Callan Bentley Howard Allen is the Friday folder who keeps on giving… Here’s his latest: Multiple folds at top of ridge, Opal Range, Alberta. Photographed from Kananaskis Highway 40, looking SE. Beds are Carboniferous carbonates, probably Mount Head and/or Etherington formations. There are lots of great folds to be seen along that road. The Kananaskis Trail is … Read more
Another Friday, another Friday fold from Howard Allen: Folds in near-vertical beds, north side of Grizzly Creek, Opal Range, Alberta. Beds are Carboniferous carbonates, Mount Head and Etherington formations. Enjoy your day!
Howard Allen, a retired petroleum geologist from Calgary, and longtime reader of this blog, contributed this week’s Friday fold: Subglacial drag fold (Pleistocene) in Upper Cretaceous Horseshoe Canyon Fm. bedrock (sandstone, shale). The locality is SE of Drumheller, AB at UTM 12U 394247 5692469 (WGS84). Did you hear that right? Yes, you did: This is … Read more
Lockwood Dewitt is the purveyor of this week’s Friday fold ensemble: All these folds are primary (not tectonic) in nature: they are flow banding of the viscous lava that oozed out to make the Big Obsidian Flow at Newberry. And closer in: One more: Awesome stuff! Thanks for sharing, Lockwood! Happy Friday, everyone!
The Friday fold is some crumpled sedimentary rock near the Hayward Fault in California.
Kate Littler sent in this Friday fold, via Twitter: lovely parasitic folds in the Carb limestone, West Angle Bay south Wales. Awesome. Looks like a great place. Thanks, Kate! Happy Friday!
Two nice new examples of soft sediment deformation structures in Pennsylvanian-aged clastic sedimentary rocks from West Virginia.
While out at the eastern section of NAGT’s annual meeting last weekend in West Virginia, I participated in a field trip to look at the stratigraphy of the Bolt Mountain section of Pottsville Group strata. One thing that was particularly eye-catching about the sandstones we saw was that many of them had been stained by … Read more
Here’s a nice example of spheroidal weathering in a sandstone, developed using orthogonal jointing and bedding: This is one of many sites I visited Saturday near Bolt, West Virginia, on a field trip with NAGT’s Eastern Section.
Twitter follower Bob J. submitted this week’s Friday fold: Carboniferous cyclothems at Scremerston, Northumberland. Thanks Bob!
Last one in the triumverate sent in by reader Eric Fulmer: Annotated: Happy Friday and (for many of you) happy end of the semester!!
The Friday fold shows clastic detritus (turbidites or “flysch” from the Acadian Orogeny) crumpled into tight folds due to the later Alleghanian Orogeny.
Looking at Ordovician carbonates in Germany Valley, West Virginia, a few weeks ago on Rick Diecchio’s GMU sedimentology and stratigraphy course field trip: Lots and lots of brachiopods… Crinoid columnals mized with brachiopods: A set of coarsely-infilled trace fossils: Crinoid stem: Nice strophomenid brachiopod: Bryozoan? Receptaculid?
I was in Tucson this past weekend for a book project meeting, and my editor and coauthor and I took a hike on Sunday morning in the Tucson Mountains to Wasson Peak. Not far from the summit, we saw an epidotized tuff, where the fiamme and pumice blobs had undergone reactions to produce pods of … Read more
Milepost 127.4 (High, 2001) on the C&O Canal: …Cool if you’re into history. …Cool if you’re into economic geology. …Cool if you’re into Friday folds! Reader Eric Fulmer sent me this photo (along w/ two others you’ll see in weeks to come). Thanks, Eric!
Here’s another sight at the Eocene dikes site in Bluegrass Valley, Virginia, mentioned yesterday: That’s a gorgeous fault breccia, emplaced parallel to bedding, and parallel to the felsic dike (which can be found a few feet to the west / right of these photos): It was very poorly lithified, shockingly crumbly to the touch, considering … Read more
A virtual field trip to a quarry in far western Virginia, showing anomalous igneous intrusions (a dike and a sill) of Eocene age cross-cutting early Paleozoic carbonates.
This past weekend, I had a chance to visit Bath, Highland, and Alleghany Counties, Virginia, three amazingly beautiful places I had never before seen. I was tagging along on my colleague Rick Diecchio’s annual sedimentology & stratigraphy field trip for George Mason University. I was eager to learn from some awesome field sites from him … Read more
Two new GIGAmacro images of fossil scallops from Virginia’s Coastal Plain – Chesapecten nefrens: link Chesapecten jeffersonius: link My vision is to get the opposite side of each of these samples as well as a half-dozen other species in this genus, perhaps even multiple individual specimens of each species, to allow students to do a … Read more
Recently, I posted about an excellent road cut in Fort Valley showing well-developed 10 cm+ Zoophycos trace fossils. Presented here are three new GigaPan images (two outcrop; one macro) of Zoophycos from the Devonian-aged Mahantango Formation: link link link These images are part of a new “virtual field trip” that I organized to supplement my … Read more