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