Callan Bentley I’m playing around with Microsoft Expression screen capture for the book project I’m working on, and here is a video I worked up yesterday as a demonstration of this new way of telling a geologic story: The Grenville Orogeny and the rifting of Rodinia (opening of the Iapetus Ocean): [youtube=”www.youtube.com/watch?v=g6itZWD8bQc”] I’m frustrated by the way … Read more
The final meeting of my spring semester Snowball Earth class was a field trip to the University of Maryland, hosted by Snowball guru Jay Kaufman, a specialist in chemostratigraphy using stable isotopes. Here, Jay welcomes the class to his wet lab: Doing chemostratigraphy takes lots of samples. Here’s a drawer full of samples from one … Read more
I’m cleaning out my backlog of old photos. Here’s some small living things that I’ve taken pictures of in the relatively recent past… Let’s start with two butterflies in the Gallatin Range, Montana: Returning to Virginia, here’s a fuzzy little white moth: A crane fly is next… (M.A.G.I.C. has been churning out lots of crane … Read more
The Friday fold “guest fold” series continues with a folded ultramylonite from South Africa.
This is Dyer Island, off Gansbaai, southern South Africa, a little west of Cape Agulhas: Those are seals, a huge, crazy crowded colony of Cape fur seals. They are loud. They create a God-awful stink with all their fishy excrement. It was like being in a BBC nature program to see this firsthand. I could … Read more
A few shots from Fossil Falls, in the southern Owens Valley, California… This is the now-dry river bed of the Owens River. There’s abundant evidence of water-induced erosion (potholes, polishing, etc.), but nary a drop of water to be seen – Though this particular portion of the Owens River drainage dried up in the Pleistocene, … Read more
Team M.A.G.I.C. had a productive month. Here are some of our latest images: link link link link link link link
Here’s the view riding up (or down) Sulphur Mountain, Banff, on the gondola: As you can probably tell from the cable lines’ misalignment, this was a composite (stitched) photo. Mt. Rundle is in the background. If you turn to the left, you can see Tunnel Mountain, south of the town of Banff: Tunnel Mountain is … Read more
Another guest submission for the Friday fold: Callan – Please find enclosed a collection of photos you could possibly use for a future Friday Fold blog post. The following photos were all taken by me on Sunday, April 29th, in the vicinity of Bedford Peak and the Maple Springs Trailhead (Silverado Canyon Road), Cleveland National … Read more
Yesterday, I introduced percussion marks to this blog space. Here are some other shots of this distinctive “shatter” structure, but in a vein of hydrothermal (milky) quartz exposed on Bear Island, between the C&O Canal and the Potomac River (about right here, just west of the trail): Sometimes percussion marks are accompanied by radial fracture … Read more
One of the ~350 or so blogs I subscribe to is Arctic Sea Ice by Neven. Today, he put up a post highlighting new daily data from IARC-JAXA, a collaboration between the International Arctic Research Center (IARC) at the University of Alaska-Fairbanks and the Japan Aerospace Exploration Agency (JAXA). Check it out. Here’s a couple … Read more
Further upstream from the Skolithos and the snake and the diabase rip-rap… The field review team wandered down onto a creekside outcrop of Antietam Formation. The Antietam is a quartz sandstone, with variable levels of deformation, depending on where you look. In some places, it has been gently strained with the little Skolithos tubes taking … Read more
Seen in rip-rap on the side of Naked Creek, a week ago yesterday: This boulder is exotic to its current location. It is typical of medium- and coarser-grained diabase from the Culpeper Basin, a Triassic rift valley east of the Blue Ridge. The main minerals are plagioclase (light-colored) and pyroxene (dark colored).
Callan and his wife hike Cory Pass in Banff National Park, Canada, and encounter some geology, some solitude, and a spectacular landscape.
The word “Shenandoah” is thought to mean “daughter of the stars,” a lovely turn of phrase even if there’s no evidence for it. The name has been applied to a variety of features in the Commonwealth of Virginia. One is the Shenandoah River, and the valley in which it flows. Here’s a look at the … Read more
Handwritten notes by Ernst Cloos (legendary structural geologist from Johns Hopkins University) on the area I visited last Monday on a field review of the new geologic map of the Elkton East quadrangle by Chelsea Jenkins, Chuck Bailey, Mary Cox and Grace Dawson.
Max Arndt contributed this week’s Friday fold: (click on the image to get to a larger sized version on Max’s Flickr page) That’s the Warah Formation exposed on the Batain Coast of northeastern Oman. This is the thrust front of a thin-skinned fold and thrust belt. I think it’s just lovely! Max has a ton … Read more
As I mentioned, Monday had me out in the field, looking at the western Blue Ridge and eastern Valley & Ridge provinces in Virginia. This was a field review for the new geologic map of the Elkton East quadrangle by Chelsea Jenkins, Chuck Bailey, Mary Cox, and Grace Dawson. Immediately after lunch, we visited an … Read more
Saw this fellow on Monday, coiled up next to an outcrop of Antietam Formation in Naked Creek, northwest of Elkton: It had flattened its head to make it very spade-shaped. The right eye was cloudy – perhaps snake glaucoma? Or maybe it was just getting ready to shed its skin?
On Monday, I was out in the field at the Blue Ridge / Valley & Ridge transition (“boundary”?) in the Elkton East quadrangle, where Chuck Bailey and students (from the College of William & Mary) were leading a field review of their new geologic map. A field review is a form of field-based peer review, … Read more