Bill Lukens
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paleosol.bsky.social
Bill Lukens
@paleosol.bsky.social
660 followers 1.3K following 280 posts
geology | paleoclimatology | geochemistry | soils | sed/strat | Assoc. Prof. at JMU | views are my own

Lab website: https://sites.google.com/view/lukenslabjmu
Scholar profile: https://scholar.google.com/citations?user=Nlx0NacAAAAJ&hl=en&authuser=1&oi
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paleosol.bsky.social
We had a lovely #JMU Sed/Strat field trip yesterday, exploring Devonian strata in West Virginia that tell the story of the Acadian Orogeny.

We survived hail and bitter cold winds in the AM, giving way to sunshine, paleosols, and fluvial channels in the afternoon.

🧪⚒️🪨
A group of smiling students and their professor wearing earth tones and bright orange safety vests, in front of a red outcrop that contains mudstone on the lower 2/3 (with green drab halos around fossil burrows and roots) overtopped by a big, red channel sandstone. A geologist in bright orange and earth tones, doing the airplane dance (arms extended and leaning to the right) to indicate the tilt of bedding. In the background, a wall of fluvial sandstone contains lines dipping to the right, indicating bedding, and some more steeply inclined lines indicating lateral accretion sets in the meandering channels.
November 17, 2025 at 3:33 PM
paleosol.bsky.social
Recently I've been refreshing myself on #soil micromorphology.

Here is the suggested thin section sampling scheme from Fitzpatrick (1993). Eleven thin sections for one (1) soil profile.

lol sure my man, I'll just get one of those 50-yr mortgages to pay for that. 🧪⚒️🪨
A 3D rendering of a simple soil profile, with four horizons depicted as simple line drawings. A total of 11 rectangles representing thin sections are depicted.
November 14, 2025 at 7:53 PM
paleosol.bsky.social
Happy #SoupSeason to those who celebrate!

My mouth started watering when I was writing the alt text.
A red dutch oven filled with mutli-colored soup, includin coins of carrots, chunks of white potato, slices of bacon, and slices of celery, all topped with thyme and oregano. The soup liquid is a delicious golden yellow. Close-up image of carrot coin, bacon slices, potato chunks, and herbs.
November 11, 2025 at 2:51 PM
paleosol.bsky.social
Stacking up some coastal plain paleosols (fossil soils) for #FossilFriday. They're relatively immature and heavily overprinted with tectonic cleavage. Poor little guys.

Devonian Foreknobs Fm., Rt 33, West Virginia
(the runaway truck ramp outcrop)
🧪⚒️🪨
An outcrop of red mudstones, consisting of three crumbly intervals separated by thin, blocky sandstones, and a thick, purple-gray sandstone on top (to the right of image). A sign on the left edge of the image reads "State property no trespassing)". Green trees line the slope in the background.
November 7, 2025 at 2:07 PM
paleosol.bsky.social
Took my Sed/Strat class out to WV48 (Corridor H) for a lovely fall field trip Sunday. We had a blast examining the incredible paleo-Vertisols of the upper Devonian Hampshire Fm.

Pedogenic slickensides in 3D, root traces, plant fragments, and lots of burrows (lung fish?)!

I love #paleosols.

🪨⚒️🧪
Red mudstone rock with curvilinear fractures (pedogenic slickensides), thin, pale green squiggly lines (fossil root traces), and in the upper right corner there are tubu-like features interpreted to be burrows. Annotation of the first image. ss = slickenside.
November 3, 2025 at 8:03 PM
paleosol.bsky.social
A very #spooky northern black widow spider, chillin' under a boulder of Devonian Oriskany Sandstone near Berkeley Springs, WV. Gotta watch those hands when looking for brachiopod fossils!

Spotted during a family outing last weekend; highly recommend.
#spider #Halloween 🧪🪨
A scrunched up, shiny black spider with red dots down the back of its abdomen; the front-most dot is outlined in white. The background is a tan to black sandstone and the spider clings to the rock and a dirt-covered stick.
October 21, 2025 at 5:59 PM
paleosol.bsky.social
Bouma sequences, hot off the rock saw!

Upper Ordovician Martinsburg Fm. (Page Valley, VA) showing Ta-Tb-Tc. Sweet climbing ripples in the Tc.

Middle Devonian Millboro Fm. (Brandywine, WV) with Tb-Tc and silly, convolute bedding in the Tc and a nice weathering rind.

