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Callan Bentley

@callanbentley.bsky.social

"bluebirds, bluegrass, blueschist, blue state, bluesky" Community college geology professor in Charlottesville, Virginia, USA

3,222 Followers  |  1,110 Following  |  3,084 Posts  |  Joined: 02.11.2023
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Posts by Callan Bentley (@callanbentley.bsky.social)

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Evening entertainment

01.03.2026 12:28 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

βš’οΈ

28.02.2026 20:11 β€” πŸ‘ 18    πŸ” 3    πŸ’¬ 0    πŸ“Œ 0

There is horror and evil and suffering in this world today, but it is beautiful and warm and sunny in central Virginia, and it feels like spring. I enjoyed a hike with my Geology Club and then did some chores. Now enjoying an IPA in the sunshine, and returning to the sad, sick news.

28.02.2026 18:48 β€” πŸ‘ 17    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Erika posted in earlier that it was from New Brunswick, Canada.

28.02.2026 12:40 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Friday fold: the Castile Formation at the State line outcrop - Mountain Beltway The Friday fold visits the Permian basin of west Texas. There, the Castile Formation exhibits gorgeous inter- and intra-bed folding.

Wow. That's uniformitarianism for ya!
mountainbeltway.all-geo.org/2014/06/20/f... βš’οΈ

28.02.2026 02:30 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

We have one. It's always empty. No one would want to hang out there.

27.02.2026 22:45 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Me at the beach holding out an ammonite fossil about 7 cm across with septa visible as wavy grey stripes.

Me at the beach holding out an ammonite fossil about 7 cm across with septa visible as wavy grey stripes.

Nice septa on show in this ~190 million year old ammonite I found it Whitby, North Yorkshire.

#FossilFriday #Paleontology

27.02.2026 19:29 β€” πŸ‘ 28    πŸ” 2    πŸ’¬ 1    πŸ“Œ 0

I look forward to visiting this summer, and paying thoughtful tribute to him when I am there.

27.02.2026 21:02 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Yes

27.02.2026 20:35 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

This unit, the Antietam Formation, is correlative with the "pipe rock" of the Ardvreck Group in NE Scotland: Cambrian passive margin transgression. Also, the Flathead sandstone, and the Tapeats of the western US (Rockies + Colorado Plateau). βš’οΈ

27.02.2026 20:05 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Yes, they are burrows: Skolithos.
They are darker because the sand around the burrow was more permeable, and hematite depositing fluids percolated more readily through that part of the rock. The color is diagenetic, not primary. βš’οΈ

27.02.2026 20:05 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
Quartz Pebble conglomerate

Quartz Pebble conglomerate

Rounded cobble of quartz sandstone with hematite highlighted Skolithos trace fossils

Rounded cobble of quartz sandstone with hematite highlighted Skolithos trace fossils

Some Chilhowee samples: Weverton at left, and Antietam at right. βš’οΈ

27.02.2026 18:28 β€” πŸ‘ 27    πŸ” 2    πŸ’¬ 1    πŸ“Œ 0

Probably Castile Formation from the TX/NM state line outcrop? The line in the middle looks more like a stylolite to my eye (rather than a fault). βš’οΈ

27.02.2026 13:48 β€” πŸ‘ 9    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0

Superb book. I look forward to this film adaptation!! βš’οΈ

27.02.2026 13:38 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Shiny wet outcrop of foliated rock with subhorizontal dip, brown water in front. A student in a hooded rain jacket gives it two thumbs up.

Shiny wet outcrop of foliated rock with subhorizontal dip, brown water in front. A student in a hooded rain jacket gives it two thumbs up.

Big kink folds in phyllite at Totier Creek Reservoir spillway near Scottsville, VA, on yesterday's (rainy) Physical Geology field trip:
#FridayFold
βš’οΈ

27.02.2026 11:24 β€” πŸ‘ 25    πŸ” 3    πŸ’¬ 0    πŸ“Œ 0

We do what we can, but if you have gigachipmunks of crushing that you need to accomplish on a tight deadline, this machine's capacity will need to be augmented by a second device.

27.02.2026 00:48 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Questions like, "How many chipmunks can I crush in 1 hour using this machine?"

26.02.2026 23:44 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
Close up of a dusty old die-cast machine that says BRAUN CHIPMUNK CRUSHER in raised capital letters.

