Talk:Geology of the Grand Canyon area

Old talk

Hi Mav, re the centre/right thing, I disagree, but not enough to want to argue about it - if we are going to center it, why don't we go the whole way and make it as wide as we can? I know, I know, but the Grand Canyon is perhaps the only page that would really justify this kind of treatment! Mark Richards 20:12, 28 Apr 2004 (UTC)

We are limited by what people with 800x600 screens can see. --mav

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I removed this from the Grand Canyon page - I think its all covered here. Wow - there is SO much work to do on this still! Let's go! Mark Richards 19:34, 28 Apr 2004 (UTC)

The strata, from the bottom to top, are:

   * Early Proterozoic Schist and Granite: 1.7 billion years ago
         o Vishnu Schist 
   * The Earlier Unconformity: 1.7 to 1.25 billion years ago
   * The Middle and Late Proterozoic Grand Canyon Supergroup: 1250 to 820 million years ago
         o The Uncar Group
         o Bass Limestone
         o Hotauta Conglomerate
         o Hakatai Shale
         o Shinumo Quartzite
         o Dox Sandstone
         o Cardena Lavas 
   * Nakoweap Formation: 1 billion years ago
   * The Chuar Group: 950 million years ago
   * The Sixtymile Formation: 820 million years ago
   * The Great Unconformity: 820 to 570 million years ago
   * Paleozoic Sediments: 570 to 245 million years ago
   * The Cambrian Tonto Group: 570 to 505 million years ago
   * A Pre-Devonian Unconformity: 505 to 360 million years ago
   * Devonian Deposits: 408 to 360 million years ago
         o Devonian River Channels
         o Temple Butte Formation 
   * The Redwall Limestone: 360 to 320 million years ago
         o Surprise Canyon Formation 
   * The Supai Group: 320 to 286 million years ago
         o Watahomigi
         o Manakacha
         o Wescogame
         o Esplanade 
   * The Hermit Shale: 286 to 245 million years ago
   * Coconino Sandstone
   * The Toroweap Formation
   * The Kaibab Formation
   * Mesozoic Geology: 245 to 66 million years ago
         o Shinarump Conglomerate
         o Moenkopi Formation
         o Chinle Shale
         o Chinle Formation
         o Moenave Formation
         o Kayenta Formation
         o Navajo Sandstone
         o Caramel Sandstones
         o Entrada Sandstones
         o San Rafael Group
         o Dakota Sandstone

Yep - still a lot to do. --mav

Invisible references

Invisible references via the Inote template (see talk page) are now implemented in this article. Your comments appreciated. Mozzerati 21:44, 2005 Apr 20 (UTC)

Should there be any talk about the current controvery over the grand canyon's age?

These articles suggest that there may be some controversy in the government's stance on the geological age of the grand canyon.

[1] [2] —The preceding unsigned comment was added by Chrisdab (talk • contribs) 22:23, 6 January 2007 (UTC).

See the discussion at Talk:Grand_Canyon. The fact that the government may choose to ignore science does not mean that the age of the Grand Canyon is controversial. Geologyguy 22:37, 6 January 2007 (UTC)

There is more then one theory on how the Grand Canyon formed. And this also includes differences in the age of the Grand Canyon. If someone has literature, please show it here. --41.18.46.57 (talk) 07:39, 11 July 2009 (UTC)

If you have a reliable source about any other geological estimates of the age of the canyon, please mention it. But I'm pretty sure that the ice age is the only valid theory for it's formation. Auntie E (talk) 13:08, 11 July 2009 (UTC)

Canyon formation likely went faster during the ice age due to increased precipitation but I would not say that it caused the canyon's formation. Rather, downcutting of the Colorado River as the Colorado Plateau rose and the Gulf of California opened up is the consensus view. --mav (talk) 02:23, 31 August 2009 (UTC)

A tempest in a young-Earther crackpot does not a scientific controversy make. --mav (talk) 02:23, 31 August 2009 (UTC)

There is certainly scientific uncertainty over the exact age of the Grand Canyon as evidenced by the ongoing research. The NPS Grand Canyon website contains lots of scientifically valid information and I could find no hint of a younger age for the canyon. The statement is made on the website that the canyon is 5-6 million years old and shows new and older rock formations with ages of a few hundred million to billions of years old. I was just at the canyon a few weeks ago. I guess I should have polled the employees for an age estimate :). Desoto10 (talk) 01:04, 17 September 2009 (UTC)

From what I've read, it is much more an issue of definitions; Did something we know as the "Grand Canyon" exist prior to 5 to 6 million years ago? Well, it depends on whether or not you call one or the other of the (at least) two ancestral canyons that eventually merged, the "Grand Canyon" or not. IMO, the Grand Canyon did not exist until the merger and we have a ballpark figure for when that happened. Unfortunately, much of the downcutting prior to 5 to 6 million years ago occurred in Mesozoic-aged strata that have since been almost completely removed from the Grand Canyon area. Much was also carried away by expansion of the canyon itself. Pitty. I would love to know where the upper canyon emptied and exactly how the merger happened. --mav (talk) 13:02, 20 September 2009 (UTC)

Why name it 'Vishnu Schist'?

What about the history of the names given to various layers? Especially, the 'Vishnu Schist', whats the origin of this name? 'JB, 15-May-2007, Australia'

Most geological formation names are based on some local geographic feature in the area where the rock unit was described. I know there is a Vishnu's Temple in the Grand Canyon, and maybe other similarly named locations. Many of the geographic features, including many with names from Hindu theology such as Vishnu, Shiva, and Krishna, were given by USGS explorer Clarence Dutton in 1880-81. Hope this helps. Cheers Geologyguy 02:11, 15 May 2007 (UTC)

Also, Zoroaster, as in the Zoroaster Granite, is a prophet from the religion Zoroastrianism.

In almost all cases, that info is more appropriate in articles about the individual formations. --mav (talk) 02:24, 31 August 2009 (UTC)

Photo not of a crinoid?

In the section "Hermit, Coconino, Toroweap, and Kaibab", there is a photograph with the caption "Fossils, such as this one of a crinoid, are common in the Toroweap and Kaibab formations". The predominant feature in the photo looks like the pedicle valve of a Productid brachiopod. Although there might be some crinozoid stems in the photo, I think the caption should be changed to "Fossils, such as this one of a brachiopod...". Or am I just missing something? —Preceding unsigned comment added by Sonomadiver@gmail.com (talk • contribs) 21:39, 6 July 2010 (UTC)

You're not missing anything, the original source of the photo confirms that the large fossil is a brachiopod. I'll modify the caption accordingly. Thanks for spotting that. Mikenorton (talk) 22:17, 6 July 2010 (UTC)

Thanks for the feedback! - sonomadiver