⚒️🪨🧪
A pale pinkish-white and hairy hand holding a gray rock showing the lower portion of a classic Bouma sequence. The lower 1/3 of the rock shows white, black and gray speckled medium sand finding upward (Ta), transitioning to fine sand in the middle 1/3 with planar bedding, and in the upper 1/3 there is fine to very fine sand with ripple cross-lamination. A pale pinkish-white and hand holding a gray rock showing the middle portion of a classic Bouma sequence. The lower 1/4 of the rock shows black and gray streaks representing planar bedding to ripple lamination. The upper 3/4 of the rock shows ripple lamination transitioning into convolute bedding, consisting swirled black and gray sediments. An orange and speckled-black weathering rind is visible on the left and bottom right of the rock. A rock saw is out of focus on the right side of the image in the background.
October 14, 2025 at 3:01 PM
paleosol.bsky.social
The Devonian Oriskany Fm. (quartz arenite with brachiopod molds) tightly folded, with the uppermost Devonian Helderberg Group (micritic/cherty limestone) in the armpit of the anticline.

Smokehole Canyon, WV

#FridayFold 🧪⚒️
Vertical layers of gray rock on the left and right, with the strata tightly folded in the middle of the image (forming a tight anticline). Green vegetation shrouds much of the outcrop, and the north fork of the Potomac River is visible in the foreground. Same image as the first, with yellow lines tracing the fold and text overlain to indicate the location of the Oriskany Fm. and Helderberg Group.
October 3, 2025 at 3:29 PM
paleosol.bsky.social
The 2025 Google Earth imagery is wild. We live on such an astoundingly beautiful planet.

Namibia (-23.6551610, 15.2430470). Close-up and wider view. In wide view: a structural dome popping out to say hello. Note the different eolian sediment compositions to N and S of the stream channel.

🧪⚒️🪨
Google Earth satellite image showing a sinuous, ephemeral (currently dry), braided stream that is pale gray with trees within the channel. Red eolian sands are to the south (bottom) of the stream, whereas folded, black bedrock mantled with light brown to tan sediment lies north (top) of the stream. A red eolian dune field to the south (bottom) of a sinuous, dark line marking a stream channel. To the north (upper half) is a desert of variagated back bedrock and light tan sediment. There is a dome popping out of the ground, looking like an eyeball, in the middle, upper 1/3 of the shot.
October 1, 2025 at 5:51 PM
paleosol.bsky.social
What in the world is up with these wild, incised meanders? They have about about 75 m relief with the surrounding terrace.

Iran might have the coolest geology on the planet.

28°06'02"N 59°59'17"E

#geology #geomorphology 🪨🧪⚒️
A satellite picture of gray-brown sediment with sinuous lines of tan to white wiggling across the screen from side to side, representing incised river channels. A satellite picture of gray-brown sediment with a closeup of a sinuous line of tan to white wiggling across the screen from side to side, representing an incised river channel. A dark gray landscape cross-cut by branches of light tan to white. Many branching, nascent stream channels with tiny tributaries flow from right to left, all cross-cut by wider, light gray to white, sinuous stream channels.
September 29, 2025 at 1:51 AM
paleosol.bsky.social
Some action shots from today's lab: students surveying channel slope on the Em3 stream table, and the beautiful, swirled patterns of a meandering stream channel in disequilibrium. ⚒️🧪🪨
A group of geology students using a small, red ruler and silver cross-bar to survey the slope of a model river channel in a stream table. The stream table is an aluminum, boat-shaped basin with yellow, white, black, and red plastic grains. Yellow, black, and white sediment grains forming swirled patterns of a meandering river model system.
September 26, 2025 at 5:42 PM
paleosol.bsky.social
This one is gonna be a nail-biter, folks! Personally, I'm all in for the little green alien mineral.

#MinCup25
Current results of the mineral cup 2025. Kosmochlor has 484 votes, Azurite has 483 votes.
September 9, 2025 at 2:40 PM
paleosol.bsky.social
Nate Silver's framing of #BlueSkyism is just a skill issue. It's quite a lovely place over here on my feed.
September 5, 2025 at 7:42 PM
paleosol.bsky.social
#Silver #MinCup25
A hand holding a can of Coors Light, the silver bullet
September 5, 2025 at 3:18 PM
paleosol.bsky.social
#Okenite for the win baby!

What a weird little phyllosilicate. Where's your aluminum, little buddy?

#MinCup25 🪨🧪
A white cotton-ball looking mineral with poorly drawn googly eyes. The background consists of smaller, tan crystals that look like cauliflower.
September 2, 2025 at 1:25 PM
paleosol.bsky.social
How about this example of the short-term carbon cycle... 👍

(Copilot prompt: "Draw a box diagram of Earth's short-term carbon cycle, with the important sources, sinks, and fluxes labeled.")
August 15, 2025 at 7:27 PM
paleosol.bsky.social
For #FossilFriday here is the 1986 FJ60 that I used to roll around in during grad school. I miss it dearly.
A 1986 Toyota Landcruiser with multi-tone paint, red on the top and a yellow to orange fade on the bottom, and beige panel along the lowest edge of the doors and front quarter panel. It is golden hour and trees are light up by the settings in the background.
August 15, 2025 at 6:55 PM
paleosol.bsky.social
Good morning. While on a road trip this summer, I stumbled upon a "cool S" just north of the PA turnpike near Bedford.

