iiinova — where your digital self keeps evolving

Lil Boo-kens 👻 @paleosol.bsky.social · 04/10/2026

Haven't had a chance to visit that site yet (sadly!). Lower right of photo 1 looks like a partial x-sec through a calcite vein. Joe's might be right (partially cemented burrows), but I'd need to see it in person. Maybe freshwater muscles/bivalves?

Lil Boo-kens 👻 @paleosol.bsky.social · 03/10/2026

Grading sed/strat exams and someone referred to a quartz arenite's cement as "silicone" (instead of silica). 🤭 ⚒️

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Lil Boo-kens 👻 @paleosol.bsky.social · 02/10/2026

Today the #JMU Sed/Strat class continued our experiments with meandering river cutoffs using the EmRiver Em3 stream table. This second group had A LOT of fun playing with the stream table once their work was done. 😆 @emriver.bsky.social ⚒️🧪 youtu.be/nguqgi3grq8

youtu.be

Meandering River Cutoff Experiment 10/02/26

YouTube video by JMUSedStrat

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Lil Boo-kens 👻 @paleosol.bsky.social · 02/10/2026

I'd like to congratulate #Quartz on winning #MinCup26. ⚒️ Reliable without flare. Will travel long distances, but only at moderate speeds. Can be many colors but often isn't. You truly are the 1999 Toyota Corolla of minerals.

A photography of a gray 1999 Toyota Corolla, the most boring car ever conceived, lacking hub caps and parked in from of a very simple playground on an autumn day. Even the parking lot lines have faded out of resignation to a long life of boredom.
Photograph by Brian Reider.

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Something I love about this stream table is that the plastic sediment mostly acts like bedload, but also behaves in fundamentally different ways (e.g., bigger grains are more easily transported). This provides ample opportunity for students to reflect on how model systems differ from the realworld.

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The students also measure slope and sinuosity of 10 modern rivers using Google Earth. This project culminates into a midterm paper that incorporates their experiment and the modern reference data. The key take-away messages involve both fluvial dynamics and the nature of model systems.

The class splits into two groups for this project. Each group will take a turn examining a sinuous river under 'background' conditions, followed by an induced chute cutoff event. Before and after the event, students measure the stream profile (to estimate channel slope) and quantify sinuosity.

Photo of geology students standing around an aluminum stream table filled with yellow, white, black and red plastic sediment. The students are using a level and measuring tape to measure the slope and sinuosity of a model river.

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Meandering River Cutoff Experiment 9/30/26

Today the #JMU Sed/Strat class begin our experiments with meandering river cutoffs using the EmRiver Em3 stream table. @emriver.bsky.social ⚒️🧪 www.youtube.com/watch?v=GmRj...

youtube.com

YouTube video by JMUSedStrat

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This bag of rubber bands gave me a serious hankering for pappardelle.

A bag full of wide rubber bands that look like delicious pasta.

Randall Munroe @xkcd.com · 29/09/2026

Reposted by Lil Boo-kens 👻

Slab Graveyard xkcd.com/3303/

4-panel comic. (1) PERSON 1: Any plans for Halloween? PERSON 2 with beret: Me and my friends are gonna check out a slab graveyard! (2) PERSON 1: What’s that? PERSON 2: When dense crust subducts, geologists think it might pile up at the bottom of the mantle. [illustration of Person 2’s related theory] (3) PERSON 2: We’re going to hide in the crust and ride it down to see. Wanna come? It’s gonna be spooky! (4) PERSON 1: Won’t that take millions of years? PERSON 2: Lots of time for ghost stories! PERSON 1: I think I’m good. PERSON 2: Too spooky? I understand.

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My classes are 75 min long. So if the exam is meant to be completed in ~45 minutes, that's ample room for 1.5x time accommodations for students who don't take the exams in the testing center.

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And to be clear, the lecture content is woven into in-class activities and online reinforcement homework. So students do get assessed (on their understanding and their ability to apply concepts in to new ways. It's just not always on an exam.

