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17 May 2013
Friday fold: Rorschach blot
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.
10 May 2013
Friday fold: New Market / Lincolnshire formation contact, Staunton, Virginia
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 full of fossil invertebrates. Explore it for yourself in this M.A.G.I.C. GigaPan: link A closer …
3 May 2013
Friday fold: Baxter and the boulders
Last weekend, after we checked Lily in for her race, I spotted some boulders near the check-in site. The next morning, once the race had started but before we could cheer her on, my field assistant and I went back to the boulders to check them out. My field assistant’s planners had forgotten to pack him a hat – so we improvised with a pair of fleece pants inverted on …
26 April 2013
Friday folds: Simple shear and the unfolding of folds
The Friday fold combines a moment of insight on a field trip in the Archean Superior Province and a new paper published this month in the journal GEOLOGY.
19 April 2013
Friday fold: Another from the depths of Mosaic Canyon
More folds from the charismatic Noonday Dolostone in Mosaic Canyon, Death Valley National Park, California: Annotated: Happy Friday!
12 April 2013
Friday fold: Mosaic Canyon
For the Friday fold today, let’s return to the warmth of Mosaic Canyon in Death Valley National Park, California: Can you see it there? Let’s zoom in on the dark area in the middle of that first photograph…. Ahh! Now that’s a fold to end the week on! Enjoy the weekend, everyone.
5 April 2013
Friday fold: shale and sandstone from West Texas
No time for more details than that – sorry! Happy Friday and a restful weekend to all!
29 March 2013
Friday fold: “V”
The Friday fold photo was taken this morning on a GigaPanning expedition, and shows a small syncline within turbidite strata of the Martinsburg Formation, Page Valley, Virginia.
22 March 2013
Friday fold: the case of the strangely stout stylolites
Today, we return to my field trip from last week, for a look at an odd outcrop of the Ordovician-aged Edinburg Formation: Note the car key with green lanyard, to provide a sense of scale. It’s folded, as the yellow bedding traces show in this annotated version: But what really caught my eye about this outcrop were the odd stylolites (pressure solution “seams” with a wiggly morphology and a concentration …
15 March 2013
Friday fold: a recumbent anticline in an abandoned quarry
Yesterday, I spent a pleasant day in the field with John Singleton, the new structural geology professor at George Mason University. I was showing John a couple of sites I’ve used as field trip locations for the GMU structural geology class, and John was showing a couple of new sites to me – places he visited on last fall’s Virginia Geological Field Conference. I missed VGFC last fall, as I …
Callan Bentley is an assistant professor of geology at Northern Virginia Community College in Annandale, Virginia. He is particularly interested in structural geology and the evolution of the Appalachian mountain belt. Callan draws cartoons and writes for EARTH magazine. He lives in the Fort Valley of Virginia.
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