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Brian Romans

@clasticdetritus.bsky.social

2.2K followers 260 following 970 posts

Virginia Tech Geosciences professor (vtsedsystems.org) ⏐ sedimentology, (paleo)climate, tectonics, sedimentary basins, subsurface geology, geoeducation ⏐ listening and learning

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Brian Romans @clasticdetritus.bsky.social · 22d

in Copenhagen this week for the IODP Exp400 post-cruise science meeting and our hosts at GEUS (Geological Survey of Denmark and Greenland) led a day trip to Stevns Klint, a UNESCO World Heritage Site featuring a K-Pg boundary section ⚒️🧪

View of the latest Cretaceous and earliest Paleocene carbonate sedimentary rocks near Rødvig, Denmark

Examining the K-Pg boundary in carbonate sedimentary rocks near Rødvig, Denmark

Me pointing at the 'fish clay' layer, which is the expression of the K-Pg boundary in sedimentary rocks near Rødvig, Denmark

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Brian Romans @clasticdetritus.bsky.social · 7d

💥

Brian Romans @clasticdetritus.bsky.social · 8d

This better be giant, all-caps type in headlines on every news outlet in the country for days. This is our government literally declaring war on it's own citizens. This isn't nuanced or ambiguous, he is saying it very clearly.

But I have zero confidence in our national media to meet this moment.

Aaron Rupar @atrupar.com · 8d

Trump: "The ones that are run by radical left Democrats -- what they've done to San Francisco, Chicago, New York, Los Angeles. They're very unsafe places & we're gonna straighten them out one by one. This is gonna be a major part for some people in this room. That's a war too. It's war from within"

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Brian Romans @clasticdetritus.bsky.social · 10d

yea, that all makes sense ... thanks for articulating that

when an ice stream advances out to cont. shelf edge, leading to isostatic subsidence (and RSL rise), does the ice front 'lift off' the grounding zone? or, are those processes at different timescales?

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Brian Romans @clasticdetritus.bsky.social · 10d

I guess that is a key question ... is sed delivery to the slope primarily during glacial max (when grounding zone near/at shelf edge) or during early deglacial/retreat when meltwater is doing a lot of sed transport work ... and, as always, maybe both and it depends

Brian Romans @clasticdetritus.bsky.social · 10d

or, put another way, is the shelf-to-slope sediment delivery system is driven almost completely by sediment supply factors (which, in turn, have a bunch of drivers) and local SL stand is of little influence (?)

Brian Romans @clasticdetritus.bsky.social · 10d

we are mostly interested in the occurrence/timing of downslope (shelf edge to base-of-slope) sediment delivery as a function of the advance-retreat cycle –– e.g., although local SL is high during glacial max, the sed supply is sufficiently high to deliver sed to the lower slope

Brian Romans @clasticdetritus.bsky.social · 11d

maybe because the topography is high spatial resolution (but temporally static) whereas the atmospheric data is high resolution both spatially and temporally (?) ... most geologists (👋) likely don't know how to synthesize such info in a way that represents an overall (time-averaged?) behavior

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Brian Romans @clasticdetritus.bsky.social · 11d

My question for any ice sheet researchers/experts reading this is if you can point me to some other studies that get into these complexities in more detail. There's plenty about modern glacio-isostasy and SL, but I'm interested in past glacial maxima (LGM or older) and shelf-slope sedimentation. 3/3

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Brian Romans @clasticdetritus.bsky.social · 11d

... isostatic response to ice (and water) loading/unloading. The associated conceptual model showing the style and timing of sedimentation is a much more complex version of classic 'highstand' vs. 'lowstand' models for non-glaciated margins. 2/3

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Brian Romans @clasticdetritus.bsky.social · 11d

This summary figure from a 1990 paper by Boulton depicts the local/relative SL change (what I show in blue) as opposite to the global/eustatic change –– that is, a relative rise in SL during maximum ice sheet extent/size at that location when the global condition is lower SL, due to ... 1/3

Figure 30 from Boulton (1990) Geological Society London special publication showing conceptual model of sedimentation response to an ice stream during a full glacial cycle.

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Brian Romans @clasticdetritus.bsky.social · 11d

one of the great advantages of ditching most social media platforms and checking the few I'm still on only occasionally (a few times a week) is that I'm blissfully unaware of the discourse about discourse on social media

Brian Romans @clasticdetritus.bsky.social · 13d

I haven't lived in the Bay Area since 2011, so I'm definitely out of the loop

Brian Romans @clasticdetritus.bsky.social · 13d

oh wow, blast from the past ... I do love that beach

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Brian Romans @clasticdetritus.bsky.social · 14d

nice, thanks ... this is definitely relevant for later in the term in my Sed Basins course when we get into some geo/thermochron

Brian Romans @clasticdetritus.bsky.social · 17d

I've started reading @peterbrannen.bsky.social's "The Story of CO2 is the Story of Everything" and I'm going old school by underlining and jotting down notes in the margins

here are a couple of excerpts in the section introducing silicate weathering and the carbon cycle ⚒️📚

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Brian Romans @clasticdetritus.bsky.social · 18d

D is clearly the front-runner here ... but G has got Mexican food (which would be difficult for me to live without), southern U.S. soul food, BBQ, southwest U.S., Caribbean, and southern Spain

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Brian Romans @clasticdetritus.bsky.social · 18d

difficult choice between D and G

Brilliant Maps @brilliantmaps.bsky.social · 22d

For the rest of your life, you can only eat food from one of these regions. Which do you choose?

For more maps: brilliantmaps.beehiiv.com/s...

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Reposted by Brian Romans

Julia Carrie Wong @joolia.bsky.social · 18d

this exists it is called thinking

Matthew McConaughey says he wants a private LLM, fed only with his books, notes, journals, and aspirations, so he can ask it questions and get answers based solely on that information, without any outside influence.

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Brian Romans @clasticdetritus.bsky.social · 18d

iconic

Brian Romans @clasticdetritus.bsky.social · 19d

a fantastic four days at the IODP Exp400 science meeting at GEUS (Geological Survey of Denmark & Greenland) in Copenhagen –– didn't have much time to explore and sight-see, hope to come back one day

very excited about all the interesting science already coming out of this expedition, lots to do!

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Brian Romans @clasticdetritus.bsky.social · 21d

yes, the event ~65 million years ago that led to a mass extinction –– including some dinosaurs, but also lots of other species

Brian Romans @clasticdetritus.bsky.social · 22d

that last photo is me pointing at the 'Fish Clay', that thin layer of silty mud is the K-Pg event –– when the depositional system is biogenic carbonate material (coccolith chalk below and bryozoan mounds above), such a significant disruption to life and ecosystems is easy to see!

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Brian Romans @clasticdetritus.bsky.social · 22d

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Brian Romans @clasticdetritus.bsky.social · 24d

this should be getting non-stop red-siren coverage on NY Times, WaPo, CNN, NPR, and the rest ... instead they will all shrug it off or, worse, try to explain it away ... I have zero confidence in our media to meet the moment of this era

Brian Romans @clasticdetritus.bsky.social · 25d

not a great pic (is a bit grainy, I was zoomed in) but this is later that same day (Sept 13, 2023) when we got to watch the sunset and this iceberg that was hanging around for some days 🧊🌅

Sunset in Baffin Bay with an iceberg in the foreground, from the deck of the JOIDES Resolution drillship (Sept 13, 2023).