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Brian Ricketts

@kiwigeolog.bsky.social
1.4K followers 677 following 441 posts

Sedimentology, geofluids, sedimentary basins, volcanoes, planets - website for eager Earth Sci students at www.geological-digressions.com 🇨🇦-🇳🇿

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Brian Ricketts @kiwigeolog.bsky.social · 06/10/2026
Mary Andrews (1852-1914) never gained academic degrees or elected a Fellow to any scientific society. But she pursued a love of geology at a time when women were generally discouraged from contributing any kind of scientific endeavour. ⚒️🧪 www.geological-digressions.com/mary-katheri...
geological-digressions.com
Mary Katherine Andrews (1852-1914)
Mary Andrews (1852-1914) never gained academic degrees or won Society medals. But her scientific contributions were no less impressive or significant than those of other geologists.
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Brian Ricketts @kiwigeolog.bsky.social · 22/09/2026
Catherine Raisin (1855-1945) was an expert on metamorphic rocks, an early proponent of optical mineralogy, & a vociferous & generous supporter of women’s education, student's rights, and fairness in employment for staff at Bedford College, London. www.geological-digressions.com/catherine-ra... ⚒️🧪
geological-digressions.com
Catherine Raisin (1855-1945)
Catherine Raisin was an expert on the mineralogy of metamorphic rocks, and a vociferous and generous supporter of women’s education
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Brian Ricketts @kiwigeolog.bsky.social · 19/09/2026
I’ve got a sore neck from installing underfloor insulation beneath a part of the house that has temporarily become accessible because of some maintenance. Bloody awful job. Ranks up there with blackberry removal for awful jobs around the property.
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Brian Ricketts @kiwigeolog.bsky.social · 29/08/2026
Ida Slater was one of the 1st British women to work as a geologist & paleontologist; 1900-1912. Like her colleagues she had to fight prejudice & scientific & academic systems that excluded women. Success was testament to their intelligence & courage www.geological-digressions.com/ida-lilian-s... ⚒️🧪
geological-digressions.com
Ida Lilian Slater (1881-1969)
Ida Slater was one of the first British women to work and publish as a geologist and notable paleontologist.
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Brian Ricketts @kiwigeolog.bsky.social · 25/08/2026
3-dimensional dunes formed on the incoming tide over the margin of an ebb-tidal delta platform, Raglan Harbour, NZ. The dunes were modified during the ebb tide - most of the ripples are also ebb tide bedforms. Such a nice day - and not too crowded! View to the north, across the tidal channel. ⚒️🧪🌊
3-dimensional dunes formed on the incoming tide over the margin of an ebb-tidal delta platform, Raglan Harbour, NZ. The dunes were modified during the ebb tide - most of the ripples are also ebb tide bedforms. Such a nice day - and not too crowded! View to the north, across the tidal channel.
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Brian Ricketts @kiwigeolog.bsky.social · 18/08/2026
A largish andesite boulder (~3 m wide) perched over gypsum-halite evaporites on a Chilean Altiplano salar. Probably sourced from an old landslide. Eocene volcanic edifice in the background ⚒️🧪
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Brian Ricketts @kiwigeolog.bsky.social · 31/07/2026
Brief post on the first Black American woman to earn a PhD in geosciences. She was also a teacher and staunch advocate for Black and women students. www.geological-digressions.com/marguerite-t...
geological-digressions.com
Marguerite Thomas Williams (1895-1991)
Marguerite Thomas Williams was a Black American geographer, geologist, teacher, and STEM advocate in the first half of the 20th C.
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Brian Ricketts @kiwigeolog.bsky.social · 16/07/2026
Nice crop of tangelos - soon be ready for family, friends, and the local food bank.
Nice crop of tangelos - soon be ready for family, friends, and the local food bank.
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Brian Ricketts @kiwigeolog.bsky.social · 04/07/2026
Brief post on Pioneering women in Earth Sci. Marie Stopes, a paleobotanist whose scientific work encompassed ancient & modern flora. Probably better know as a vociferous advocate for women's reproductive rights and eugenicist in post-WWI Britain. www.geological-digressions.com/marie-carmic... ⚒️🧪
geological-digressions.com
Marie Carmichael Stopes (1880-1958)
Marie Stopes was a paleobotanist whose scientific work encompassed ancient and modern flora. She was also a vociferous advocate for women
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Brian Ricketts @kiwigeolog.bsky.social · 20/06/2026
Exposure of old sand dunes. Wind, rain, and sea spray-sculpted sandstone, witness to the vagaries of weather. ⚒️🧪
Exposure of old sand dunes. Wind, rain, and sea spray-sculpted sandstone, witness to the vagaries of weather.
