Callan Bentley Tension gashes are small veins that open up when rocks get stretched. Often, they are arrayed en echelon with respect to other tension gashes, all oriented in the same direction. Here is a sample of tension gashes I found this summer in rip-rap (i.e., not in situ) at some building site in New England. (I … Read more
This is the second of my Rockies course student projects that I wanted to share here on the blog: it is a guest post by Filip Goc. Enjoy! -CB —————————————————————————– The Rocks around Glacier National Park, Montana: Introduction to the formations The geology around Glacier National Park is great for beginners because the area is … Read more
Here’s a new video from Greg Willis, the same guy who brought us a fine video on Piedmont geology. In this new opus (20 minutes), Greg details the geology of the Massanutten Synclinorium (Shenandoah Valley, Massanutten Mountain, and Fort Valley) in western Virginia. WordPress isn’t letting me embed it here, but you should go and … Read more
This weekend, I wanted to share some of the best work from this year’s Rockies field course students. Let’s start with a nice video by Marcelo Arispe: I thought this was a really nice job making a video using still images and a voiceover. The only thing I would change would be in the Gallatin … Read more
After my thesis defense at the University of Maryland, my mentor and friend E-an Zen asked me if I had ever heard of the Purgatory Conglomerate. I had not. Over the years, E-an has been a great source of new ideas and information to me, and so when he raises a notion, I pay attention. … Read more
Photo by Lily Edmon.
Beautiful fiancée for scale.
Let this be a lesson to you, kids. Don’t get too close to wild stromatolites, even if they are Mesoproterozoic… These exceptionally large stromatolites are on the threshold of the Grinnell Glacier, in Glacier National Park, Montana. No stromatolites or geologists were harmed during the production of this blog post. Photos by NOVA Rockies student … Read more
Check out this selection of fine soups, as displayed at the front of a restaurant (that we bypassed) in Pamukkale, Turkey: Close-ups that may be easier to read: Bon Appétit!
“Pocket folds,” as my Rockies co-instructor Pete Berquist has defined them, are rock samples exhibiting folds that are small enough to stick in your pocket (and take back to your lab). Here’s a pocket fold that I found last week in the White Mountains of New Hampshire: I brought it home, and today I unpacked … Read more
Hello everyone, I’m back in my office after 7 weeks away. I had some great travels this summer, to Turkey, Montana, and New England… and great geological photos to share from each of those locations. I’m going to start off with something non-geological, though: something furry and alive! That, my friends, is a pine marten, … Read more
This is the coolest thing I’ve seen this week: a graded bed metamorphosed via Acadian mountain building: The graded bed starts at the Swiss army knife at left, where you see an abrupt transition between coarse grained metamorphic porphyroblasts (“pseudo-andalusites”) and finer grained quartzite. This was once a mud to sand transition when these were … Read more
… And here are some ripple marks from a block of the same sandstone in the previous image. Nice! Hope everyone is doing well. Lots of good geological experiences to report on, buy it’s hard to write a substantive blog post from phone… You’ll have to wait until I’m back at a computer!
Here’s a package of mudcracks from a block of riprap on the waterfront of Burlington, Vermont: Oh yeah….
Yesterday’s field work took us to this classic mass wasting site:
It’s late afternoon in Jackson Hole, with the sun dipping down behind the Tetons. I’m waiting for some students to finish up their hike in Cascade Canyon and ferry back across Jenny Lake. Here’s a snapshot of the moment:
Dashboard decor…
The students had placed this flag on te van antenna when I came out this morning… The other side says “it’s too gneiss!”
Here’s a nice sample of folded gneissic banding in basement complex of the Gallatin Range, Montana. According to Dave Mogk of Montana State University (who I met in person for the first time on Saturday), these high grade metamorphic rocks are as old as 3.2 Ga (billion years old). They experienced temperatures as high as … Read more
Greetings from Bozeman, Montana, where my students and I are on Day 3 of our Rocky Mountain Regional Geology class. Here’s a nice long example of plumose structure to start your Monday. More to come, now that I am back in the States and reconnected with my iPhone.