Congratulations to newly minted Dr. @mcolinmarvin.bsky.social and Dr. Michael Hasson! I feel so lucky to have had you both as my first PhD students. Can’t wait to witness your next discoveries! #geomorphology #sedimentology #graduates #PhD @stanforddoerr.bsky.social

The January 2026 issue of #Geology is available online. Scanning electron microscope images of zircon sand grains from Algodones Dunes, California, USA. Read the full issue: geosociety.co/Geology_Jan26#Geology#GSAPubs Photo by M. Colin Marvin.

Were Earth's deep oceans better oxygenated during the Tonian than later in the Neoproterozoic? New thallium isotope data suggest they were. Check out our new paper in Geology: doi.org/10.1130/G536...

Cool contrasting collapse patterns side by side on the leeward side of the crest of a sand dune in Mesquite Flats. ⚒️

@mcolinmarvin.bsky.social next explored if—and why—aeolian #dune fields, like rivers, reach a near-transport threshold state. This work has neat implications for reconstructions of wind conditions on the early #Earth and on other #planetary surfaces (12/17 am, EP31D-1678)

check out EP33A at 2:15 in Rm. 255 to see some fantastic talks on flows (especially winds!) on Earth and other planets!

Some chemists build molecules incrementally. Others make risky moves to discover new chemistry. Both succeed. We call it methodology. But it's style. And we act like acknowledging different approaches threatens scientific rigor.

What would you share with an earlier version of yourself?

Did you know sand grains record their transport history? New research in Geology shows zircon grains reveal their journey through microscopic abrasion “microtextures”—even in billion-year-old rocks! Read more: geosociety.co/4oHG2J6 #Geology #GSAPubs

take a sec to check out our paper on zircon micro-abrasion features and what they can tell us about Earth’s surface billions of years ago (hot of the proverbial press in @geosociety.bsky.social)!

Yooo how about those Mariners??!!!

Just out: PhD candidate @mcolinmarvin.bsky.social shows that like in quartz, #zircon grains preserve microscopic archives of their transport history. But unlike in quartz, those archives remain decipherable for billions of years, unlocking first 90% of #Earth ’s history @stanforddoerr.bsky.social

Did you know that sand records its transport history as it moves across Earth's surface? We developed a new tool to investigate billion-year-old rocks by looking at microscopic features on zircon sand grains. Check out our new paper in @geosociety.bsky.social to see how! doi.org/10.1130/G537...

eBook Preview Statistical Physics of Rarefied Sediment Particle Motions and Transport: Applications to Hillslopes and Rivers Posting this preview of material from my next (unfinished) book might be a mistake. But eh… what the hell. 1/n cdn.vanderbilt.edu/t2-my/my-prd...

Findings from a recent study could upend the conventional view of how rivers have shaped continents over time. It’s “a significant revision to our understanding of the history of the Earth,” said lead author Michael Hasson. @marslogander.bsky.social

So proud of Michael!! 😎 This work was a collaboration with @alvitello.bsky.social at @unipd.bsky.social and A. Ielpi and @ubcokanagan.bsky.social Check also: - Perspective by J. Pizzuto: doi.org/10.1126/scie... - Stanford’s press release: sustainability.stanford.edu/news/rise-pl...

Plants change how river bends move - paper by PhD student Michael Hasson out as First Release in #Science!! Paper: doi.org/10.1126/scie... Before #plants, #meanders did not grow laterally as much but translated downstream, making them look like braided rivers in rocks. @stanforddoerr.bsky.social

Sand grains from Coral Pink Sand Dunes State Park, Utah 🧪⚒️

Tonight is the 250th anniversary of Paul Revere’s midnight ride. May his memory remind us all to resist the tyranny forming in our government.

Postdoc Carlos Alvarez shows that Mars’s large #aeolian #ripples are not impact ripples through low-pressure #wind tunnel experiments at #NASA Ames. Very excited about this one! @stanforddoerr.bsky.social www.nature.com/articles/s41...

PhD student Sophie Silver's first paper shows that crack geometry betrays presence of water on other planets! www.pnas.org/doi/10.1073/... There's a nice write up in Penn Today here: penntoday.upenn.edu/news/penn-ca...