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Brian Ricketts @kiwigeolog.bsky.social · 14/06/2026
Wind & rain sculpted surface of lee-slope crossbedding in a dune abt 3 m thick. It was part of a Pleistocene coastal dune-barrier system that accumulated when sea levels were significantly lower. The modern expression of the barrier terminates at the entrance to Manukau Harbour, west Auckland 🧪⚒️🌊
Wind & rain sculpted surface of lee-slope crossbedding in a  dune abt 3 m thick.  It was part of a Pleistocene coastal dune-barrier system that accumulated when sea levels were significantly lower. The modern expression of the barrier terminates at the entrance to Manukau Harbour, west Auckland
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Brian Ricketts @kiwigeolog.bsky.social · 11/06/2026
Superb winter's day looking at Pleistocene dune deposits; lots of crossbeds, interdune peats, watertable iron pans, liesegang designs, and wind-rain-sea spray sculpted sandstone. Kariotahi, west Auckland 🧪⚒️
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Brian Ricketts @kiwigeolog.bsky.social · 27/05/2026
Anne Phillips (1803-1862), niece to William Smith (map of England fame) is an enigmatic 19th C figure in English geological science, discovered evidence for Malvern Hills structure that disproved the ideas of more famous gentlemen geologists. ⚒️🧪 www.geological-digressions.com/anne-phillip...
geological-digressions.com
Anne Phillips (1803-1862)
Anne Phillips was an accomplished field geologist who understood the importance of stratigraphic organization and rock provenance.
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Brian Ricketts @kiwigeolog.bsky.social · 04/05/2026
It's Fall in New Zealand. This mushroom growing from a branch cavity provides the perfect and fortuitous platform for a falling Maple leaf
It's Fall in New Zealand. This mushroom growing from a branch cavity provides the perfect and fortuitous platform for a falling Maple leaf
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Reposted by Brian Ricketts
Stephen Lokier @lokier.bsky.social · 08/04/2026
Today, Lesli Wood will present a webinar on deepwater fans & dynamic Caribbean sedimentation. We are also celebrating 6 years of #sedsonline with an exciting announcement!
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Brian Ricketts @kiwigeolog.bsky.social · 27/03/2026
Reba Masterson’s (1882 – 1969) reputation as the first female petroleum geologist is founded on her fierce independence and determination to succeed in a male-dominated profession. www.geological-digressions.com/reba-byrd-ma... Another entry in Pioneering women in Earth Sciences ⚒️🧪
Reba Masterson’s (1882 – 1969) reputation as the first female petroleum geologist is founded on her fierce independence and determination to succeed in a male-dominated profession. 
Another entry in Pioneering women in Earth Sciences
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Brian Ricketts @kiwigeolog.bsky.social · 25/03/2026
On a recent trip to Tasmania - MONA (Hobart)- the Museum of Old and New Art. The gallery is excavated in Triassic fluvial sandstone. It's one of the quirkiest galleries I've ever visited. The artistic emphasis is sex, death, & guts. An advertisement advises folk to "... Talk crap about the art."
On a recent trip to Tasmania - MONA (Hobart)- the Museum of Old and New Art. The gallery is excavated in Triassic fluvial sandstone. It's one of the quirkiest galleries I've ever visited. The artistic emphasis is sex, death, & guts. 

An advertisement advises folk to "... Talk crap about the art."
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Brian Ricketts @kiwigeolog.bsky.social · 09/03/2026
For International Women's Day and Women's History Month, here's the list of Earth science pioneers I've written about so far (compiled in approximate alphabetical order). Page link: www.geological-digressions.com/how-to-do-fi... ⚒️🧪🌊
For International Women's Day and Women's History Month, here's the list of Earth science pioneers I've written about so far (compiled in approximate alphabetical order). 
