Yesterday, I took about fifteen members of the DC Science Writer’s Association on a walking tour of DC’s geology. I was honored to present the capital city’s epic geologic story to an esteemed crowd of professional science writers from Nature, Science, the National Academies, the National Institutes of Health, the Washington Post, and other institutions. … Read more
Today’s Friday fold takes me back 25 years, to when I visited the Outdoor Lab with my science class in Arlington County Public Schools. I revisited this exemplary outdoor education facility on Tuesday, at the invitation of its director, Neil Heinekamp. Neil wanted a geology “expert” to take a look at their rocks, and I … Read more
Here’s a joint extracted from gelatin during this year’s GMU structural geology “Make a Joint” exercise: A soda bottle full of congealed gelatin serves a “rock.” We then use construction clamps to impart a stress field to the gelatin bottle. Into it, we inject fluid plaster of Paris. The extra pore fluid pressure causes a … 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
Remember the LaHood Conglomerate? Here’s a few field photos of my Rockies class visiting it last July: Amphibolite clast: Marble clast: I love how well-rounded these clasts can be — like eggs. When these grains were loose cobbles, tumbling down into the Belt Sea, the Earth was only 3 to 3.5 billion years old. The … Read more
Just got this in an email: “Hi professor Bentley, This is [redacted], I had you for Geology last Spring. I just wanted to email you to first off, thank you, and second off, to ask some questions. Before I took your class Science was my worst subject , and I did everything to avoid taking … Read more
This series of cartoon images ended up on the board yesterday in Historical Geology lab… E = erosion D = deposition Yes, oversimplified: I didn’t include the newest thinking about the subtleties involved in putting together the Brahma and Vishnu Schists and Zoroaster Granite, and I didn’t include mention of faulting (either ancient or more … Read more
When I was done with my sophomore year at William & Mary, I embarked on a time-honored tradition among W&M geology majors: the Geology 310 Colorado Plateau field course. Jess alluded to this same course in her Magma Cum Laude contribution to this month’s Accretionary Wedge geology blog “carnival,” too. My version of Geology 310 … 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
I’ve developed a little cartoon diagram to show four stages of river landscape evolution. I use this image in Physical Geology when discussing how running water erodes the land. Check it out: There are two rows, and four columns. The columns are the four stages of river landscape evolution: youth, maturity, old age, and rejuvenation. … Read more
World! …I have an announcement! Three of my structural geology students from this past semester are now geoblogging… can’t say I had anything to do with that, but there it is. They are: Joe Maloney at Fossiliferous Weekly Aaron Barth at Got The Time and “AlanP” at Not Necessarily Geology Please check them out, and … Read more
A million years ago, I posted about my inaugural attempt to use the Butter Buster to illustrate shear zone deformation to my structural geology students. Today, using the UnFREEz program to make an animated GIF (Thanks, Lockwood!), I give you the Butter Buster animation:
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
On my structural geology field trip this past weekend, I made one major modification compared to last year’s iteration. I added a fifth detailed “field study area” at an outcrop of the Swift Run Formation, a Neoproterozoic sedimentary unit that is discontinuous in extent between the underlying Blue Ridge basement complex and overlying Catoctin Formation … Read more
It’s a rough life, working in the places I have to work… here are a few photos from yesterday’s field trip on the Billy Goat Trail with my NOVA Physical Geology students. Photos are courtesy Dr. Meg Coleman, who joined us for the hike. A post-lunch lecture on river incision (note the two prominent bedrock … Read more
Yesterday, I took my GMU structural geology class to the Billy Goat Trail, my favorite local spot for intriguing geology. Unlike last year, we managed our time well enough that we got to clamber around on the rocks downstream of the amphibolite contact. Here’s Sarah, Lara, Kristen, and Alan, negotiating a steep section: Justin, Joe, … Read more
Today, a few photos of my spring Environmental Geology class doing a New Orleans Case Study lab using our lovely Emriver river process simulator: That’s it. I mainly shot these photos for Steve Gough, as NOVA is participating in the new grant he submitted to NSF, but I figured I would share them here, too. … Read more
My cat loves to sit on, or lie on, paper. Maps are here favorite, but she will take a pile of structural geology labs instead, if that’s all that’s available.