Hematite ooids, too! ⚒️
Welcome back to #FossilFriday
Here is a beautiful polished section of the Stromatolite Collenia undosa. This comes from the Precambrian (Paleoproterozoic) Biwabik Iron Formation in Minnesota. It is commonly referred to as Mary Ellen Jasper. This trace fossil is 2.2-2.4 billion years old!
Here is a beautiful polished section of the Stromatolite Collenia undosa. This comes from the Precambrian (Paleoproterozoic) Biwabik Iron Formation in Minnesota. It is commonly referred to as Mary Ellen Jasper. This trace fossil is 2.2-2.4 billion years old!
June 14, 2025 at 10:38 AM
Hematite ooids, too! ⚒️
I always said if I hadn't gone into volcanology, I would've studied ooids. They form in warm, shallow waters...and who wouldn't want to snorkel to do their research?
However, most people didn't think Utah when they think ooids. This is so cool!
However, most people didn't think Utah when they think ooids. This is so cool!
Oolitic sand from the Great Salt Lake, Utah. The ooids are believed to have formed around a nucleus composed of brine shrimp fecal pellets. Sample 0061.
#sand #arenophile #ultramacrophotography
#sand #arenophile #ultramacrophotography
January 25, 2025 at 6:17 PM
I always said if I hadn't gone into volcanology, I would've studied ooids. They form in warm, shallow waters...and who wouldn't want to snorkel to do their research?
However, most people didn't think Utah when they think ooids. This is so cool!
However, most people didn't think Utah when they think ooids. This is so cool!
Man, those look so much like ooids to me. 🧪⚒️
March 27, 2025 at 3:19 PM
Man, those look so much like ooids to me. 🧪⚒️
Lacustrine ooids and coated grains (mainly ostracods) from the Eocene Green River Formation, UT (USA). #ThinSectionThursday
March 20, 2025 at 12:57 PM
Lacustrine ooids and coated grains (mainly ostracods) from the Eocene Green River Formation, UT (USA). #ThinSectionThursday
Really cool ooids in Snowslip Fm seen today in a cobble at Grinnell Glacier. Field of view is about 1cm. ⚒️
July 16, 2026 at 1:00 AM
Really cool ooids in Snowslip Fm seen today in a cobble at Grinnell Glacier. Field of view is about 1cm. ⚒️
Even a town like #Amstelveen hosts some impressive #UrbanGeology: four times pretty different #limestone. #Goniatite, #ooids, #gastropod (#nerinea) and #hardgrounds with #bioturbation. #geology #rocks ⚒️🧪
April 19, 2025 at 4:50 PM
Even a town like #Amstelveen hosts some impressive #UrbanGeology: four times pretty different #limestone. #Goniatite, #ooids, #gastropod (#nerinea) and #hardgrounds with #bioturbation. #geology #rocks ⚒️🧪
Giant ooids (pisolites) in the Beck Springs Formation of southern Death Valley. ⚒️
March 11, 2025 at 4:20 AM
Giant ooids (pisolites) in the Beck Springs Formation of southern Death Valley. ⚒️
More photos from the German #triassic #stromatolite quarry. See alt text for deets. #geology #paleontology
October 4, 2025 at 10:26 AM
More photos from the German #triassic #stromatolite quarry. See alt text for deets. #geology #paleontology
An important organic carbon proxy for ancient oceans:
"direct proxy for past DOC signatures using co-precipitated organic carbon in iron ooids..apply this to 26 marine iron ooid-containing formations deposited over the past 1,650 million years"
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #Geology
"direct proxy for past DOC signatures using co-precipitated organic carbon in iron ooids..apply this to 26 marine iron ooid-containing formations deposited over the past 1,650 million years"
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #Geology
August 16, 2025 at 9:24 PM
An important organic carbon proxy for ancient oceans:
"direct proxy for past DOC signatures using co-precipitated organic carbon in iron ooids..apply this to 26 marine iron ooid-containing formations deposited over the past 1,650 million years"
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #Geology
"direct proxy for past DOC signatures using co-precipitated organic carbon in iron ooids..apply this to 26 marine iron ooid-containing formations deposited over the past 1,650 million years"
www.nature.com/articles/s41...