Page link:  https://www.geological-digressions.com/how-to-do-field-tasks/pioneering-women-in-earth-science/
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Brian Ricketts @kiwigeolog.bsky.social · 27/02/2026
Calcite-cemented coastal dunes (aeolianites) etched by wind, rain, and sea spray. The more-or-less vertical tracery formed originally as burrows (excavated by former dune-dwelling critters) and plant roots. Geo age uncertain. Sandy Cape, Western Australia. The head shape reminds me of Eeyore! ⚒️🧪
Calcite-cemented coastal dunes (aeolianites) etched by wind, rain, and sea spray. The more-or-less vertical tracery formed originally as burrows (excavated by former dune-dwelling critters) and plant roots. Geo age uncertain. Sandy Cape, Western Australia. The head shape reminds me of Eeyore!
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Brian Ricketts @kiwigeolog.bsky.social · 16/02/2026
Some tallish sunflowers - the one at the back is nearly 4 m. Also some quince nearly ready to pick. The tomatoes are climbing through the window. They all got a good soak during the last storm - 253 mm rain in 24 hours.
Some tallish sunflowers - the one at the back is nearly 4 m. Also some quince nearly ready to pick. The tomatoes are climbing through the window. They all got a good soak during the last storm - 253 mm rain in 24 hours.
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Brian Ricketts @kiwigeolog.bsky.social · 14/02/2026
Some of the nicest, rectangular fracture networks in pebbly mudstone - diamictite (age uncertain but probably middle to late Paleozoic). Friendly Beach, eastern Tasmania. A bit like a block of chocolate where each piece is filled with crunchy pebbles. ⚒️🧪
Some of the nicest, rectangular fracture networks in pebbly mudstone - diamictite (age uncertain but probably middle to late Paleozoic). Friendly Beach, eastern Tasmania. A bit like a block of chocolate where each piece is filled with crunchy pebbles.
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Brian Ricketts @kiwigeolog.bsky.social · 01/02/2026
The list so far of Pioneering Women in Earth Science at this point focused on 18th - early 20th C. In approx order of compilation. Most accounts are brief - but I list as many accessible references as possible. Lots still to write about ⚒️🧪🌊 www.geological-digressions.com/how-to-do-fi...
The list so far of Pioneering Women in Earth Science at this point focused on 18th - early 20th C. In approx order of compilation. Most accounts are brief - but I list as many accessible references as possible. Lots still to write about
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Brian Ricketts @kiwigeolog.bsky.social · 29/01/2026
My contribution to the discussion on SAND. I combine a photo of large dunes masquerading as small dunes, made of Martian sand in the Namibian dune field - oodles of sand but no beach. ⚒️🧪
My contribution to the discussion on SAND. I combine a photo of large dunes masquerading as small dunes, made of Martian sand in the Namibian dune field - oodles of sand but no beach.
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Brian Ricketts @kiwigeolog.bsky.social · 22/01/2026
A casual stroll along the beach. Shark Bay, Western Australia. Also where the Monkey Mia dolphins come in for a feed - usually accompanied by a couple of local pelicans looking for leftovers ⚒️🧪🌊
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Brian Ricketts @kiwigeolog.bsky.social · 18/01/2026
Limestone Pinnacles near Cervantes, Coral Coast, W Australia. Mostly shelly limestone, perhaps 2-3 million years old (age is uncertain). The karst landscape formed a few 10s of 1000s of years ago. Most <5m high. Temperatures in the mid 30s C in mid-November when we were there. ⚒️🧪
Limestone Pinnacles near Cervantes, Coral Coast, W Australia. Mostly shelly limestone, perhaps 2-3 million years old (age is uncertain). The karst landscape formed a few 10s of 1000s of years ago. Most <5m high. Temperatures in the mid 30s C in mid-November when we were there.
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Brian Ricketts @kiwigeolog.bsky.social · 17/01/2026
Detached beach ridge at the inactive margin of a small fan delta - the active braided part is on far side. An older dissected delta segment in the background. Large ice polygons across the delta surface. Ellesmere Island. About 600-800 m wide. ⚒️🧪🌊 www.geological-digressions.com/beach-microc...
Detached beach ridge at the inactive margin of a small fan delta - the active braided part is on far side. An older dissected delta segment in the background. Large ice polygons across the delta surface. Ellesmere Island. About 600-800 m wide.
