Lmst

Mid-Proterozoic Expansion Of Passive Margins And Reduction In Volcanic Outgassing Supported Marine Oxygenation And Eukaryogenesis
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https://doi.org/10.1016/j.epsl.2025.119683 <-- shared paper
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https://zenodo.org/records/17353904 <-- supplementary data
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#proterozoic #platetectonics #tectonics #deepcarboncycle #eukaryogenesis #evolutionoflife #life #evolution #geology #geologichistory #pangea #supercontinent #diversification #volcanic #offgassing #marine #thermodynamics #model #modeling #spatialanalysis #spatiotemporal #nuna #subduction #structuralgeology #CO2 #carbondioxide #climate #eukaryotic #BoringBillion #rodinia #oceanbasins #marinechemistry #outgassing #global #earth

#WeekendReading: Canfield et al., looking at some proxy records for continental weathering to see how it changed between the #Proterozoic and #Phanerozoic, and how it might have affected the #sea.
https://www.pnas.org/doi/10.1073/pnas.2507312122

Change in %Al over time in sedimentary rocks.

Interesting attempt to obtain direct samples of Earth's atmosphere from 815 million years ago, using bubbles trapped in halite (NaCl salt). Salt is a good host for this, because it doesn't react much with air ingredients. Also, because it's water soluble, it's relatively easy to spot if anything has happened to it since it formed. 🤓 #Geology #Atmosphere #Salt #Evaporites #Proterozoic #OpenAccess
https://pubs.geoscienceworld.org/gsa/geology/article/44/8/651/188284/Paradigm-shift-in-determining-Neoproterozoic

@KateShaw has made a new episode, featuring goblet-shaped Diskagma of the Paleoproterozoic, and Horodyskia of the Mesoproterozoic and Neoproterozoic.

https://strangeanimalspodcast.blubrry.net/2025/08/04/episode-444-diskagma-and-horodyskia/

#fossils
#preCambrian
#proterozoic
#Paleoproterozoic
#Mesoproterozoic
#Neoproterozoic
#Ediacaran

https://xkcd.com/3008

#xkcd #proterozoic #palaeontology

Boring Billion (Geological periods 🌍)

The Boring Billion, otherwise known as the Mid Proterozoic and Earth's Middle Ages, is an informal geological time period between 1.8 and 0.8 billion years ago during the middle Proterozoic eon spanning from the Statherian to the Tonian periods, characterized by more or less tectonic stability, climatic stasis and slo...

https://en.wikipedia.org/wiki/Boring_Billion

#BoringBillion #Proterozoic #Astrobiology #1995InScience #PlateTectonics #GeologicalPeriods

Volyn biota (Ecosystems 🏞️)

The Volyn biota are fossilized microorganisms found in rock samples from miarolitic cavities of igneous rocks collected in Zhytomyr Oblast, Ukraine. It is within the historical region of Volyn, hence the name of the find. Exceptionally well-preserved, they were dated to 1.5 Ga, within the "Boring Billion" period of the Proterozoic geological eon.

https://en.wikipedia.org/wiki/Volyn_biota

#VolynBiota #Volhynia #Ecosystems #Lithophiles #Proterozoic #ZhytomyrOblast

#DogWalkingGeology from yesterday.... Spud has found some garnet-tastic Moine metabasic tuffs(?) or maybe an intrusion. Each knobbly bit is a large garnet crystal, but alas they are never show external crystal faces, and are always stuffed with gazillions of quartz inclusions. Still, lovely to see! #Metamorphic #Garnet #Mull #Moine #Proterozoic 😊

A black and white collie dog stands on a sandy beach, at the top right of the photo. They are looking towards the camera over a reddish brown algae-covered rock outcrop in the foreground, with a very knobbly texture. On the sand, and on the rock, are some wisps of bright green seaweed.

A very productive hour spent learning about Earth's primary productivity (organic molecules produced) over time via a talk by Peter Crockford, Carleton University.

Fun fact: every carbon atom has likely be cycled through an organism ~100 times over the last 3+ billion years!

Crockford et al., The geologic history of primary productivity, Current Biology (2023), https://doi.org/10.1016/ j.cub.2023.09.040

#CarletonU #McGillUniversity #Photosynthesis #EarthSystemScience #Proterozoic #Geology

Figure 1 from Crockford et al, 2013. It shows estimates of primary productivity over time, along with the dominant type of organisms contributing to the production of organic molecules.

#Mafic enclave (?) in Rattlesnake Hill #Granite, #Massachusetts

This Devonian granite intrudes #Proterozoic Dedham Granite south of #Boston. It is younger than the nearby Blue Hill Granite Porphyry. The triangular area is rich in large crystals, possibly hornblende. The blue crystals at lower left may be #riebeckite, another amphibole. Riebeckite gives Quincy Granite and the #BlueHills Range their distinctive color. All on Avalon terrane, out of Gondwana. Acadian Orogeny was Devonian. My #photo

Above and upon #igneous #dikes

The feature sure looked like a #dike on #satellite view, and a ground check confirmed it. Probably a late #Triassic or early #Jurassic intrusion into #Proterozoic Dedham #Granite, as #Pangea rifted. At Black Rock #Beach, #Hingham, #Massachusetts, #NewEngland #geology USA.

