Callan Bentley
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callanbentley.bsky.social
Callan Bentley
@callanbentley.bsky.social
3.1K followers 1.1K following 2.7K posts
"bluebirds, bluegrass, blueschist, bluesky"
Community college geology professor in Charlottesville, Virginia, USA
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callanbentley.bsky.social
Guess what our topic is in Physical Geology class today? ⚒️
A photograph of a lab.wall and table with a monitor showing a photograph of a banana split.
November 19, 2025 at 2:31 PM
callanbentley.bsky.social
Taking bets for: May maximum 2026. ⚒️
Graph showing the past two years of the Scripps "Keeling Curve" Mauna Loa CO2 data. Each year (2024 & 2025) the numbers peak in May, and reach a minimum in September. May 2024 ~427 ppm, Sept 2024 ~421 ppm, May 2025 ~430 ppm, Sept 428 ppm.
November 16, 2025 at 9:09 PM
callanbentley.bsky.social
Porphyritic and (I think) spherulitic ... So not a tuff.
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Not sure how to answer the "recovery" question: please clarify?
Close up of the core, showing a gleam of a reflected light off of the watery film spritzed onto it. Also, potassium feldspar phenocrysts, and a patchy series of oval shapes that is repeated many times
November 16, 2025 at 12:41 AM
callanbentley.bsky.social
Exciting new discovery in core drilled east of Charlottesville - a rhyolite within the greenstone! This should provide a valuable U/Pb date from its zircons. ⚒️
Photograph of a box of five rock cores, three of which show Catoctin greenstone with stretched chlorite-filled amygdules, but the second-from left shows pink/tan rhyolite at the bottom, and the left-most core is 100% rhyolite, featuring K-spar phenocrysts and a spherulitic texture in the center of the core. All the cores have been misted with water to make them look better.
November 15, 2025 at 2:12 PM
callanbentley.bsky.social
Here's what you are missing... ⚒️
November 14, 2025 at 11:33 PM
callanbentley.bsky.social
Visiting Boscobel Quarry today. ⚒️
Half a dozen benches down in a granite quarry, with a large haul truck receiving broken granite from a loader. An African American student looks through a hand lens at a sample of granite. They have dredlocks, and their sunglasses are pushed up on their forehead. Brightly lit quarry wall. Horizontal gneissic banding is visible.
November 14, 2025 at 10:44 PM
callanbentley.bsky.social
Picking through the core discard pile at Luck Stone's Boscobel Quarry. ⚒️
Five geology students behind a GIANT pile of white rock cores.
November 14, 2025 at 8:26 PM
callanbentley.bsky.social
Geopetal gastropods from Mississippian Reynolds limestone. #FossilFriday
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Weathered limestone showing snail shells in cross section partly filled by light gray sediment and partly filled with darker coarsely crystalline calcite spar. Pencil tip for scale.
November 14, 2025 at 4:32 PM
callanbentley.bsky.social
Represented STEMSEAS @ the UNOLS mtg in Alexandria. 1 of my Alaskan cruise mentees shared her geology conversion experience w/ the crowd. She, STEMSEAS co-PI Sharon Cooper, & I demonstrated the program's vitality for utilizing transits of the US academic research fleet for changing student lives. ⚒️🌊
A STEMSEAS alumna recounts how important her cruise in Alaska was for motivating her to pursue geology at Wellesley. A STEMSEAS faculty mentor (Callan), PI (Sharon Cooper), and student mentee all gather for a group portrait selfie at a post-meeting reception in a brick lined bar.
November 13, 2025 at 1:31 AM
callanbentley.bsky.social
It's that most meandering time of the semester.
@emriver.bsky.social
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November 10, 2025 at 7:58 PM
callanbentley.bsky.social
A few more shots from Belle Isle today. ⚒️
Virginia Commonwealth University professor James Vonesh talks about pothole ecology with PVCC geology students. Callan explains magmatic flow banding (schlieren) in the Petersburg Granite to the students and uses a Brunton compass to measure its orientation. Multiple pairs of legs standing around a pavement outcrop showing an almost circular foliated xenolith, bracketed by schleiren.
