Lmst

2025-11-21

nearly vertical wall of gneissic rock with shadows, leaves, pine straw and shadows on it. a blue mechanical pencil is at the bottom for sale. the rocks is folded like a closed fan.

Anticline in the Paleoproterozoic Thomson Formation, near Jay Cooke State Park, Northeast #Minnesota. Deformation due to the Penokean Orogeny, ca 1850–1900 Ma. This is a favorite fieldtrip stop; included in the GSA Centennial Guidebook. An October picture from the archives. #geology #FridayFold 🧪⚒️

Outcrop along a riverbank showing a gray fine grained rock. Bedding planes dip in opposite directions on either side. Part of a bridge can be seen crossing the river.

Satellite image with the location of the outcrop shown. The St. Louis River has continuous exposure of the Thomson Fm towards the ESE. Town of Carlton to the west.

Anticline in the Paleoproterozoic Thomson Formation, near Jay Cooke State Park, Northeast #Minnesota. Deformation due to the
Penokean Orogeny, ca 1850–1900 Ma. This is a favorite fieldtrip stop; included in the GSA Centennial Guidebook. An October picture from the archives. #geology #FridayFold 🧪⚒️

#FridayFold

Bostie on rug for scale. Found in Connecticut this small chunk with a squiggle inclusion.

We hoped for a #FridayFold but I think we *mist* it. Fog off! ⚒️ #geology

Photo of a lake in green grass and a rock face behind it which is almost covered by fog.

Mount Baldwin, south of Mammoth Lakes in the #SierraNevada, in an area with some of the range’s most colorful, interesting, and rotten rock. (There’s a #FridayFold in there if you look carefully.)

There's no way the Bundesverband Geothermie fell for it and features this AI generated fake fold on their online encyclopedia. #geothermal #geology #FridayFold

Website screenshot of the Bundesverband Geothermie that shows an image of an AI generated fold used in their encyclopedia.

#FridayFold below the peak of Schilthorn mountain, Switzerland. #FoldFriday #Geology

A rocky mountain peak with green, rocky slopes, topped by a construction crane and buildings under cloudy skies, trees are visible in the foreground. Some geologic folds in the rocks.

#FridayFold! Punta das Cabras, Galicia (Western Asturian-Leonese Zone of the Variscan orogen), where one can find many striking examples of high-strain folding within shear zones. Recumbent to sheath fold in quartzites & micaschists in the basal part of the Cándana Gp. (Lower Cambrian) #geology ⚒️🧪

A photo of a fold, recumbent to sheath. A coin for scale.

#FoldFriday or is it #FridayFold ? Anyway , freshly bathed in this morning's early light, here's a lovely wee fold in kyanite-grade Moine schists above Loch Assapol in Mull. Fingertip at left for scale. 😊🥰 #Geology #Mull #Metamorphic

A view of a banded rock surface with stripes of pale and dark rock, each about the width of a finger. The central pale stripe shows a striking Z-shaped fold, but the others are straight up-and-down in the picture

#FridayFold An old picture of a limpet enjoying some beautiful folded greenschist-facies pelite in a rock pool near Thundergay, on the west coast of Arran. The pale bands are rich in fine-grained muscovite; the dark bands also have chlorite. The few rusty spots mark the position of pyrite crystals.

#Geology #Deformation #Folding #Metamorphic #Dalradian #Arran

A smooth clean rock surface in a rock pool showing pale and dark banding. There is a large V-shaped fold on the left, with the point of the V at the bottom of the image. A healthy-looking limpet sits on the rock in the centre of the field of view..

What day is today...? Time for #FridayFold In #Asturias (NW Spain), once part of the mighty Variscan orogen. A nice example of tightly folded Devonian turbiditic deposits. Cap lens for scale. Medium size geologist for scale. #geology #structuralgeology #science ⚒️🧪

A cliff, with tightly folded rocks. A woman in field clothes inspects the area.

We like fold-and-thrust belts, don't we? The Papuan Fold Belt, in Papua New Guinea, seen on Sentinel-1 radar data (18/2/2025), where the Darai Plateau is intersected by Mt. Bosavi. To the NE, the Strongly-Folded Belt, and the Imbricate Belt. #Geology #FridayFold #FoldFriday #RemoteSensing ⚒️🧪

Radar image (Sentinel-1) courtesy of Copernicus. PNG, the Papuan Fold Belt. Contains Copernicus Data (18/2/2025)

Folded Ketchepedrakee Amphibolite in east central Alabama. Nearby, magnetite quartzite is found that is thought to be the metamorphosed material deposited by deep sea hydrothermal vents. We call this kind of distinctive highly weathered amphibolite 'brickbat'.

#FridayFold #Geology #FridayFieldPhoto

rusty orange highly weathered rock face in a hillside. on the far right side is a long geologic hammer stuck in the soft material for scale. starting in the upper right and going to the lower left are several sawtooth shaped folds in the rock.

#FridayFold This is a fold in Carboniferous rocks at the Pastoratsberg in Essen, Germany. If you're lucky, it's not hidden by parked cars or overgrown in summer. ⚒️🧪

Photo of an outcrop and an antiform fold. It's about 3-4 m high, some plants almost overgrow the outcrop but it's still visible. There are different thin rock layers.

For #FridayFold : twisted flysch by the islet bridge, from our recent visit to #Gaztelugatxe

#FoldFriday

Twisted flysch layers, rotated to horizontal

The previous photo in context and with the actual current tilted orientation

The bridge in its stairway context as seen from the islet top. Other flysch is visible in the coastline background.

The Gaztelugatxe islet as seen from the fastland

A #FridayFold from the west coast of the #IsleofLewis.

The dark mafic #OuterHebrides dykes were intruded into the #Lewisian gneiss. The original cross cutting relationship has been brought into near concordance during subsequent #Laxfordian deformation which also generated these folds.

#FridayFold in #Archaean amphibolites seen on the west coast of the #IsleofLewis.

#FridayFold seen in a new road cutting near Stornoway.

#Archaean Lewisian gneiss is cut by mafic #OuterHebrides dyke. Both are then folded during the #Laxfordian.

Cross cutting of the gneissic foliation can be seen in the core of the fold, whilst the limbs are concordant.

Il n'y a pas que les roches sédimentaires ou métamorphiques qui présentent des plis, les roches magmatiques aussi ! Exemple avec ce pli dans la coulée de lave de Pietre Cotte (Vulcano, #Italie), mis en évidence par l'alternance de bandes de rhyolite (claires) et d'obsidienne (sombre).
#FridayFold #géologie

#FridayFold

Client Info