Marie-Claude Williamson

A thinsection imaged in cross-polarized light. Brightly colored pyroxene and olivine grains surround gray laminated plagioclase feldspar. field of view ~1mm. Sample 12005.

A magnesium-rich basalt retrieved by the Apollo 12 mission from the Moon. brightly coloured pyroxene and olivine surround grey plagioclase in cross-polars.

This photo was taken in 2003 from a travelling collection of thin sections sponsored by NASA […]

[Original post on fosstodon.org]

T.S. Thursday!
Large rounded grains of garnet surrounded by masses of muscovite mica and biotite mica. Also found are small, brown oval-shaped grains of tourmaline. By Larry Tuttle, U Maine Farmington. Send images and short caption to akoziol1 at udayton dot edu. #thinsectionthursday

Microscope photo of a slice of rock with white light shining through it. The rock is composed of a polygonal mosaic of mostly white crystal grains, light brown crystal grains, black crystal grains with a white crystal in the centre, and dark brown organic matter. A red scale bar shows the image is about 0.5 mm across our 500 microns.

Microscope photo of a slice of rock with cross polarised light shining through it. The rock is composed of a polygonal mosaic of mostly grey crystal grains, light brown-grey crystal grains, black crystal grains with a bright blue crystal in the centre, long thin orange grading to pink crystal grains, and dark brown organic matter. A red scale bar shows the image is about 0.5 mm across our 500 microns. The image has been rotated approx 45 degrees anti clockwise.

A 1.4 Ga organic rich mudstone from Australia that has low-grade contact metamorphism. Black blobs with crystal cores are thucolites, brown square is a fragment of microfossil that has been partially mineralised. More deets in alt text. #ThinSectionThursday #Geology #paleontology ⚒️🧪🔬

⚒️ - a bit early for #ThinSectionThursday but what the hell

An abstract image of a black sand beach (in the middle) with incoming waves at the top, and a yellow river at the bottom. The waves come over the beach and merge with the yellow river at the bottom right. There is a dry triangle of sand which looks brown in the middle.

Back to #Iceland photos from my recent trip. And here's another view of the marvellous yellow river estuary where it meets the sea at a black sand beach.

#DronePhotography #DJIMavic3Pro

🫧 Our scientists recently found ice in Antarctica that’s 6 million years old, trapped ancient air inside. These "time capsules" offer a rare peek into Earth’s past atmosphere and how our planet has changed.

📲Pop into the research at @iflscience.com: go.whoi.edu/ifl-ice

HiPOD: Colorful Bedrock in the Central Uplift of an Impact Crater

This bedrock has greater compositional diversity than the surface layers, because they are from greater depths, older, jumbled, and altered, and very diverse.

https://uahirise.org/hipod/ESP_045519_1730
#Mars #science #NASA

Image description: An audience watching a screen in a large hall. With text reading:" GeoCinema at the EGU26 General Assembly, Applications are now open! Submit your short film NOW! 5 December 2025."

#GeoCinema is back for #EGU26!

Whether you have filmed fantastic spectacles in the field or produced an educational feature on the Earth, planetary, or space sciences - it's time to submit your short film 🎞️!
📅Submission deadline: 5 December 2025
👀 Application details: egu.eu/13NFE9

🌋 Meet the Pioneer of 4K Volcano Livestreams: Ryan Logtenberg 🏔

Documenting the raw power of volcanoes isn't just his passion, it's his life's mission. ❤🔥

Read more about his work:

Get to know the IAVCEI Commission of Cities and Volcanoes (CaV) 🌋

CaV links the volcanology community with emergency managers, fostering the exchange of ideas and experiences among “volcano cities”, and promoting multi-disciplinary research and actions.

More about: citiesonvolcanoes.wordpress.com

#Earthquakes at #MountEtna reveal magma ascent from deep to shallow crust 🌋 — variations in #bvalue track magma movement through the volcano’s plumbing system.

Check out our new study in #ScienceAdvances

www.science.org/doi/10.1126/...

@science.org

More from our Etna studies below!

A great day at Dominica’s Boiling Lake, a hydrothermal wonder known for its bubbling surface and shifting activity, which we are closely monitoring.

Some of the ROTTnROCK team are currently in Dominica 🇩🇲 🌋 looking at, well, hydrothermal alteration of course!
@magmatroll.bsky.social
@trwalter.bsky.social
@arianeloisel.bsky.social

Color image of an almost-full moon. Nov. 5, 2025

Too cloudy for the full moon tonight, but here's last night's almost-full moon. If I didn't have a telescope, I'd never appreciate the color differences due to the different mineral compositions. 🧪

Some green thick column rocks against a black pebble beach with a small wave receding over a green rock on the beach. Behind is a pointy mountain with a little snow on the peak. Grey bright skies above.

