Friday Field Foto #9: Igneous intrusion cutting across folded strata
This week…another photo from Chile.
Cretaceous Tres Pasos Formation cross cut by Miocene intrusions (©2009 clasticdetritus.com)
Here we got a good ol’ geologic puzzle…the kind you’d learn in an intro class. Here we can use the intuitive law of cross-cutting relationships to determine the relative timing of events. First the sediments were deposited, then the lithified sediments (rocks) were uplifted and folded, then an igneous intrusion cuts across the fold. Finally, erosion reveals it all for us to see.
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To see all the Friday Field Fotos, go here.
To see more photos of Patagonia, go here.
NHL All-Star Game
I didn’t watch the game…all-star games or pro bowls are kind of useless in a way. But, I’m pretty psyched that my team, the Buffalo Sabres (where I grew up), was well represented. Daniel Briere had 1 goal and 4 assists and was named MVP.
The Sabres have never won the Cup. They made it in ’99 only to be defeated by the Dallas Stars in game 6. Before that, they haven’t been in the finals since the early ’70s. This could be the year…they are second in the league, first in the eastern conference (standings). Typically there’s a couple teams that kick ass in the regular season and then s#@t the bed in the first round of the playoffs. That would suck.
Southbound Sand
I love sediment (I even like how it settles at the bottom of a cup of Turkish coffee). I figured the least I can do on this blog is comment on sediment in the news.
A few days ago the BBC published this article on their website about the shifting sands of the Sahara. The sand dunes are slowly, but surely, advancing their way south and pushing communities in Nigeria out of their way.
“What we do is that when the sand moves and buries our homes and farms and even our wells, we simply keep retreating southwards”
One of the issues, is that the villagers are continuously cutting down trees for firewood, which is opening a clear path for the sand to migrate through.
What to do about it? Well, there’s not too much, especially for remote communities struggling to get by as it is. In other areas engineers have tried sand fences with limited success. Check out this article that discusses the mechanics of dune migration in a little more detail.
Photograph from www.sahara-photo-tour.com
Where on (Google)Earth #2
Alright…let’s try another one.
If you want to play…go here to find out what I’m talking about.
UPDATE (1/28/2007):
Apparently, the watchdog group called PEER (Public Employees for Environmental Research) that originally put out the press release I linked to in the original post (see below) was either not being totally honest or there is some miscommunication somewhere.
Skeptic magazine reported on this story but when they started looking into it further, they figured out they were “duped” by PEER. Read statement from Michael Shermer, editor of Skeptic magazine, here.
A reader of Skeptic who contacted PEER had this to say:
“When I challenged that PEER guy to show me some evidence and provided him evidence to the contrary, he didn’t have much. I would say PEER did more than jump the gun. I’d say they are spreading misinformation.”
It is really unfortunate that PEER had to do this. From their website it appears they do some important, relevant, and honest activism. Unfortunately, this kind of tom-foolery really takes a bite out of their credibility as a “watch dog”.
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ORIGINAL POST (1/21/2007):
Please read this regarding the unsettling happenings within the National Park Service (NPS) and how to inform park-goers how old and by what processes the Grand Canyon formed.
“In order to avoid offending religious fundamentalists, our National Park Service is under orders to suspend its belief in geology,” stated Public Employees for Environmental Research (PEER) Executive Director Jeff Ruch. “It is disconcerting that the official position of a national park as to the geologic age of the Grand Canyon is ‘no comment.’”
The presence of the book for sale in the visitor center bookstore that lays out (presumably) how Noah’s flood was responsible for both the deposition of the ancient sediments exposed in the canyon AND the carving of the canyon is bad enough.
What’s funny is how this administration made a big deal last year about the ‘American Competitiveness Initiative’ to help increase the quality of science and technology-related education. This is how they do it?! How does promoting this absolute fantasy enable Americans to be more competitive?
“As one park geologist said, this is equivalent of Yellowstone National Park selling a book entitled Geysers of Old Faithful: Nostrils of Satan,” Ruch added,
Here’s the letter from the park employees to the NPS director expressing their distaste for this non-scientific malarkey.
Thanks for the link, KS
Photograph above taken by me in summer of 2006.
Friday Field Foto #8: Cretaceous shoreline deposits
I’ve missed the last few Fridays…
The Book Cliffs are in central Utah and western Colorado and are famous for their spectacular outcrops of Cretaceous shoreline deposits. The seaway, which once stretched across the whole of North America from the Gulf of Mexico to the Arctic Ocean, left a fantastic record of relative sea level changes in these sedimentary rocks. The landward or basinward movement of the shoreline can be mapped along the Book Cliffs by identifying the various sedimentary environments (coastal plain, beach, shoreface, shelf, etc.) in the record.
The map above illustrates this paleogeography nicely. Note how much of Colorado is part of this seaway at this time. Eventually, the rivers and shorelines (as recorded by the stratigraphy) march across Colorado too. This image taken from a fantastic website by geologist Ron Blakey at the University of Northern Arizona. Check it out.
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Where on (Google)Earth #1?
Okay…here’s an idea. Every once in a while I’m going to grab an image of somewhere on this planet using GoogleEarth. It’s up to the readers to determine or guess where it is. It will usually, although maybe not always, be a natural feature of the Earth that is highlighted. Sometimes I might be zoomed in, other times it’ll be a wide shot. Sometimes it might have something to do with an area or phenomenon discussed in the news…sometimes not.
If you can’t tell me exactly where it is…then tell me something about the natural feature that is shown.
If you get it right….well, that’s it, you get it right….i’m not gonna give you a prize or anything. Who do you think I am?
Check out this blog for a similar GoogleEarth type of thing in quiz form.
The first image might be easy for some….
Click on image to see larger version
Awesome jazz and groove podcast
For those podcast subscribers out there, I found a great monthly music show that highlights groovy jazz
(including all the sub-sub-sub-genres of acid jazz, afro-beat, bop, cool jazz, cosmic jazz, dub, downtempo, electro-jazz, fusion, future jazz, groove jazz, jazzatronic, jazz dance, jazz-funk, jazz-rock, kozmigroov, modal, phusion, progressive, modern, nu-jazz, soul-jazz, spiritual, and world).
It’s called BendingCorners and is nice because the creators are DJs who spin sets that are about an hour or a little more of continuous music (i.e., one, long audio file)…typically within a ‘theme’ for that month. You can either subscribe to the podcast or just download the files directly. Although they only come once a month, if you like it, you can download from the archive. If you get really into it (I wish I had the time), they have the playlists for each set and you can explore the original stuff.
If jazz and groove is not your thing, you should at the very least download the tribute to James Brown (the Dec 2006 set called ‘Mr. Dynamite‘).
Expanding Spheres
The geoblogosphere…at least from my limited perspective…is expanding today. Fellow bloggers of mostly geo-related topics are linking to each other. Check out the list on the sidebar called ‘Earth Science Blogs’ from time to time…I will be adding more and more.
Special thanks to Highly Allochthonous for getting this going…check it out.
Image at right here.
Procrastination
In an effort to not do any work, but still sit at a computer pretending i’m working…i’ve spent time updating and modifying this blog with a new look and more links at the side.
A fellow geo-geek from Stanford (now a post-doc at Syracuse) has a nice blog called Apparent Dip … check it out.
Clastic Detritus 
