Friday Fold

Friday fold: Yin-Yang at Swift Dam

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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

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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: [gigapan id=”176119″] link Here’s one with … Read more

Friday folds: Fox’s and Foch’s

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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

Friday fold: Lawson Syncline and Mount Inflexible

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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

Friday fold: Opal Range, Alberta

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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

Friday fold: subglacial drag fold (Pleistocene) in Cretaceous sediments, Alberta

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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

Friday fold: Flow banding in obsidian, Newberry Volcano National Monument, Oregon

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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!