Always nice to find some interesting new geology to photograph. Thanks to @andybeavisphoto.bsky.social for pointing me in the right direction!

#Iceland

🌋Did you know that there's more volcanic activity under the waves than on land?

Find out how underwater explosions impact our planet at the WHOI Ocean Learning Hub, a free resource that's perfect for educators, students, and the ocean-curious:
go.whoi.edu/volcano

📸 via ROV Jason 2009 © #WHOI

Illustration showing the giant sauropod dinosaur, Alamosaurus, in southern North America as the asteroid impact that caused the Cretaceous-Paleocene impact hits the Earth

Excited to share the results of collaborative research in the San Juan Basin in New Mexico published today in @science.org that provides new age constraints for the Naashobito dinosaurs from New Mexico, like the giant sauropod, Alamosaurus: www.science.org/doi/10.1126/...

Fieldwork at Iceland’s geysers — we captured Strokkur’s eruption dynamics as polar lights lit up the sky. What a scenery! Grateful for the great collaboration with Corrado Cimarelli and the LMU team, Sasha Kostinskiy and the group from Czechia, and our team from GFZ Potsdam.

Palagonitised lapilli tuffs from subglacial volcano Cracked Mountain 🌋🇨🇦 line up for physical property measurements in Strasbourg! Will their properties vary as a function of distance from the dyke? 🧐
@alteringrocks.bsky.social

#MolluscMonday Sectioned nerineoidean gastropod from a limestone paving slab at the British Museum, London.

The latest eruption of Kilauea is underway, and she's shootin' sideways this time around!

USGS live stream: www.youtube.com/watch?v=Bqmp...

A tall waterfall falls between vertical brown basalt colum cliffs at the top of the photo, with a shallow fall surrounded by stones below.

Not far from the canyon pictured in my last posting is this lovely waterfall over the basalt columns - Stuðlafoss.

#Iceland April 2023

In the foreground are the tops of two tall basalt columns - roughly hexagonal. below is a green river and on the other side are some short basalt columns at the foot of a tall cliff made up of many grey and slightly orange columns.

Looking down over the top of some vertical basalt columns into the canyon at Stuðlagil #Iceland in April 2023.

#Geology #GeologyRocks #BasatlPorn

A curious Arctic Fox pup checks out a nature photographer

Image cutout shows a cliff near the caldera of Arsia Mons on Mars. There is evidence of an ancient landslide of material on the slope of the cliff. There are numerous small impact craters on the landslide material that curves at one point. The scene is less than 5 km, 3 miles, across. (NASA/JPL-Caltech/University of Arizona)

HiPOD: A Landslide on Arsia Mons

Continuing a landslide theme, this observation captures terrain right at the edge of the caldera of Arsia Mons. Arsia Mons and two other volcanoes form what is known as the Tharsis Montes.

uahirise.org/hipod/ESP_07...
NASA/JPL-Caltech/University of Arizona
#Mars

Almost 50 years since PhD field work here - east side of Tukarak, Belcher Islands, Hudson Bay. Paleoproterozoic carbonates, Holocene raised beaches. Glorious rocks and landscapes. Tent site on island slightly left centre - the small white dot. Weather was generally crap, but on days like this...

Almost 50 years since PhD field work here - east side of Tukarak, Belcher Islands, Hudson Bay. Paleoproterozoic carbonates, Holocene raised beaches. Glorious rocks and landscapes. Tent site on island slightly left centre - the small white dot. Weather was generally crap, but on days like this... ⚒️🧪🌊

Social card. Background image is a stock photo of a small island with trees on water. The FACETS logo is overlaid. Text reads: Climate change and the Canadian marine conservation framework.

Canada has committed to protecting 30% of its marine areas by 2030. A FACETS collection provides policy-relevant insights to support this goal, addressing climate resilience in conservation planning. Discover the research ▶️ ow.ly/enVz50UYFpy

Mindat.org Mindat.org is the world's leading website about minerals and where they come from.

American Mineralogist:
Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research
Jolyon Ralph, et al.
doi.org/10.2138/am-2...
The aim is for users to be aware of the characteristics of the records in the database and better plan their usage in research.

Very large clear rectangular cut gem on a frosted plinth in front of a grey background. At the Royal Ontario Museum.

Guess the Gem time!! What mineral do you think this is? Hint: there’s lithium in there.
#GuessTheGem #GeoscienceBluesky ⚒️🧪💎

The mylonites I am looking at right now are not rocks, they are paintings... and - oh! It's #ThinSectionThursday

Mylonitic granite, CPL
FOV about 3 cm

#geology #tectonics #structuralgeology #mylonite #quartz #feldspar #granite #rheology