My GenEd exams are pretty short and contain a representative, but not comprehensive, subset of material. But b/c a good chunk of content is not on exams (for brevity), some folks think that equates to the omitted content being trivial or extraneous. Kind of a weird take, no? #AcademicSky

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A kinda similar phenomenon is my favorite linguistic thing ever: the eggcorn. It’s a mistake that happens to work anyway. en.wikipedia.org/wiki/Eggcorn...

en.wikipedia.org

Eggcorn - Wikipedia

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Lil Boo-kens 👻 @paleosol.bsky.social · 25/09/2026

Perhaps the most accurate description of Reddit that ever existed…

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For this #FossilFriday, here is the bottom of a thin, little turbidite deposit. The sole marks include tool marks from nautiloids, with at least one visible at the end of the tool mark.

The bottom of a gray rock (lithic wacke) with grooves all over it, mostly trending from upper right to lower left. These are tool marks made by nautilus shells scraping the sea floor.

Close up photo of a tool mark with a nautilus shells scraping impression at the end of it (yellow arrow).

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Lil Boo-kens 👻 @paleosol.bsky.social · 25/09/2026

I'm waving out my office window, you just have to zoom in really really far to see me.

Lil Boo-kens 👻 @paleosol.bsky.social · 25/09/2026

This is the most egregiously unnecessary cubic spline I’ve ever seen in my life. 🥴 🧪📊

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Lil Boo-kens 👻 @paleosol.bsky.social · 24/09/2026

It's a big tent, so come on in, Archeologists! My only quibble, as a deep-time paleoclimate researcher, is that we usually refer to "deep-time" as Earth history before the Quaternary (i.e., prior to 2.58 Ma). Although thousands of years before present is old for archeo folks, it's young for us!

Lil Boo-kens 👻 @paleosol.bsky.social · 22/09/2026

New form of anguish, by OneDrive: Anguish+ Email attachments cannot download, but you can save them to OneDrive. 🤗 Open OneDrive -> cannot load files -> close OneDrive Open OneDrive -> files load -> sort by most recent -> show from 2022 and earlier -> close OneDrive. Cool.

Lil Boo-kens 👻 @paleosol.bsky.social · 22/09/2026

It's a rainy, chilly morning in the Shenandoah Valley. My toddler loves the rain, so he was the most excited, cheery person within about 1000 square miles.

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I'd also like to give Dr. Ellen Miller a shoutout - she's been working at Buluk for many years and is a lovely colleague. The road to Buluk is about 5 hours of dust and heat, and she does it every summer.

Five geologists/paleontologists who are covered in dust after a 5 hour ride out to the field area.

We still have much to learn about whether or how the Miocene Climate Optimum affected low latitude, terrestrial areas. This has been a fun decade of analysis and writing since fieldwork in 2016! Thanks esp. to @danpeppe.bsky.social for digging a monster trench in the field.

A tan hill in a desert, with an armed guard at the top and Dr. Daniel J. Peppe collecting paleomag samples in one heck of a trench going straight up the outcrop.

A fun finding - when you combine independent proxy results (soil bulk geochem for rainfall, clumped isotopes for temperature), you can plot the data on a biome diagram. These independent measures confirm our traditional stable isotope findings of an open woodland to savanna being present.

Biome diagram, showing mean annual precipitation versus mean annual temperature. The combined values plot as biomes on Earth today. The yellow dots overlain on "savanna" and "thorn scrub", which are woodlands in other definitions, are our best estimates.

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What I think is going on: carbonates form when soils dry out (usually). In monsoonal areas, this occurs at the end of the wet season, coinciding with a ramp up in C4 biomass growth. I think the carbonates are more sensitive to minor C4 plant components. Or... we need to go back to the drawing board.

We vetted the carbonates using field observations, thin section analysis, and clumped isotope analysis. These are among the most carefully vetted samples in the East African Rift System record. Throwing out unexpected values here would suggest we throw out 1000s of previously measured data, right?

Cross-plots and violin plots of stable isotope data measured on pedogenic carbonates.

What about the plants? Stable isotopes measured on bulk organics and leaf wax extracts are exactly what we would expect for C3 plants growing in open-canopy conditions (not forests or water stressed). However, carbonate isotopes are way higher, suggesting C4 plants - tropical grasses. What gives?

Four columns showing stable isotope analyses by stratigraphic meter level. In order: organic matter, n-alkane C31, n-alkane C-35, and pedogenic carbonate data.

