I ran out of folds last December, I asked for help on Twitter. Laura Hamilton was among the first to respond, with a link to this image: @callanbentley Hartland Quay, Devon UK. Huuuuge chevron folds! pic.twitter.com/7bhRfLib9Y — lau.rah (@hammijam) December 23, 2013 Thanks, Laura, for another great image!
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!
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 … Read more
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!
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 … Read more
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 … Read more
Another guest submission for the Friday fold. This one comes to us from Christie Rowe, and it shows a tiny kink fold in the Bitter Ridge formation (playa limestones):
My former student Aaron Barth sent me a few photos of disharmonic folding in metamorphic rocks in Ireland for a guest Friday fold…. Awesome! Thanks Aaron!
I ran out of folds last week, so earlier this week, I asked for help on Twitter. Laura Hamilton responded with a link to this image: @callanbentley El Gordo, S Spain. Huge turbidite block! Folded over as it moved over the seafloor 🙂 pic.twitter.com/L4INxmtLTq — lau.rah (@hammijam) December 23, 2013 Sweet. And you can’t complain … Read more
The laccolith of Cristo Rey, at the Chihuahua / Texas / New Mexico triple point, is host to some cool geology. It’s cored by the Campus Andesite (47 Ma, Eocene) but surrounding the intrusion are a slew of sedimentary rocks, include the Turitella-bearing limestones of the Buda Formation and the shales and sandstones of the … Read more
Hiking up to Crypt Lake in Waterton Lakes National Park, Alberta, Canada, you can see some sweet stromatolites, and folds, too. But it’s not only that – you can also find some decent kink bands in those strata, too! These kink bands will serve as our Friday fold, on this Crypt-Lake-o-centric week. Here’s a second, … Read more
Hiking up to Crypt Lake in Waterton Lakes National Park, Alberta, Canada, you can see some sweet stromatolites, We’ve already taken a look at the falls, but today, let’s zoom into the folds exposed in that shadowy cliff near the center… These limestone layers are Mesoproterozoic in age – they’re part of the Purcell (Belt) … Read more
The Friday fold can be found this week at Turtle Mountain, Alberta, where it triggered a massive landslide.
Here’s a sample that my Physical Geology students see on their field trip to the Billy Goat Trail:
A guest post today for the Friday fold from my former student Naseem Naghdi, who’s now in southern California: The Ventura Avenue anticline is a fault-propogated fold and is located in the core of (Conoco’s) San Miguelito oil field, which is on the Ventura-Rincon anticlinorium. Carbon dating of seashells have indicated that the terraces range … Read more
The Friday fold is a cast-off specimen from the USGS. A lovely little orphan, its marble and micaceous layers have polished up nicely. Two sides of the sample are presented here.
The Friday fold is a trio of hand samples of folded banded iron formation from South Africa. Collected in 2012 as float from the “contorted bed” outcrop in downtown Johannesburg, these samples are only now being cut and polished in the lab at NOVA.
Here’s a scene from last summer’s Regional Field Geology of the Northern Rockies course… students examining and sketching some tight folds in Cretaceous strata of the Western Interior Seaway, crumpled beneath the Dorado Thrust (a more southerly equivalent of the infamous Lewis Thrust to the north)… I’ve featured this site before, in a previous Friday … Read more
Red argillite (Grinnell Formation?) and white quartzite strata from Glacier National Park, Montana. Heavily adorned with lichens… With bedding traced out… Happy Friday to you!
Here’s a photo from Tom Biggs (University of Virginia), taken on the NOVA Rockies field course last summer. It shows a recumbent fold along the Front Range of Glacier National Park, in Montana, just north of Two Medicine Lake. I hope you get some ‘recumbent’ time this weekend… I know I could use some rest. … Read more