Satellite view from #AppleMaps, #photo by me.

Satellite map of Black Rock Beach area, with the Atlantic Ocan at the top (north). Cars in image provide scale. A putative dike complex is visible as lineations near the image center.

A gray-blue mafic rock has intruded into the buff-toned (felsic) granite. Sunglasses at bottom for scale.

More #geotourism, this time in the lovely postglacial landscape of #Ontario, #Canada, specifically an island in #SandLake on the #RideauCanal. Always amazing to consider that around 15,000 years ago this spot would have been under at least 1000 metres of ice.

The rocks at this spot are a mixture of #Proterozoic metasediments of the Grenville Supergroup - basically billion year old sedimentary rocks that were well baked and deformed by a major mountain building event that pre-dates the formation of Appalachian Mountains (which formed 'only' 250 million years ago).

And everything is pretty much covered in lichen... makes close-up images less interesting unfortunately :-)

A grey rocky island in a lake rising steeply to around 20 metres above the lake surface. The island is covered in dark green conifer trees with some lone trees sticking out in prominent positions.

Mount Roraima is composed of Proterozoic age sandstone formed about 2 billion years ago - possibly making it the oldest place on Earth.

#science #sciencefacts #mountroraima #mtrorai #proterozoic #sandstone

A new year of science facts comes with a new design - hope you like it! And thanks to all of you who made these daily tidbits so popular.

An awesome present from Australia - a lump of Proterozoic banded ironstone from the Marra Mamba Iron Formation (Hamersley region, Pilbara Craton, WA) - 2.4 billion years old.
Layered haematite & chert are evidence of fluctuations in primordial ocean oxygenation. #precambrian #proterozoic #geology

Katie Maloney spoke about the 950 million year old algae fossils from the Wernecke Mountains, Yukon Territory, Canada. She's reconstructing the biosphere and the spread of eukaryotes at a time before shells or any other hard parts evolved.
#McGillUniversity #EarthSystemScience #FossilFriday #Proterozoic #Yukon

Fossilized algae from the Proterozoic (950 Ma) in the Wernecke Mountains. Photo from Katie Maloney.

We walked around #Cohasset, #Massachusetts #USA in the unusually warm (50 F, 10 C) “winter” weather here in #NewEngland. This is an (absurdly) prosperous #coastal community just south of #Boston. The walk included lovely views across coves and marshes (including #invasive Phragmites australis and #peat under #native #Spartina), as well as nice exposures of the > 600 Ma #Dedham #granite, the #pluton coring most of the #Avalon terrane in this area.
#photo #igneous #Proterozoic #geology #saltMarsh

View of sunlit Phragmites australis seed heads on a marsh edge in this square format color image. Golden, low winter light illuminates the seed head and marsh behind, with woods in the distance and a mostly clear blue sky with just streaks of clouds, blurred by the wide aperture used for this photo. My photo.

A view out onto Cohasset Cove at low tide, in a 2 wide to 1 high color image. A wall and tree in the right foreground are in shadow, above a small tidal creek that flows into the cove. In the near left, over a meter of peat has accumulated in the marsh, covered by spartina. There are buildings, boats, and a barrier island in the distance. My photo.

An eastern red cedar (Juniperus virginiana) grows from a crack in Dedham Granite in this 4 high to 5 wide rectangular crop monochrome image. The crack extends from the low left to bottom right corner, and it is hosting moss along with the tree. The small tree rises through the left center of the frame, with characteristic spiny branches and bristly needles. The Dedham Granite is light gray and coarse in texture. My photo.

Country rock in Dedham Granite. The fine-grained, medium gray rock on the left is probably a chunk of surrounding rock that was plucked into the Dedham pluton (coarse, light gray rock at right) during intrusion. A small tuft of grass is on the right side of this square image. My photo.

Animal survival strategies in Neoproterozoic ice worlds - Here we discuss the survival strategies and habitats of modern polar marine organisms in environments analogous to those that could have existed during Neoproterozoic glaciations. We discuss how, despite the apparent harshness of many ice covered, sub-zero, Antarctic marine habitats, animal life thrives on, in and under the ice. https://bit.ly/3jL72eL
#SnowballEarth #Proterozoic #Life

When was the first time life began to prey on each other? https://phys.org/news/2022-12-life-began-prey.html

A case for an active #eukaryotic marine #biosphere during the #Proterozoic era: Lisa Eckford-Soper et al. https://www.pnas.org/doi/abs/10.1073/pnas.2122042119

"We use a size- & trait-based ecosystem model to show that the #microfossil record is most compatible with an active #eukaryote #ecosystem conducting #osmotrophy, #photosynthesis, #phagotrophy. Marine #ecosystems 1,700-780 Ma were far more active, diverse than generally thought."

#proterozoic

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