You are browsing the archive for 2014 January.
31 January 2014
Todd Redding is our genorous sponsor for this week’s Friday fold. Todd reports that this boulder is derived from the Okanagan Metamorphic Complex near Penticton, British Columbia, Canada. He gives its lat/long as 49°28’14.10″N, 119°30’23.14″W. Did you spot the small fault in there, too? Thanks for sharing, Todd!
30 January 2014
One of the intriguing rocks you find in Virginia, at the interface between the Valley and Ridge province and the Blue Ridge province, is distinctive brecciated Antietam Formation. The Antietam (sometimes known as the “Erwin,” especially in Shenandoah National Park), is a quartz arenite (quartz sandstone) that has been variably fused to quartzite in some places (but not others). It’s been deformed, sometimes spectacularly so, as we see when the …
29 January 2014
It’s another cold morning in the Fort Valley. To celebrate winter’s continuing grip, please enjoy these images from last Friday morning, on my way to work… Frost on plants: Frost on barbed wire: Finally, here’s a time-lapse video (5 times actual speed) of the first 6 miles of my commute (walking, then driving):
24 January 2014
Reader Eric Fulmer contributed this week’s Friday fold. It’s a beauty! Eric writes that this outcrop is from “the Belgian Ardennes near Durbuy. There’s a well-exposed anticline along the Ourthe River. The stone is late-Devonian limestone typical of the immediate area that was later deformed regionally due to the Variscan orogeny. The Ardennes are classic fold-and-thrust belt, much like our Valley-and-Ridge province.” Very cool indeed. Thanks for sharing, Eric!
21 January 2014
I was first alerted to the proposal of a new bill in the Virginia House of Delegates last Wednesday by a colleague at James Madison University, Eric Pyle. Eric and I serve as state Councilors for the state of Virginia in the National Association of Geoscience Teachers. As such, we are sincerely concerned about any policy that would weaken science education in the Old Dominion, in particular when it comes …
18 January 2014
A photo of the iconic dune cross-beds at Zion National Park gets the Bentley Annotation treatment, and comes out looking like a stained glass window. Take a look at both photos and see if you can answer the question, “Which way was the wind blowing?”
17 January 2014
Another guest Friday fold – again, from the structural geologist Christie Rowe at McGill University in Montreal: Christie describes this as: growth faulting in beautiful fluvial sediments… Accordingly, I have squinted and annotated it a bit: Happy Friday!
16 January 2014
While at the University of Texas at Austin, where the Jackson School of Geosciences was hosting the Summit on the Future of Geoscience Education this past weekend, I was impressed to see a well-developed rock garden outside the student center. Here’s an example of a stretched-pebble conglomerate from that garden: Note the nice epidote boudins running down the middle. The way the foliation “flares” at the bottom suggests another boudin …
15 January 2014
While at the University of Texas at Austin, where the Jackson School of Geosciences was hosting the Summit on the Future of Geoscience Education this past weekend, I was impressed to see a well-developed rock garden outside the student center. Here are three boulder-sized samples of folds from that garden. Enjoy! Jackson School of Geosciences pen for scale, natch.
14 January 2014
While at the University of Texas at Austin, where the Jackson School of Geosciences was hosting the Summit on the Future of Geoscience Education this past weekend, I was very impressed with the backdrop behind the main desk at the student center. It showed lovely meso- and macro- scale folds, and exquisite boudinage. I never found out the source or story behind this rock, but it’s certainly lovely. I’m sure …