Straight-limbed open synform in an organic-rich formation of limited areal extent, featuring some brittle extensional features at the hinge. Kootenay National Park, British Columbia, summer 2011. (The bridge was broken before we got there.)
Following up on Friday’s fold, I wanted to share a few other images from our hike last week in Cascade Canyon of Grand Teton National Park. Lots of cool exposures of Archean basement rock there. Folds in gneissic banding: Big, angular mafic blocks in a felsic soup: Swarm of granite dikes on a mountainside: Asymmetric … Read more
The other day, driving south through Yellowstone on our way to the Tetons, I stopped to give my students the obligatory look over Yellowstone Lake’s West Thumb, looking east towards the snowcapped Absaroka Range in the distance. But in addition to a lovely view and a few birds, we found something really cool… Those are … Read more
Spied this lovely cricket while hiking the White Oak Canyon Trail in Shenandoah National Park yesterday: I realize there’s been a pretty high bugs : rocks ratio on Mountain Beltway of late; I’m just in summer mode, I reckon. And Virginia’s arthropod profligacy keeps bringing me into contact with these extraordinary segmented denizens of the … Read more
Yesterday afternoon, I spent some time in the field with a colleague, a student, and a gigapan. I took four gigapan images, which are of varying quality due to the partly cloudy day, but still you ought to find them interesting to explore. You can see any of them full-screen by clicking on the word … Read more
Lily and I took a hike yesterday over Old Rag Mountain, a popular destination in Shenandoah National Park. I took the opportunity to shoot a few gigapan images of the scene. If you click on the word “Gigapan” in the lower right of any of these images, it will take you to gigapan.org’s full page … Read more
Friday’s prompt to post the French Thrust shot gave me the opportunity to dig into my “Rockies” folder a bit. Here’s two other shots from my inaugural summer leading my Geology 295 field class out there. Hiking the trail to Grinnell Glacier: …It looks like we’re in the Appekunny Formation here, third from the bottom … Read more
Lamprophyre dikes on the Billy Goat Trail (Potomac, Maryland): are they offset because of a fault? Or not? Inquiring minds want to know!
I didn’t mention it yesterday, but there was one other structure that I saw at my newest outcrop on New 55. This is it: That’s a bunch of fractures. The broken rock is being altered by preferential fluid flow through the fractures. The fluid is not inert; it’s chemically active, and reacting with the rock. … Read more
As mentioned, I spent a significant part of last weekend was spent on a paleomagnetic sampling project with collaborators from the University of Michigan. On Friday, this was our field area: That’s the south slopes of Old Rag Mountain, a popular Blue Ridge hiking destination because unlike many Virginia peaks, when you get to the … Read more
The past couple of days, I’ve been in the field, collecting samples with Dr. Fatim Hankard, a post-doctoral researcher from the University of Michigan, and Matt Domeier, a PhD candidate from that same fine school. We’re interested in using Virginia’s wealth of Catoctin formation feeder dikes to do paleomagnetism measurements that might help us constrain … Read more
The other day, Chris Rowan of Highly Allochthonous posted some pictures (and video!) of the Teton Range in Wyoming, a normal fault-bounded block of rock that has rotated along a north-south axis, with the west side dropping down and the east side rising up relative to the floor of Jackson Hole. This is classic “Basin … 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
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
Lockwood started it. He grabs two new lists from National Geographic “Our Amazing Planet“: the Ten Most Visited National Parks and the Ten Least Visited National Parks. Says he: Bold the ones you have visited, and italicize the ones you’ve never heard of before. Most visited: 10: Glacier 9: Acadia 8: Grand Teton 7: Cuyahoga … Read more
I mentioned going out in the field last Thursday with Liz Johnson‘s “Geology of Skyline Drive” lab course at James Madison University. We started the trip south of Elkton, Virginia, at an exposure where Liz had the students collect hand samples and sketch their key features. Here’s one that I picked up: Regular readers will … Read more
In the 1987 comedy Planes, Trains, and Automobiles, John Candy and Steve Martin have a funny experience. It involves a cozy hotel room (one bed only) and the two travelers are huddled up for warmth. As he wakes up, John Candy thinks he is warming his hand “between two pillows.” At hearing this, Steve Martin’s … Read more
On my structure field trip just over a week ago, we found the contact between the Mesoproterozoic-aged Blue Ridge basement complex and the overlying Neoproterozoic Catoctin flood basalts (now metamorphosed to greenstone). This nonconformity can be found just west of the Appalachian Trail at the Little Stony Man parking area in Shenandoah National Park. Here’s … Read more
It is time to debrief the post-NE/SE-GSA field trip that I went on, affectionately dubbed the “Transect Trip” for the past 27 iPhone-uploaded “live”-geoblogged posts. First off, I’d have to say that I enjoyed the live-field-blogging experiment overall, though I’ve got some critiques of the process and products. I think it’s amazing that I can … Read more
A new paper in the journal Geology examines an interesting question: how can you tell feeder dikes from non-feeder dikes? The answer is, normally you can’t. Normally, there’s no way to tell for sure whether a given dike actually funneled magma to the paleo-surface, or whether it never reached the paleo-surface. The reason for this … Read more