November 9, 2025 at 8:22 PM
callanbentley.bsky.social
Exploring potholes at Belle Isle in Richmond.⚒️
Callan perks out of a large (dry) pothole while five of his students dangle their legs in.
November 9, 2025 at 5:01 PM
callanbentley.bsky.social
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GEOLOGY FOR EARTHLINGS in the style of the sign ZOHRAN FOR NEW YORK CITY
November 9, 2025 at 11:41 AM
callanbentley.bsky.social
Two piscivorous #birds seen today on the Rivanna River. 🦉
Great blue heron standing in some small rapids between large boulders. Belted kingfisher on a power line.
November 9, 2025 at 12:17 AM
callanbentley.bsky.social
Inspired by Rebecca Solnit's "Wanderlust," I took Pickles for a walk this afternoon and she got to play in Buck Mountain Creek. 1.5 miles & we didn't see a single car, another human, or another dog.
Black dog half submerged in clear creek water.
November 7, 2025 at 8:57 PM
callanbentley.bsky.social
A shot of some lovely crumples -- the #FridayFold -- from the flanks of the Cristo Rey laccolith in w.TX / s.NM. Here, Cretaceous aged shale and sandstone of the Mesilla Valley Formation slid off the adjacent bulge of Eocene magma, piling up in chaotic folds as they moved. ⚒️
A wide hillside, sparsely vegetated, with a geologist in the middle to provide a sense of scale. The field of view is about 60' tall and 100' wide. Cropping out are dozens of folds of various interlimb angles and orientations.
November 7, 2025 at 6:19 PM
callanbentley.bsky.social
Fantastic new slab of eensy little sea urchin fossils from Oregon, courtesy of @smilodonichthys.bsky.social #FossilFriday ⚒️
A slab of rock about the length of a pencil, light gray in color, with orange circular fuzzy bordered fossils, and lots of little orange lines higgledy piggledy all over the slab. Pencil for scale.
November 7, 2025 at 1:30 PM
callanbentley.bsky.social
Second November praying mantis I've seen this week!
A medium sized gray praying mantis on a brick wall. Its pseudopupils look like cartoon googly eyes.
November 5, 2025 at 7:45 PM
callanbentley.bsky.social
What a relief. 💙
Map of Virginia (screenshotted from the New York Times website) showing shift in voting margins since the 2024 presidential election. Almost every county & municipality in the Commonwealth shifted towards a more Democratic result.
November 5, 2025 at 11:42 AM
callanbentley.bsky.social
Colors 🍁
Burning bush in fall foliage in the foreground with other colorful trees and shrubs in the background out of focus
November 3, 2025 at 10:34 PM
callanbentley.bsky.social
Top cloud of the day. ☁️
Blue sky with fall foliage trees framing it. A ^ shaped cloud is all alone by itself
November 3, 2025 at 3:24 PM
callanbentley.bsky.social
Adjusting to the new sunset time.
Fire with camp chairs and a sunset in the background
November 2, 2025 at 10:19 PM
callanbentley.bsky.social
A little autumn beauty from my walk this morning.
Forested hills with trees in autumn colors, above a brown field of grass. A white farmhouse stands where the hills meet the lowlands.
November 2, 2025 at 4:39 PM
callanbentley.bsky.social
Cleaning the kitchen today, and realized that my favorite kitchen knife is one I spent ~$3 on at the IKEA in College Park, MD, 25 years ago.
Three knives on a magnetic knife holder on a wall. There is a long knife with a curved top and a straight blade, a medium sized knife with a triangular point, and a cleaver.
November 1, 2025 at 4:59 PM
callanbentley.bsky.social
Siccar Point is a touchstone in the evolution of geological thinking: the spot where a human mind first reeled at the depths of geologic time. Visiting it was profound, connecting across the centuries with James Hutton and John Playfair, who connected across the eons with the age of the Earth. ⚒️
Callan at Siccar Point angular unconformity, wearing a bright orange t-shirt and khaki pants, with his left hand on the graywacke and his right hand on the base of the Old Red Sandstone.
November 1, 2025 at 12:02 PM