Callan Bentley Two summers ago, my wife (then my very new wife) Lily and I participated in a two-week workshop for teachers on the energy resources of Wyoming. We also indulged in a visit to a mineral resource site: South Pass City, a site in the southern Wind River Uplift that was the second oldest incorporated town … Read more
Hey, that quartzite boulder has measles! Or is it bubonic plague? Or maybe it’s just acne? Look closer and see if you can deduce what these things are: These conical fractures are percussion marks. They form when a cobble smacks into another cobble underwater, propelled forward by a powerful current. As the two rocks knock … Read more
Archaeology meets geology in this visit to the Piney Branch valley of Rock Creek Park in Washington, D.C. Cretaceous deposits of cobbles of Cambrian quartzite were quarried by Native Americans and modified into tools thanks to the fact that they break with a conchoidal fracture.
Brood II. We gots ’em. The noise is so cool….
Saw this educational graffiti on the campus of Carleton College a few weeks ago: Seems like a great way to get students to grasp the relative spans of geologic time.
Renowned geological aerial photographer Michael Collier gives Callan a lift over the Fort Valley and Massanutten Mountain in his two-seater Cessna.
It’s been a busy week. Hardly any free time. Here are a few pictures from my yard, taken this morning. Please accept them in lieu of a real blog post: Eastern cottontail: Mountain laurel: The cicadas are trilling in a mad, constant, siren-like noise. It’s intense, and otherworldly. Talk to you later…
Found this fellow while weed-whacking thistles last week… A lovely iridescent purple – the photos don’t really capture it.
I was up in Carleton College (Northfield, Minnesota) for most of the week, working on a new teaching module for the InTeGrate project. On the way between our work area and the cafeteria where we ate lunch, we passed the geology department’s rock garden. They have some great specimens there, some big, some small. Here … Read more
Last week, I got a great new book from Amazon. I had pre-ordered it months ago, so when it finally arrived, I was delighted, and dove right in. Within 24 hours, I had finished it. It’s the story of how my friend Forrest Pritchard re-made his family’s farm into a sustainable enterprise by going organic. … Read more
I’m dismayed at the news yesterday out of Oklahoma – the violent storm that ended lives. This morning on Facebook, I noticed that many of my pious friends were letting the rest of us know that they were praying for Oklahoma, or more specifically, for the victims of the storm. At the same time, the … Read more
Spring is back in the Fort Valley, and that means many serendipitous bug encounters. I think it’s safe to say that the Monday Macrobug is back as a regular feature on Mountain Beltway for the foreseeable future! Today, I give you…. a weevil! You’re welcome.
The broad symmetry (with smaller-scale variations) of this fold caught my eye as particularly artful when I saw it (at Howard’s recommendation) last summer in the Canadian Rockies: Kootenay National Park, British Columbia, Canada. I see a butterfly. What do you see? Happy Friday.
Kilbourne Hole is the crater of a maar volcano in southern New Mexico, just across the state line from El Paso, Texas. I went there the weekend before last with a team from El Paso Community College, led by Joshua Villalobos. This is the place where xenobombs come from! If you go to the right … Read more
The week before last, on the flight home from Texas, I finished reading Dark Star Safari, Paul Theroux’s 2004 account of traveling overland through Africa from Cairo to Cape Town. I’ve enjoyed Theroux’s traveling writing very much over the years, and although he’s written some great novels (I’m thinking of Mosquito Coast), most of them … Read more
Found this small, flat brachiopod fossil last fall just down the road from my place in the Fort Valley. Lovely little thing… That’s all I’ve got for you today!
Termites can fly. But not all termites. Around here, the only flying termites are the reproductives – the fertile males and females that a termites colony produces periodically. It seems to be associated with the advent of spring. I spotted this group a couple of weeks ago, when I noticed the sunlight catching in their … Read more
We had another flood on Passage Creek on Wednesday, and into Thursday morning. Here are a few photos and GigaPans for those of you who like flood imagery: link link link Making GigaPans of the scene: Some images of the flood itself: Aftermath: http://www.gigapan.com/gigapans/129490 http://www.gigapan.com/gigapans/129543 http://www.gigapan.com/gigapans/129569 10.3 feet was the maximum gauge height this time … Read more
Happy Friday! Here’s a view of the folded contact between the (older, lower) New Market Formation, and the (younger, upper) Lincolnshire Formation, as exposed in Staunton, Virginia: The contact has been folded, pretty intensely: The New Market Formation is massive, light-colored, and exhibits fenestral texture here. The Lincolnshire is darker, more thinly-bedded, and is chock … Read more
This is my final post on the pre-GSA-Minneapolis structural geology field trip to the Superior Province. The photo above shows a roadcut exposure of boudinage in xenolith-bearing Vermillion Granitic Complex. Here’s another, smaller, more brittle example of boudinage, from another site, the following morning: Gee, it only took me 1.5 years to blog that trip … Read more