Friday fold: Buckle vs. passive folding in the Chancellor Group slates
The Friday fold is an outcrop in Yoho National Park that showcases differences between buckle folding and passive folding.
Friday Fold
Friday fold: Contorted Rome Formation next to the Max Meadows Fault
My student Mercer Parker shot this one over to me the other day: Click to enlarge Those are the slim strata of the Rome Formation (a.k.a. Shady*), strongly deformed in the region adjacent to the Max Meadows (“M&M”?) Fault. Thanks, Mercer! _____________________________________________ * Will the real slim Shady please stand up?
Friday fold: Warspite Anticline
A final guest Friday fold from reader Howard Allen, who I’m pleased to be meeting up with in Banff late next week… Howard writes the following in describing this lovely scene: Warspite Anticline, Peter Lougheed Provincial Park, Alberta. Photo is a telephoto shot (hence the strong blue alpine haze–the colour cast is an accurate rendition … Read more
Friday folds: Acadian metamorphics and pegmatite from coastal Maine
Some folds this week from coastal exposures in western Boothbay Harbor, Maine, where I’m on vacation for one more day… Acadian metamorphics (schist, gneiss), with injected granite pegmatite that has also been folded (and boudinaged): Happy Friday!
Friday fold: the Castile Formation at the State line outcrop
The Friday fold visits the Permian basin of west Texas. There, the Castile Formation exhibits gorgeous inter- and intra-bed folding.
Friday fold: tortured turbidites at Devil’s Slide
Marek Cichanski (of De Anza College near the south end of San Francisco Bay) contributed this week’s Friday fold: Marek says: The locality is a place near San Francisco called Devils Slide. It is a piece of the coastal highway built along a steep mountainside above the ocean. This unstable stretch of road was recently … Read more
Friday fold: differential weathering of carbonate intraclasts in mudstone
Howard Allen is the documentarian of this week’s fold: Howard writes that this is: Middle Cambrian Chancellor Formation rock with recessive weathering intraclasts(?). Hamilton Lake trail, Yoho National Park, British Columbia. My interpretation of this one is a little shaky–it was raining when I took the photo (in 1982) and I was hiking with a … Read more
Friday fold: subthrust syncline in lower Helderberg limestones, Corridor H
Click to enlarge You owe it to yourself to click through and make this bigger. Check out the prominent lower left to upper right thrust fault, and the shattering in the shorter limb of the underlying syncline. Is that another one to the right? Happy exploring, and happy Friday!
Friday fold: Lyautey Syncline
Another guest Friday fold from Howard Allen: View looking north at Mount Lyautey, on axis of the Lyautey Syncline, from Aster Lake trail, Peter Lougheed Provincial Park, Alberta. Rocks are carbonates of the upper Mount Head Formation, Carboniferous (Mississippian). Photo taken in 1981.
Friday fold: knuckling under in the Mesilla Valley shale
Here’s a fold I saw in Texas, in the Mesilla Valley shale, close to the contact with the Muleros Andesite at Cristo Rey: This is a pretty wild looking fold. Let’s zoom in on the most deformed portion: Annotation: white is top of the distinctive, blocky, buckled bed, and black is its bottom side. Red … Read more