Friday fold: the Ross Sandstone
The Friday fold is an exposure of the Ross Sandstone in Ireland, bent into a syncline that dives below water.
Friday Fold
Friday fold: the folded xenoliths of Duck Creek
On Duck Creek (Ellendale, NC quadrangle), you can see folded xenoliths within the Toluca Granite (383 Ma, 378 Ma, or 368 Ma, depending on which mineral you ask). The granite there contains xenoliths that contain pre-exisiting fabrics and structures, and we stopped at Duck Creek on the pre-GSA-Charlotte field trip I took to the Neoacadian … Read more
Friday fold: Pakistani Perplexity
In last week’s Friday fold, I featured this image… …which prompted commenter Lynn David to ask, What’s going on to the west side of that red/green rock cored syncline in #2? It looks like some sort of disconformity but then I looked closer (and man, does that rock redden up) and it appears that the … Read more
Friday folds: Google Earth screenshots
Found these lovely places over the past few weeks while searching (unsuccessfully) for Where On (Google) Earth? scenes… Click on any of them to make them bigger.
Friday fold: Chert chunk
Picked this one up the summer before last and took its portrait without recording too much else about it. There’s a small fault in there towards the bottom too. Sorry I forgot to mention it. My fault… Happy Friday! A light rock for “black Friday,” eh? Hope you had a happy Thanksgiving.
Friday fold: Neoacadian Inner Piedmont trip, part IV: Migmatitic metagraywacke
The Friday fold comes from a stop on the “Neoacadian Inner Piedmont” field trip that Callan attended prior to the GSA meeting in Charlotte, North Carolina, last week.
Friday fold: Boomer Falls
The Friday fold is seen at one of the stops on Callan’s pre-GSA-Charlotte field trip: a small waterfall in North Carolina’s Inner Piedmont.
Friday fold: dinner plate
The Friday fold appears on a flat slab along Maryland’s Billy Goat Trail.
Friday fold: South African gneiss
Another Friday, another fold. …By another Bentley!
Friday fold: Pofadder shear zone mylonites in 3D
Christie Rowe sent me these two images. They were taken by Ben Melosh and Louis Smit. The folded layers are mylonites of the Pofadder Shear Zone in South Africa. I love it when folds are expressed not only in profile, but also in three dimensions. Nothing in life could possibly be better. We’ve featured the … Read more
Friday fold: a dome in plane view
The Friday fold is a structural dome in Wyoming, as seen out an airplane window.
Friday fold: boxy syncline in West Virginia
Alan Pitts‘ Jeep Liberty for scale.
Friday folds: one from the Icefields Parkway
Limestone strata in a variety of orientations, with a nice tilted axial plane. Outcrop is on the east side of the Icefields Parkway, across from one of the many glacier overlooks. Lucy and Alex both wanted to act as sense of scale for this one… Can’t say I blame them.
Friday fold: Siim Sepp’s SS
Geoblogger Siim Sepp contributed this lovely fold. He says: I saw a nice fold in Ireland. I like it because it looks like SS to me which are my initials. If you want, you can post it as your friday fold. I haven’t used it yet in my blog. This small outcrop is in Donegal, … Read more
Friday folds: Selkirk Fan
The Friday fold is a selection of five fold photos from the Selkirk Fan in the Omineca Belt of British Columbia, submitted by structural geologist Marek Chichanski of De Anza College (California).
Friday fold: Natural Bridge area, Yoho National Park
The Friday fold, delayed by a week from last week’s contest, appears in Yoho National Park, British Columbia, near the “Natural Bridge” over the Kicking Horse River.
Friday fold: soft sed def in Kodiak
The Friday fold is a seaside outcrop of soft sediment deformation (not post-lithification tectonic deformation) on Kodiak Island, Alaska.
Friday fold: Kinked limestone laminae, Consolation Lakes
The Friday fold is a kink fold in thinly-laminated limestone from the same site as yesterday’s mysterious orange oncoids.
Friday fold: lower Martinsburg Formation near Bixler’s Ferry
The Friday fold is presented in photo, annotated photo, and GigaPan formats. It’s a cleaved anticline in lower Martinsburg Formation limy slate from Page County, Virginia. See if you can spot Mr. E. coli in the GigaPan!
Friday fold: Spray Mountain Group siltstone
Today, we return to Banff National Park, to the outcrops next to the parking area for Bow River Falls… Zoomed-in closer to the thinner layers at left: These strata (shale and siltstone) were laid down in the quiet aftermath of the Permo-Triassic extinction, as terranes colliding with the edge of North America (far to the … Read more