Wednesday, May 28, 2008

Annotated photos from Glacier NP

Cleaning up my hard drive today, before switching over to the laptop for my summer travels. Thought I would share a few annotated photos from my "Geology of Glacier National Park and surrounding areas" class that I took last summer.

Here's Chief Mountain:
chief_mtn

On the trail to Firebrand Pass, here's the contact between the Altyn Formation (lowest of the Belt Supergroup exposed at Glacier) and the overlying Appekunny Formation:
altyn_appekunny

The Purcell Sill is a readily recognizable feature high on the glacially-carved walls of Glacier National Park. This shot is from the trail on the way up to Grinnell Glacier:
sill

Here's a shot from Sun River Canyon, showing one of the many imbricate thrust faults there, with some glacial till thrown in as a bonus feature:
fault

Just outside of Sun River Canyon, we saw some nice recumbent drag folds on some thrust faults in the Cretaceous rocks:
recumbent_anticlines

This one was from early in the trip, on the road from Helena up north towards Glacier. Specifically, we stopped in Little Prickly Pear Canyon, near Wolf Creek, and saw these chevron folds in the Cretaceous rocks there:
anticlines

Along those same lines (folded Cretaceous strata), here's a gorgeous fold just outside the park's boundary, on the road leading north from Two Medicine towards Many Glacier:
big fold

No annotations on this one, but I wanted to share it anyhow: a blind thrust / drag fold complex, in the Grinnell Formation (exposed on the trail up to Grinnell Glacier):
blind_thrust

Lastly, some snow photos. I took this shot on my way up the trail to Grinnell Glacier, because the holes in the snow reminded me of the scary mask face from the Scream movies. But then on the way down, I realized I had the opportunity to document how much snowmelt occurs in six hours of Glacier NP summer weather. Hence, the bottom "after" shot:
snowmelt

That's it for today... Enjoy!

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5 Comments:

Blogger Erik said...

Does anyone else find it a little annoying when someone draws directly on a picture? It makes it impossible for the viewer to interpret it as anything but what is in the drawing.

Not that the interpretation is wrong or anything, it's just very hard to notice anything but the parts that are marked up. :-)

May 28, 2008 10:41 AM  
Blogger Silver Fox said...

I was just going to say - GREAT photos, and thanks for drawing on them and labeling them!

May 28, 2008 12:03 PM  
Blogger geobabe said...

Stop with the sexy Glac photos already! You're such a tease :) May I add a note about the Altyn Fm? It is a pre-critter limestone...therefore a chemical precipitate and hence no fossils.

May 28, 2008 1:48 PM  
Blogger Callan Bentley said...

Hey there all,

Erik, happy to share the unsullied versions too. But the reason I marked this up was to make teaching images.

Silver Fox, thanks!

Geobabe, ALL of the Belt Supergroup is pre-critter. It's Mesoproterozoic, and even the Ediacarans (first fossils I could characterize as "critters") don't show up until the Neoproterozoic.

Thanks for the feedback, all.

CB

May 28, 2008 1:58 PM  
Blogger Baron Snorri said...

Nicely done! The super-photo markings do assist those of us who are a little out of practice.

May 29, 2008 5:13 AM  

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