🧪 ⚒️ #Paleobio #Geology
Late entry for #ThinSectionThursday: An photomicrograph of an ooid grainstone from the Jurassic Smackover Formation of Louisiana, USA. This pretty thin section is from our teaching collection. 🧪⚒️
November 22, 2024 at 12:35 AM
Late entry for #ThinSectionThursday: An photomicrograph of an ooid grainstone from the Jurassic Smackover Formation of Louisiana, USA. This pretty thin section is from our teaching collection. 🧪⚒️
A chondrite meteorite. The little circles are chondrules, rock vapor condensate grains - like space ooids; the oldest objects in our solar system. Chondrites are cosmic dust bunnies, as the chondrules glommed onto each other via static cling.
#spaceooids
⚒️
#spaceooids
⚒️
January 16, 2024 at 2:33 PM
A chondrite meteorite. The little circles are chondrules, rock vapor condensate grains - like space ooids; the oldest objects in our solar system. Chondrites are cosmic dust bunnies, as the chondrules glommed onto each other via static cling.
#spaceooids
⚒️
#spaceooids
⚒️
And for ‚proper‘ science: published three co-authored papers in 2025 about ooid formation, belemnite phylogeochemistry, and cameral deposit formation of orthoceratoid cephalopods. 🧪
link.springer.com/article/10.1...
bg.copernicus.org/articles/22/...
onlinelibrary.wiley.com/doi/full/10....
link.springer.com/article/10.1...
bg.copernicus.org/articles/22/...
onlinelibrary.wiley.com/doi/full/10....
January 1, 2026 at 6:50 PM
And for ‚proper‘ science: published three co-authored papers in 2025 about ooid formation, belemnite phylogeochemistry, and cameral deposit formation of orthoceratoid cephalopods. 🧪
link.springer.com/article/10.1...
bg.copernicus.org/articles/22/...
onlinelibrary.wiley.com/doi/full/10....
link.springer.com/article/10.1...
bg.copernicus.org/articles/22/...
onlinelibrary.wiley.com/doi/full/10....
link.springer.com/article/10.1...
New paper led by Phyllis Mono, and with a very small contribution by myself, about the formation and geochemistry of giant ooids from the Lower Triassic of Germany, #geology #sedimentology #geochemistry
New paper led by Phyllis Mono, and with a very small contribution by myself, about the formation and geochemistry of giant ooids from the Lower Triassic of Germany, #geology #sedimentology #geochemistry
Palaeoenvironmental implications and genesis of lacustrine Lower Triassic giant ooids - Facies
The sedimentary environment and mechanisms of formation of giant ooids (> 2 mm) are not well understood. Here, we use petrographical, mineralogical and geochemical data of giant ooids from the Lower T...
link.springer.com
January 15, 2025 at 6:20 PM
link.springer.com/article/10.1...
New paper led by Phyllis Mono, and with a very small contribution by myself, about the formation and geochemistry of giant ooids from the Lower Triassic of Germany, #geology #sedimentology #geochemistry
New paper led by Phyllis Mono, and with a very small contribution by myself, about the formation and geochemistry of giant ooids from the Lower Triassic of Germany, #geology #sedimentology #geochemistry
My contribution to the sand discourse is that a lot of the most stereotypical white sand beaches have carbonate sand, including my favorite kind of sand, ooids, but more commonly broken down skeletal carbonate.
January 29, 2026 at 2:51 AM
My contribution to the sand discourse is that a lot of the most stereotypical white sand beaches have carbonate sand, including my favorite kind of sand, ooids, but more commonly broken down skeletal carbonate.
Oolitic sand from the Great Salt Lake, Utah. The ooids are believed to have formed around a nucleus composed of brine shrimp fecal pellets. Sample 0061.
#sand #arenophile #ultramacrophotography
#sand #arenophile #ultramacrophotography
January 24, 2025 at 8:51 PM
Oolitic sand from the Great Salt Lake, Utah. The ooids are believed to have formed around a nucleus composed of brine shrimp fecal pellets. Sample 0061.
#sand #arenophile #ultramacrophotography
#sand #arenophile #ultramacrophotography
Many of the alkaline headstones, cornerstones and window ledges etc in East Anglian churches are made from oolitic limestone. Made up of ooids, which are grains of sand etc surrounded by layers of calcite deposition. Popular with stonemasons as it can be cut in any direction.