New paper by PhD student @mcolinmarvin.bsky.social uses #patterns formed by #dunes to better understand sources, pathways, and sinks of #sand on #Titan. Spoiler: #Xanadu has outsized influence on #eolian sediments, and sand travels far!! @stanforddoerr.bsky.social

Check out our paper in @agu.org where we provide evidence for a continuous transport pathway around Titan’s equatorial dune fields, only interrupted by the Xanadu region (with implications for the nature of Titan’s sand grains!) agupubs.onlinelibrary.wiley.com/doi/full/10....

8th International Planetary Dunes Workshop is held in Sassari/Alghero, Italy, from 19–22 May: www.hou.usra.edu/meetings/dun... 🔔 Important Deadlines: 📌 Abstract submission: 12 March 📌 Registration: 31 March

Mars Wore Blue Velvet The dark-blue and purple colors indicate coarse-grained sands that are comprised of basalt, an iron and magnesium-rich volcanic rock that formed from cooled lava millions of years ago. uahirise.org/hipod/ESP_05... NASA/JPL-Caltech/University of Arizona #Mars #NASA #science

Had a wonderful time today! It was really great meeting you and thank for the invite to visit your fantastic department (and beautiful campus!)

dune find of the day: laterally linked and lone barchans in the Bodélé Depression, Chad (near 17.12°N, 17.87°E)

Final stop with postdoc Carlos Alvarez on the "Aerodynamic #roughness of rippled beds under active #saltation at low atmospheric #pressure" (EP54A-03, 146 B). Fr 4:20-4:30 pm. #Wind tunnel work reveals impact of #bedforms and #saltation on #Mars. #AGU24 (10/10)

Back to #Mars with PhD student Claire Blaske asking "Were #boulder fields along Mars' putative #ocean paleoshoreline deposited by a #tsunami?" (EP51B-06, 146 B). Fr 9:25-9:35 am. Or perhaps #floods? #glaciers? #impacts? #AGU24 (9/10)

PhD student Timmy Lui will take us to #Mars for his " #Segmentation of #dune crestlines using #convolutional #neural #networks" (EP51D-1378, hall B-C). Fr 8:30 am-12:20 pm. A challenging task with potential to reveal much about #Mars #climate! #AGU24 (7/10)

Kicking off Fr, PhD student Vittorio Colicci will present his MS work at MIT, "Examining the influence of early #tree #root geometry on #soil cohesion and anchoring strength using 3D-printed reconstructions" (EP51F-1439, hall B-C) Fr 8:30 am-12:20 pm #AGU24 (6/10)

Alternatively, undergrad Brian Amaro will talk about his "Automatic characterization of the size distribution of small #rocks on the #Moon and implications for orbiter-based extrapolations" (P44C-06, Liberty M at Marriott). Th 4:52-5:02 pm. #AGU24 (5/10)

Then former postdoc @agunn.bsky.social (now faculty at Monash) and recipient of #AGU24 's Luna Leopold award will deliver the Sharp lecture (Ballroom B). #Dunes galore on the horizon! Th 4-5:30 pm. (4/10)

Next: #Precambrian #Earth with PhD student @mcolinmarvin.bsky.social, with "Zircon microtextures: A record of Earth's earliest surface environments" (EP43F-03, 146 C). Th 2:30-2:40 pm. Tiny scratches pack much info on first ~90% of Earth's history! #AGU24 (3/10)

First stop: #Earth with PhD student Michael Hasson for " #Vegetation alters the migration trajectory of #meander bends" (EP41E-1245, hall B-C). Th 8:30 am-12:20 pm. Cool implications for river evolution in the #Paleozoic! #AGU24 (2/10)

#Rivers, #winds, #waves, and #impacts are all on the program for Stanford EPSP at #AGU24! Come along with us to explore #landscapes through #space (#Earth, #Moon, #Mars) and #time ( #Archean / #Hesperian to #future) All times EST. (1/10)

📢The recording of our workshop at #AGU24 is now live on YouTube! 🎥 Huge thanks to Justin Braaten for the fantastic collaboration! Watch here: youtu.be/JavlJrzcCDw Explore the Notebook: geemap.org/workshops/AG... #geospatial #opensource #EarthEngine #geemap

hi everyone!! posts here about geomorphology and climate. check out colin marvin's new paper on dune interactions: doi.org/10.1130/G512...