Ladies and gentlemen (and others - because I know at least a few geologists who definitely don't fit those categories), for your viewing pleasure:
The view is oblique to the North at about 4 km altitude; because it may turn out to be pretty easy for some people, I'll invoke the Schott Rule. For anyone (like me!) who's new to the game, identify the location of the feature (place name and/or lat and long), and take a swing at what's happening geology-wise. Have fun! (Posted at 7:50 PM Eastern time.)
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12 comments:
I've been following WoGE for a while but it keeps beating me...don't have a clue where.
You all must have seen a lot!
A hint: Really remote areas generally don't have any digital elevation info, so the oblique views look flat.
Of course, if it was really remote, there would be nobody to use the dam...
I've driven past this place- it is halfway between St. George and Zion National Park, Utah. What kind of mine is it?
37.15, -113.42
Hmm...you know, I'm not entirely sure if they do mine anything there. I know from mapping that there's a small landfill and associated buildings, but I can't remember if there's an active mine.
You've got the location nailed; the water body at the top of the feature is the Quail Creek Reservoir, and the whole thing is just to the NE of St. George. But I'm going to be picky and ask for a little geology. It's such a pretty feature, it deserves a description.
(Plus my undergrad advisor would kill me if I didn't push for details, since he's the one who carted me out there on two different field trips.)
and I was looking in Nevada/So. California. It looks like a plunging anticline. But I was wondering about what made the creek turn like it does. Is it just a harder layer at that point? This is my first try at a where on earth so please cut a little slack :)
Awful. I was looking to places in Australia after failing to find something in Nevada. Well, looking forward to #87!
Christie has it! It's the Virgin Anticline, which I've also heard called the Harrisburg Anticline or Harrisburg Dome, although why someone thought it was a dome is beyond me. It's cored by Kaibab Limestone, with the Moenkopi and Chinle Formations "above" that.
Christie, you're right about the harder layer. The Virgin River doesn't cut through the fold because it's flowing over the base of the Chinle Fm, which is called the Shinarump Member and made up of resistant river deposits (well-cemented sand and cobbles, for the most part). (Yep, that's a river. Out West, they call things rivers that I would barely qualify as a creek, but that's the way it is.)
All right, all those replies are enough to satisfy the challenge. Chuck was the first to nail the location, so he's going to be hosting WoGE #87. Kudos to Christie for identifying the structure!
You want details? How about this: a panorama of a roadcut within the WoGE #86 field of view. View the large size for the most detail.
I wanted to e-mail you this while I was under the Schott Rule induced gag, but I couldn't find any contact info on the site. You can see that the photo is geotagged on the Flickr site - I had to wait to reply to Marli Miller's comment for fear of giving away the location of the WoGE challenge.
So was this part of your undergrad field camp or do you know the area from driving by on the way to Zion?
Where on (Google) Earth number 87 is up here.
btw, Tuff, WoGE generally runs a bit more smoothly if you turn moderation off for the duration of the contest. I have no idea if 87 will be solved by the time this comment appears, for example.
Ron - lovely photo! I've been out there twice; once for a field camp my freshman year and this past May during the Rocky Mountain GSA meeting. I have fond memories of that roadcut (well, fond in retrospective. As a freshman I knew pretty much squat about field mapping and I was pretty frustrated at the time. Needless to say, the second visit was much nicer.)
Chuck - Thanks for the advice. I'm always grateful for help getting into new things, especially online. I figure I'll just turn off comment moderation completely, since it's such a small audience here.
Looks like #87 is still up for grabs!
PS - Email's up too!
Quail Creek dam failed in 1988 because gypsum-karst layers in the Shnabkaib Member were dissolved by lakewater and undermined the dam structure.
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