December 6, 2025 at 11:30 AM
Many of the alkaline headstones, cornerstones and window ledges etc in East Anglian churches are made from oolitic limestone. Made up of ooids, which are grains of sand etc surrounded by layers of calcite deposition. Popular with stonemasons as it can be cut in any direction.
LMAO = limestone mostly aragonitic ooids
TTYL = teeny tiny yearly laminae
TTYL = teeny tiny yearly laminae
November 13, 2024 at 12:52 AM
LMAO = limestone mostly aragonitic ooids
TTYL = teeny tiny yearly laminae
TTYL = teeny tiny yearly laminae
Pisolitas / Pisolites
Calcium carbonate ooids.
Sistema Pool Tunich
Quintana Roo, México.
Calcium carbonate ooids.
Sistema Pool Tunich
Quintana Roo, México.
November 30, 2024 at 7:02 AM
Pisolitas / Pisolites
Calcium carbonate ooids.
Sistema Pool Tunich
Quintana Roo, México.
Calcium carbonate ooids.
Sistema Pool Tunich
Quintana Roo, México.
I am a geologist who worked the GOM and this needed 100% more discussion of ooids and Smackover 😂
January 27, 2025 at 12:09 AM
I am a geologist who worked the GOM and this needed 100% more discussion of ooids and Smackover 😂
#gsaconnects2025 people, go check out some cool posters and talks this afternoon! Gabriel and Wilson both have cool posters incorporatibg machine learning with forams or ooids... I'll also be giving my talk about ooids and acidification this afternoon! @txgeosciences.bsky.social
October 20, 2025 at 6:13 PM
#gsaconnects2025 people, go check out some cool posters and talks this afternoon! Gabriel and Wilson both have cool posters incorporatibg machine learning with forams or ooids... I'll also be giving my talk about ooids and acidification this afternoon! @txgeosciences.bsky.social
Nature research paper: The geologic history of marine dissolved organic carbon from iron oxides
go.nature.com/3HaTbdN
go.nature.com/3HaTbdN
The geologic history of marine dissolved organic carbon from iron oxides - Nature
A direct proxy for past dissolved organic carbon signatures using co-precipitated organic carbon in iron ooids enables reconstruction of marine dissolved organic carbon signals dating back to the Palaeoproterozoic.
go.nature.com
August 19, 2025 at 10:36 AM
Nature research paper: The geologic history of marine dissolved organic carbon from iron oxides
go.nature.com/3HaTbdN
go.nature.com/3HaTbdN
The existence of ooids in HW big crafting/gathering was crucial to Boreal’s backstory
October 30, 2024 at 12:40 PM
The existence of ooids in HW big crafting/gathering was crucial to Boreal’s backstory
The giant ooids are my FAVORITE thing in Death Valley. Shoutout to Stan Awramik for running that trip annually for the first year geo grads. 😎
We traced the source of the giant ooid float in the Ibex Hills up to its source outcrop today: my first time seeing these primary structures (precipitated grains) in outcrop. ⚒️
March 11, 2025 at 4:26 PM
The giant ooids are my FAVORITE thing in Death Valley. Shoutout to Stan Awramik for running that trip annually for the first year geo grads. 😎
🚨 Paper alert! 🚨 After >1 year in review and six (6!) reviewers, I'm thrilled that this paper is finally out! Here, we provide the first data-based record of marine dissolved organic carbon in the geologic past.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
The geologic history of marine dissolved organic carbon from iron oxides - Nature
A direct proxy for past dissolved organic carbon signatures using co-precipitated organic carbon in iron ooids enables reconstruction of marine dissolved organic carbon signals dating back to the Pala...
www.nature.com
August 13, 2025 at 4:11 PM
🚨 Paper alert! 🚨 After >1 year in review and six (6!) reviewers, I'm thrilled that this paper is finally out! Here, we provide the first data-based record of marine dissolved organic carbon in the geologic past.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
The geologic history of marine dissolved organic carbon from iron oxides www.nature.com/articles/s41... #jcampubs 🌊
The geologic history of marine dissolved organic carbon from iron oxides - Nature
A direct proxy for past dissolved organic carbon signatures using co-precipitated organic carbon in iron ooids enables reconstruction of marine dissolved organic carbon signals dating back to the Pala...
www.nature.com
August 14, 2025 at 1:33 PM
The geologic history of marine dissolved organic carbon from iron oxides www.nature.com/articles/s41... #jcampubs 🌊