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Brian Ricketts @kiwigeolog.bsky.social · 12/01/2026
An easy walk along sea cliffs of Cambrian-Silurian Tumblagooda Sandstone, ~ 450-400 million years old, S of Kalbarri, W Australia. Lots of crossbedding. Ancient river deposits at a time of zero terrestrial vegetation. ⚒️🧪
An easy walk along sea cliffs of Cambrian-Silurian Tumblagooda Sandstone, ~ 450-400 million years old, S of Kalbarri, W Australia. Lots of crossbedding. Ancient river deposits at a time of zero terrestrial vegetation.
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Brian Ricketts @kiwigeolog.bsky.social · 05/01/2026
Mary Somerville - the person for whom the word scientist was coined by William Whewell in his 1834. She was a polymath, an intellectual tour de force at a time when teaching women to read and write let alone think deeply was frowned upon or ignored ⚒️🧪🌊 www.geological-digressions.com/mary-somervi...
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Brian Ricketts @kiwigeolog.bsky.social · 19/12/2025
Goat I. northern Tasmania. Strongly foliated metamorphic rks. A haven for Small Blue Penguins, nightly raucous partying as they make their way onshore to their nests, with the tide - we had one under our bedroom window!⚒️🧪🌊
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Brian Ricketts @kiwigeolog.bsky.social · 13/12/2025
Lovely intertidal, northern Tasmanian serpulid worms encrusting a boulder (~60 cm wide). Each marine worm secretes its own tube out of calcium carbonate - tubes 2-3 mm diam. These critters can build extensive communities on rocky shores. ⚒️🧪🌊
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Brian Ricketts @kiwigeolog.bsky.social · 12/12/2025
Another great hike - Cradle Mountain N Tasmania. Dove Lake ringed by Mesoproterozoic greenschist ~1000-1600 million years old. The skinny horizontal layers are Permian ~250-298 m yrs so an age gap up to 1300 m yrs. Jagged peaks are dolerite that intruded the Permian deposits about 175 m yrs ago ⚒️🧪
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Brian Ricketts @kiwigeolog.bsky.social · 06/12/2025
Silurian felsic volcaniclastics, or if you prefer nice sea-worn bedrock, eastern Tasmania. Some of the most colourful lichen I've ever seen - this stuff is vivid. Can see it along much of NE Tasmania above high tide notably on the aptly-named Bay of Fires that we didn't get to but this will do ⚒️🧪
Silurian felsic volcaniclastics, or if you prefer some sea-worn bedrock, eastern Tasmania. Some of the most colourful lichen I've ever seen - this stuff is vivid. Can see it along much of NE Tasmania above high tide notably on the aptly-named Bay of Fires that we didn't get to but this will do
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Brian Ricketts @kiwigeolog.bsky.social · 05/12/2025
An excellent 12 km hike across Devonian syeno-granite - granodiorite intrusives, with a stop at Winglass Bay, Tasmania. 1 wallaby, 1 bird-eating snake (up a tree), lots of quartz-feldspar sand, and stiff 75 year-old knees ⚒️🧪
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Brian Ricketts @kiwigeolog.bsky.social · 04/12/2025
Hutt Lagoon W Aust on a dull day - pink hues are subdued ~14 km long & separated from the ocean by a sand barrier. Lake level is a few m bsl so sufficient hydraulic drive for sea water flow. It's hypersaline -halite precipitates along the shore. The colour caused by beta-carotene producing algae ⚒️🧪🌊
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Brian Ricketts @kiwigeolog.bsky.social · 27/11/2025
Shark Bay (W Aust) in Nov is warm- 30ish C but the rewards... Here, extensive sea grass meadows at Monkey Mia (the dark bands) feeding grounds for dugongs, rays, turtles, & nurseries for invertebrates, fish, all attracting sharks, dolphins, and seabirds incl pelicans & emu that wander the shore ⚒️🧪🌊
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Brian Ricketts @kiwigeolog.bsky.social · 23/11/2025
Lives cut short by whatever means always leave us wondering about lost potential (apart from any other kind of grief). Czechoslovak geologist & mineralogist Ludmila Slávíkova (1890–1943) died aged 53 at the hands of the most brutal regime imaginable ⚒️🧪🌊 www.geological-digressions.com/ludmila-slav...
geological-digressions.com
Ludmila Slavikova, (1890–1943)
Czechoslovak geologist and mineralogist Ludmila Slávíkova was scientist who died aged 53 at the hands of the most brutal regime imaginable.
