One of my students wrote to me this morning with a question about the relationship between bedding, cleavage, and folding. He asked: I am not sure how we use the relationship between bedding and cleavage to interpret fold limbs. It seems if bedding is near vertical and cleavage is closer to horizontal, this would be … Read more
My friend Barry R., now residing in PostDocVille, Denmark, took a trip to Iceland last week to check out the eruption of Eyjafjallajökull. Unfortunately, by the time he got to the volcano, it was no longer spouting lava, but the scene is dramatic regardless. You can sample some of his photos below, or see the … Read more
The Lilster and I caught John McPhee give a reading tonight at our local uber-cool bookstore. Check it: First time I’ve seen McPhee live. Great stuff!
A friendly reminder that I’ve volunteered to host the next edition of The Accretionary Wedge, and I’ve chosen “heroes” as the theme. I invite all participants (geobloggers and geoblog readers alike) to contribute stories of their heroes. It’s time to pay tribute to the extraordinary individuals who helped make your life, your science, and your … Read more
Last Sunday, I took a solo hike along Pimmit Run in Virginia, accessing the valley via Fort Marcy, a Civil War fortification off of the George Washington Memorial Parkway. As always, I did a bit of geologizing along the route. One theme that emerged from the day’s photos was quartz veins. These veins form when … Read more
Today, our theme is vesicles. Here are some images of vesicles in basaltic lava flows in the Owens Valley of California, the same spot where we saw the baked fanglomerate that I showcased a few days back. In this photo (and the zoomed-in detail shot below), you can see a couple of things. One is … Read more
The first time I went to the Billy Goat Trail (Potomac, Maryland) with geology as the goal (as opposed to mere recreation), it was 2002. The trip was led by a professor at the University of Maryland. I was a graduate T.A. then, and didn’t know anything about the local geology. I remember at the … 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
Almost a year ago, on my old blog, I brought up the issue of the Suess effect. Go read that post if you don’t remember what the Suess effect is. If you want an executive summary, digest this: The burning of low-14C fossil fuels (because the fuels are old and the 14C has all decayed), … Read more
Searching through my photo archives this morning for something suitably “Eastery”… something in pastel colors, perhaps? … a petrified lagomorph? … how about an egg, or something egg-shaped? This is as close as I got: This is in the Owens Valley of eastern California, showing a boulder of the Mesozoic Sierra Nevada Batholith bearing a … Read more