Thank you to the Devonian Hamilton Group, Alleghenian deformation, and subsequent exhumation for constructing this homage to the 90s.

🪨 #geology #coolS #bedrock
Terrain map from Google Maps showing ridges in bedrock that look like the "cool S" from the 90s. Route 99 runs north-south on the western side of the image, route 76 (PA Turnpike) runs southeast-northwest along the lower left corner of the image. Bedford PA is just southwest of the Turnpike along the lower left side of the image. Black lines overlain on first image, tracing the "cool S" from the 90s.
August 11, 2025 at 2:29 PM
paleosol.bsky.social
Oh baby it's on! Oscillation ripples are happening right now in the stream table!

⚒️🧪
August 8, 2025 at 3:59 PM
paleosol.bsky.social
Another fun test: meander cutoffs and river-dominated delta progradation.

In-channel L-bars are visible in the stream channels and migrate down-slope.

X-secs of coarsening-upward prograding delta lobes are also discernible.
EM3 stream table with a meandering river leading down to a river-dominated delta. The delta lobes and river channel bottoms have mostly yellow sediment (coarsest), with streaks of finer black and white sediment in minor channels and channel margins. EM3 stream table with a meandering river channel, featuring a chute cutoff and streaks of coarse, yellow sediment along in-channel bars (L-bars mostly). EM3 stream table with a cross-section of a prograding delta lobe. Internal strata are yellow-white/black-yellow, showing a delta lobe that migrated away and then back again. Basin-dipping strata dip down and to the right.
August 7, 2025 at 5:30 PM
paleosol.bsky.social
Testing out a coastal processes experiment, featuring longshore drift and prograding shorelines using a WaveMaker oriented obliquely to shoreline.

coarse -> fine seds = yellow > white > black > red
EM3 stream table with a shoreline of yellow, white, black, and red sediment. The shoreline forms an arc toward the background of the picture, with a small embayment being encroached upon by yellow sands. Black, white, and red sediment is mostly offshore. EM3 stream table with a shoreline of yellow, white, black, and red sediment. The shoreline of yellow grains prograded counter-clockwise and overtopped offshore sediment. Finer white, black, and red sediment also prograded into the basin.
August 7, 2025 at 5:30 PM
paleosol.bsky.social
Whenever I try to move my own files on a PC...

#AcademicSky
The "is this a pigeon meme". A butterfly floating in the air is labeled "A file I created seconds ago" and the man gesturing to the butterfly is labeled "Windows: ThIs FiLe MiGhT bE hArMfUl To YeR cOmPuTeR"
July 31, 2025 at 4:30 PM
paleosol.bsky.social
Ah yes, those stinkin oil and energy companies that only fund research linking fossil fuels to climate change...
A quote from the FAQ page of the scam website globalweatheroscillations.com: "Question... Your company indicated that no grants or outside funding were received for this research. Why is this? Answer... During the past few years, federal grants to study natural cycles were not available. Other entities such as oil and energy companies likewise were not issuing grants, mainly because it was politically correct to stick to the mainstream thinking that global warming is almost entirely caused by the burning of fossil fuels."
July 14, 2025 at 8:44 PM
paleosol.bsky.social
Found some cool baby snake skeletons while re-insulating the joist bays in my crawlspace this weekend. They are teeny-tiny.

(the crawlspace is fully encapsulated and actually quite nice, but little pill bugs and I guess tiny snakes get in somehow)
A tiny, tan-colored snake skeleton consisting of many attached vertebrae and a very small snake skull, on top of a human hand. Zoomed in so far you can see the human hand print ridges. A tiny, tan-colored snake skeleton consisting of many attached vertebrae and a very small snake skull, on top of a human hand. The snake skeleton is in the center of the palm of the hand and is approximately 1.5 inches long.
July 14, 2025 at 5:03 PM
paleosol.bsky.social
If they more or less maintain NSF's funding level, they can put the new FBI headquarters in my back yard, rent-free for 99 years. Caveat: they have about 1/6 of an acre to work with.
Congress’s annual process of setting 2026 spending levels for federal agencies has only just begun, but today the Senate appropriations committee voiced its intent to ignore the request by President Donald Trump to slash the budgets of the National Science Foundation (NSF) and NASA science programs. Instead, the panel supported maintaining spending at essentially current levels. The committee’s preliminary vote today on the Commerce, Justice, Science, and Related Agencies (CJS) Appropriation bill is the latest indication that Congress doesn’t plan to simply rubber stamp Trump’s proposal to cut federal research budgets for next year. (The bill’s final passage has been temporarily stalled by a partisan fight over a new location for FBI headquarters.) Under the bill, NSF’s budget would take a tiny $60 million hit, to $9 billion, rather than plunge by 57%, to $3.9 billion, as Trump proposed. With $9 billion, NSF would likely be able to protect a new directorate that promotes applied research partnerships with nonfederal entities, and avoid cuts to its several other research directorates.
July 11, 2025 at 7:25 PM