A final Friday fold (for now) from Howard Allen: This is : A view south across Kananaskis Lakes, Peter Lougheed Provincial Park, Alberta, through mist/low-hanging clouds. Snow highlights the Sarrail Creek Syncline and Warspite Anticline on the north faces of mounts Fox (left/east) and Foch (right/west). Rocks are Lower Carboniferous carbonates of the Banff, Livingstone … Read more
View of Lawson Syncline looking obliquely along strike (SSE) from an unnamed peak SW of Mount Inflexible, Kananaskis Range, Alberta. The axis of the syncline forms the bottom of the valley and plunges slightly toward the south. The syncline is in the hanging wall of the Sulphur Mountain Thrust sheet. On the right side of … Read more
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!
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.
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!
I’m very nearly delinquent on posting the Friday fold… Here you go – a Google Earth view of a differentially-weathered fold partly above and partly below sea level in Chilean Patagonia, south of Puerto Natales: They call it Isla Escarpada. Awesome. Here’s a Google Maps link if you want to explore it yourself. Happy Friday!
Spring is almost here! As you get ready for the equinox, enjoy this gentle fold on a Friday: These are turbidites (graywacke and shale) of the late Ordovician Martinsburg Formation, seen in Edinburg Gap, western Massanutten Range, greater Shenandoah Valley, Virginia. Bedding is flexed very slightly here, from moderately-dipping to more steep, and then back … Read more
Reader Mike Pendergrass contributes this Friday’s fold: I found your blog a couple years ago and I share your love of structural geology. I did my Master’s Thesis while at Northern Arizona University in the early 80’s and mapped an area on the Mazatzal Mountains of central Arizona. The Mazatzals in my field area contain … Read more
Back at the beginning of January, I asked for help on Twitter for Friday fold fodder. Here are three responses I got: @callanbentley one of my favorites from South Georgia Island. Have more on the laptop. pic.twitter.com/UaRtxM77Vm — John Van Hoesen (@Taconic_Musings) January 8, 2015 @callanbentley 2 folds from my SC Inner Piedmont MS thesis … Read more
Another one from Kim: Kim says: Pygmatic folds in the Precambrian Irving Formation. I think this is 1.7 Ga deformation, late in the Yavapai orogeny, which added various arcs in Colorado to North America. Good place to think about strain ellipses in progressive deformation. Zooming in on the best part, and dialing up the contrast … Read more
Kim Hannula shares a fold today: Kim says: The rocks folded here mostly the Devonian Ouray Limestone. There’s a fault through the outcrop, and another fault to the left of the photo. Regionally, the faults are mapped as normal faults, mostly with the east (right in photo) side down. Locally, that’s not what I see … Read more
Elizabeth Kosters contributed this week’s Friday fold: It’s from Rainy Cove, Nova Scotia, Canada. Click through to read Elizabeth’s post on the site. Happy Friday!
Zoltán Sylvester has contributed today’s Friday fold, an anticline in the Ross Sandstone of Ireland: Click image to go to the source (full sized). Thanks Zoltán! Happy Friday everyone.