Close up of a dusty old die-cast machine that says BRAUN CHIPMUNK CRUSHER in raised capital letters.

Found this machine today which seems suitable for most of your chipmunk-crushing needs:

26.02.2026 20:48 β€” πŸ‘ 23    πŸ” 1    πŸ’¬ 4    πŸ“Œ 0

Birding jargon

26.02.2026 17:43 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
A small gray owl with a V shaped face squints at the photographer from a hole in a wooden box.

A small gray owl with a V shaped face squints at the photographer from a hole in a wooden box.

Got an Eastern Screech-Owl (gray morph) today at Ivy Creek Natural Area in Charlottesville - roosting in a Wood Duck box! πŸ¦‰ #birds

26.02.2026 15:24 β€” πŸ‘ 21    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
Preview
DC geology - Google My Maps Geological sites in DC

www.google.com/maps/d/edit?...

26.02.2026 08:38 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Happy to help -- "METRO to Metamorphism"?

26.02.2026 08:28 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

They all want to go to Alaska now. They asked me to organize a field course up there!

25.02.2026 21:41 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

If your geology department needs an excellent guest speaker, see if you can get @julieelliott.bsky.social to talk. She gave a great seminar on various fascinating aspects of Alaskan tectonics today, from a geophysical, seismological, geomorphic, and volcanological point of view. Top notch! βš’οΈ

25.02.2026 19:07 β€” πŸ‘ 19    πŸ” 5    πŸ’¬ 1    πŸ“Œ 0
Macro photo of a brown stink bug in face view on a leaf, guarding a tightly-clustered bunch of eggs that are shaped and colored exactly like a full tray of dark beer with foam on top.

Macro photo of a brown stink bug in face view on a leaf, guarding a tightly-clustered bunch of eggs that are shaped and colored exactly like a full tray of dark beer with foam on top.

Finally, the bug is back with a round of the Guinness.

25.02.2026 01:59 β€” πŸ‘ 8228    πŸ” 1759    πŸ’¬ 93    πŸ“Œ 90
A fairly large slump on a grassy hillside: concave at the top (the scarp) and convex at the bottom (toe).

A fairly large slump on a grassy hillside: concave at the top (the scarp) and convex at the bottom (toe).

Talking landslides tonight with my field course students. Going to show them this 2017 slump photo from Camerino, Italy: βš’οΈ

24.02.2026 22:39 β€” πŸ‘ 34    πŸ” 3    πŸ’¬ 1    πŸ“Œ 0
PowerPoint slide showing faulted rock near the mouth of Mosaic Canyon in Death Valley. A student stands near the base of the outcrop to provide a sense of scale. The Hanging wall (upper block) and Foot wall (lower block) are labeled. A pair of half-arrows shows the hanging wall has moved down.

PowerPoint slide showing faulted rock near the mouth of Mosaic Canyon in Death Valley. A student stands near the base of the outcrop to provide a sense of scale. The Hanging wall (upper block) and Foot wall (lower block) are labeled. A pair of half-arrows shows the hanging wall has moved down.

Today's the day I wag my jaw about deformed rocks! βš’οΈ

24.02.2026 16:53 β€” πŸ‘ 37    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
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Hubble spotted a β€˜dark galaxy’ that’s at least 99.9% dark matter Search through space telescope’s archival images reveals unusually dim galaxy

Hubble spotted a β€˜dark galaxy’ that’s at least 99.9% dark matter | Science | AAAS πŸ”­πŸ§ͺ @science.org www.science.org/content/arti...

24.02.2026 10:09 β€” πŸ‘ 54    πŸ” 12    πŸ’¬ 2    πŸ“Œ 0

it's molting season for RFK Jr

24.02.2026 01:46 β€” πŸ‘ 6796    πŸ” 846    πŸ’¬ 101    πŸ“Œ 10
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GrΓ‘brΓ³karfell cinder cone, Iceland Explore this 1.28 gigapixel image.Lichen covers the slopes of a small cinder cone in southwestern Iceland. Taken from the rim of neighboring GrΓ‘brΓ³k.

Hey! I've been there. viewer.gigamacro.com/view/XmewwT8... βš’οΈ

23.02.2026 18:27 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0