We used paleosol bulk geochemistry to estimate mean annual rainfall, pinning the site to "subhumid" conditions - too dry for forests, too wet for grasslands. Carbonate clumped isotopes tell us the soil temps were similar to the modern Serengeti. The MCO was wetter, not hotter, than Turkana today.

Three plots and a series of four maps. The graphs have color-coded symbols showing paleoclimate proxy results. The maps are MioMIP model simulation output, with yellow-blue color ramp zones overlain on the continent of Africa.

In paper 2, we dove into the details of the paleosols! They formed on floodplains with seasonally varying water budgets, quite similar to modern Vertisols in monsoon-affected areas. Many gorgeous root traces, carbonate nodules, and iron concretions. pubs.geoscienceworld.org/gsa/gsabulle...

The "paleosol yearbook photos." Nine outcrop photos of paleosol samples or profiles, showing reds, orange, maroon, brown, and light green to tan colors.

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We also described the sedimentary facies and found that most of the site is a meandering river complex, with silicified logs in the channels. One river even migrated into a basalt flow, with chunks of basalt rolled into the channel base.

Panoramic photos of outcrops at Buluk, with associated facies overlays.

A gray chunk of basalt, with a rock hammer for scale. The basalt flow is in the distance (back left of photo), overlying red floodplain mudstones. This photo is take at the base of a tan fluvial channel.

Dr. Katie Loughney contributed taphonomic analyses of fossils from one major site at Buluk. She found evidence for scavenging (even nibbling!) on bones and abrasion suggesting a clearly mixed/filtered assemblage. Caveats for interps of faunal community and diets, etc., from these fossils!

Six photographs of fossil bones with a black background. The bones show evidence for insect borings and mammal tooth marks and abrasion.

Geochronology and sedimentology of the Buluk fossil site, East Turkana, Kenya: Hominoid fossil–bearing strata within the Miocene climate optimum | GSA Bulletin | GeoScienceWorld

In paper 1, we used Ar/Ar and paleomagnetism to situate major ape and monkey fossil sites to be 16.6-16.11 Ma, within the Miocene Climate Optimum. The MCO is the last time CO2 was as high as today/near future. There are fleetingly few MCO sites in Africa. pubs.geoscienceworld.org/gsa/gsabulle...

pubs.geoscienceworld.org

The Buluk Member of the Bakate Formation in the eastern Turkana Basin of northern Kenya includes the remarkable Buluk fossil site that preserves the

Two new papers: we re-dated the Buluk fossil site in Turkana, Kenya, and applied proxies to reconstruct climate and vegetation. Out now in GSA Bulletin! @danpeppe.bsky.social @munyaka.bsky.social @kevinuno.bsky.social @geosociety.bsky.social #MammalMonday #isotope #GSAPubs 🧪⚒️🌱🌦️🐒

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Lil Boo-kens 👻 @paleosol.bsky.social · 20/09/2026

A simple, quick adaptation would be to use real grass (as the World Cup required in NFL stadiums). Transpiration cools down leaves, which plastic turf cannot do. Perhaps this is the example that will help my #GenEd students understand latent heat? 🧪

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Corrected alt text for the first two photos: these are dewatering structures (autocorrect mistake)

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Lil Boo-kens 👻 @paleosol.bsky.social · 19/09/2026

Gorgeous day for geology in Page Valley, VA! Our Sed/Strat class enjoyed turbidites of the late Ordovician Martinsburg Fm and braided stream deposits of the Silurian Massanutten Fm #JMU ⚒️🧪

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Ok I started looking up specific subs. The USS Peto, first of the Manitowac subs, went through the Panama Canal and on to Australia.

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I’ve been thinking about this for a week now. Did any of the Manitowac submarines go to the Pacific theater, or were all bound for the Atlantic? I’m wondering what route a sub would take to the Pacific if not built on the west coast. Anything I can find skips right to their patrol routes.

“…the surface temperature at which precipitation peaks ranges from 300–360 K” That goes from quite hot to, er, insane, but the lower end does overlap prior hothouse states.

One of the most succinct, clear abstracts I’ve read in some time. Rather delightful.

Lil Boo-kens 👻 @paleosol.bsky.social · 17/09/2026

I find exhumed soils (a type of paleosol) to be very entertaining. It’s like the profile took a break for awhile and then said “Ok, where were we? That’s right, *weathering*!”