I don't have a horse in that race; I'm just happy when people pick one and stick with it! J. Spencer (talk) 01:16, 18 November 2010 (UTC)

Having said that, the article uses both formulations, and really ought to be standardized. J. Spencer (talk) 17:03, 20 November 2010 (UTC)

Impact Origin of the Gulf of Mexico

The AAPG essay / commentary, Stanton (2002), about the Gulf of Mexico being an impact crater is not only very speculative, but it is also very badly flawed and sloppy in terms of its scientific content and interpretations. It relies too heavily on very dated, if not antiquated, reference material, including a 1979 textbook. This essay simply ignores the overwhelming number of more recent peer-reviewed publications that contain geophysical and geological data and research that soundly refute specific interpretations made by it along with the idea Gulf of Mexico being an impact crater. For example, Viele et al. (1989) and Nichlas et al. (1989) summarizes decades of research that readily refutes the idea that either fold belts of the Ouachita orgeny or the metamorphism of their associated Paleozoic rocks could have possibly been created by an asteroid impact of any magnitude. They are the result of nonimpact tectonic processes that not only acted over tens of millions of years but also started hundreds of millions of years before the Permian–Triassic extinction event. In another case, there exists ample published geophysical and geological research, as summarized by Goldthwaite (1991) and Sawyer et al. (1991), that demonstrates that the central uplift, which Stanton (2002) claims to exist in the center of the Gulf of Mexico, is completely imaginary. The idea that the Gulf of Mexico is an impact basin and that there are seriously problems with a plate tectonic explanation of its origin is a dead issue among geologists in general as illustrated by the papers by Dickinson and Lawton (2001) and Galloway (2008). Stanton (2002) is so extremely badly researched and argued that it fails to provide a credible case for the Gulf of Mexico being an impact crater.

References Cited:

Dickinson, W. R., and T. F. Lawton, 2001, Carboniferous to Cretaceous assembly and fragmentation of Mexico. Geological Society of America Bulletin. v. 113, no. 9, pp. 1142–1160.

Goldthwaite, D., ed., 1991, Introduction to Central Gulf Coast Geology, New Orleans Geological Society, New Orleans, Louisiana.

Galloway, W. E., 2008, Depositional evolution of the Gulf of Mexico sedimentary basin, in K.J. Hsu, ed., pp. 505-549, The Sedimentary Basins of the United States and Canada, Sedimentary Basins of the World. v. 5, Elsevier, The Netherlands.

Nicholas, R. L., and D. E. Waddell, 1989, The Ouachita system in the subsurface of Texas, Arkansas, and Louisiana, in R. D. Hatcher, Jr., W. A. Thomas, and G. W. Viele, eds., pp. 661-672, The Appalachian-Ouachita Orogen in the United States: The Geology of North America, v. F-2. Geological Society of America, Boulder, Colorado.

Sawyer, D. S., R. T. Buffler, and R. H. Pilger, Jr., 1991, The crust under the Gulf of Mexico basin, in A. Salvador, ed., pp. 53-72, The Gulf of Mexico Basin: The Geology of North America, v. J., Geological Society of America, Boulder, Colorado.

Stanton, M. S., 2002, Is the Gulf's Origin Heaven Sent? American Association of Petroleum Geologists. Tulsa Oklahoma. [Stanton (2002) PDF file], [Stanton (2002) Web Page]

Viele, G. W., and Thomas, W. A., 1989, Tectonic synthesis of the Ouachita orogenic belt, in R. D. Hatcher, Jr., W. A. Thomas, and G. W. Viele, eds., pp. 695-728, The Appalachian-Ouachita Orogen in the United States: The Geology of North America, v. F-2. Geological Society of America, Boulder, Colorado

Science News resource

Acidifying oceans helped fuel mass extinction; Great die-off 250 million years ago could trace in part to waters' change in pH by Alexandra Witze October 8th, 2011; Vol.180 #8 (p. 10) Science News 99.35.15.199 (talk) 00:55, 10 October 2011 (UTC)

It would be better to consult the full paper instead a popular science article. The paper discussed in this article is:

Montenegro, A., P. Spence, K. J. Meissner, M. Eby, M. J. Melchin, and S. T. Johnston (2011), Climate simulations of the Permian-Triassic boundary: Ocean acidification and the extinction event. Paleoceanography. vol. 26, no. PA3207, 19 pp. doi:10.1029/2010PA002058. Paul H. (talk) 11:59, 10 October 2011 (UTC)

paper published online August 2 in Paleoceanography per link. 97.87.29.188 (talk) 20:55, 10 October 2011 (UTC)

Algeo et al.

A NSF press release announces a paper by Algeo et al. which will be relevant to this article: presumably time is needed for evaluation. . dave souza, talk 09:25, 21 February 2012 (UTC)