Friday fold: Nice gneiss from Salt Lake, Utah

Another guest Friday fold… this one from my colleague Tiffany Rivera of Westminster College in Salt Lake City, Utah, the one who brought you yesterday’s thrombolite pictures… Tiffany writes that these shots come from a man-made boulder field / berm along the lake. The boulders were these beautifully folded gneisses. Antelope Island exposes some of … Read more

Friday fold: recumbent limestones of coastal Grosseto

Samuele Jæger Papeschi not only provided this week’s Friday fold, but he also serves as its sense of scale: According to Samuele, these are: folded metalimestones in Punta delle Rocchette, Grosseto. This are pretty interesting transected folds, showing about 10 degrees of foliation dip in respect to their axis Thanks for sharing, Samuele, and happy … Read more

Friday fold: Himalayas, northern India

My colleague Martin Schmidt of the McDonogh School, who I know through the National Association of Geoscience Teachers eastern section, recently shared a bunch of fold photos with me. They have a “dated” feel because they were originally shot on slide film, but the folds themselves of course are timeless. I’ll be featuring a bunch … Read more

Friday fold: Apennine crenulation cleavage

My new social media buddy Samuele Jæger Papeschi and I collaborated on some goofy maps in August, but then he noticed my Friday folds, and like the very best human beings anywhere, Samuele offered to pitch in with a few folds of his own. (Other readers are encouraged to do the same!) Today, I’ll feature the first … Read more

New GigaPans from Team M.A.G.I.C.

Hampshire Formation outcrops on Corridor H, West Virginia: link (Marissa Dudek) link (Callan Bentley) Faults in the Tonoloway Formation, Corridor H, West Virginia: link (Marissa Dudek) Conococheague Formation, showing stromatolites and cross-bedding: link (Callan Bentley) link (Jeffrey Rollins) Tiny folds and faults, from a sample I collected somewhere, sometime… oh well, it’s cool regardless: link … Read more

Paleoslump features and fluvial incision in the Conemaugh Group, West Virginia

The answer to this week’s geological interpretation contest is revealed, sort of. Annotations, GigaPans, and outcrop detail photos reveal the story of equatorial fluvial incision and ancient slumping during the Carboniferous ice ages.

Friday fold: Yin-Yang at Swift Dam

What is Matt looking at here? Matt was one of my Rockies students this summer, a geology major at the University of Virginia. Together with another UVA student and students from Mary Washington University and George Mason University, Matt embarked on a mountain-climbing hike during our evening camping at Swift Dam, near Depuyer, Montana. The … Read more

Friday fold: a return to the duplex structure in the Gastropod Limestone

Some time ago, I featured as Friday fold the extraordinarily complex duplex structure to be seen in the Cretaceous “gastropod limestone” member of the Kootenai Formation at Sandy Hollow, Montana. Today, let’s take a deeper look through a couple of hand-shot GigaPan images: Here’s the bigger of the two: link Here’s one with students for … Read more