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Brian Ricketts @kiwigeolog.bsky.social · 29/10/2025
Hannah Robertson, the little celebrated wife of David Robertson an eminent 19th C Scottish marine biologist, was accomplished in the science of modern seaweeds, conchology & foraminifera. Acknowledgements of her expertise were few #Pioneering #Women www.geological-digressions.com/hanna-robert... ⚒️🧪🌊
There are no photos of Hannah Robertson, so instead I add this one of modern NZ marine algae (seaweed) - the kind of thing that Hannah Robertson worked on. The seaweed garden hosts grazing gastropods, barnacles, mussels, encrusting bryozoa, and calcareous worm tubes (polychaetes)
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Brian Ricketts @kiwigeolog.bsky.social · 10/10/2025
Thin section images of glauconitic pellet sand dredged from about 300 m on Chatham Rise, an elongate marine platform extending 1400 km east of South I. NZ. It is underlain by continental crust - a submerged part of Zelandia continent. Includes barnacles, foraminifera & echinoderm plates, spines. ⚒️🧪🌊
Thin section images of glauconitic pellet sand dredged from about 300 m on Chatham Rise, an elongate marine platform extending 1400 km east of South I. NZ. It is underlain by continental crust - a submerged part of Zelandia continent. Includes echinoderm plates, spines, and foraminifera.
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Brian Ricketts @kiwigeolog.bsky.social · 06/10/2025
Triassic rocks (grey cliffs = sandstone + diabase) thrust over Early-Mid Eocene sandstone (foreground) along Mokka Fiord, Axel Heiberg I. (next door to Ellesmere I, N Canada). The thrust itself (at base of slope) may be through Carboniferous-Permian evaporites (mostly covered by scree). ⚒️🧪
Triassic rocks (grey cliffs = sandstone + diabase) thrust over Early-Mid Eocene sandstone (foreground) along Mokka Fiord, Axel Heiberg I. (next door to Ellesmere I, N Canada). The thrust itself (at base of slope) may be through Carboniferous-Permian evaporites (mostly covered by scree).
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Brian Ricketts @kiwigeolog.bsky.social · 29/09/2025
Some delicate actively growing stalactites from Ruakuri Caves, formed in Oligocene limestones. Skinny varieties are probably few decades old; the larger a few centuries. Ruakuri is the Maori name for Two Dogs - refers to early Polynesian canines brought to NZ. On a visit w a couple of grandkids ⚒️🧪
Some delicate actively growing stalactites from Ruakuri Caves, formed in Oligocene limestones. Skinny varieties are probably few decades old; the larger a few centuries. Ruakuri is the Maori name for Two Dogs - refers to early Polynesian canines brought to NZ. On a visit w a couple of grandkids
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Brian Ricketts @kiwigeolog.bsky.social · 28/09/2025
Front-yard spring! A cascade of colour, bird-song, and the odour of dung-spreading from nearby farms. ⚒️🧪😁
Front-yard spring! A cascade of colour, bird-song, and the odour of dung-spreading from nearby farms.
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Brian Ricketts @kiwigeolog.bsky.social · 22/09/2025
Claudine Picardet's (1735-1820) translation of texts for scientists like Karl Scheele, Abraham Werner, Richard Kirwan (phlogiston) & maybe Lavoisier. She enabled and participated in the dissemination of 18th-19th C science to a broad audience. ⚒️🧪 www.geological-digressions.com/claudine-pic...
geological-digressions.com
Claudine Picardet (1735-1820)
Claudine Picardet's (1735-1820) translation of science texts texts enabled the dissemination of 18th-19th C science to a broad audience.
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Brian Ricketts @kiwigeolog.bsky.social · 15/09/2025
Weathering patterns in basalt (a boulder lodged in beach sand) where oxidation of iron-bearing minerals (mainly amphiboles and pyroxenes) was controlled by earlier formed orthogonal joints. The dark grey bits are remnant non-altered basalt. Karioi Mt. Raglan, west coast NZ ⚒️🧪
Weathering patterns in basalt (a boulder lodged in beach sand) where oxidation of iron-bearing minerals (amphiboles and pyroxenes) was controlled by earlier formed orthogonal joints. The dark grey bits are remnant non-altered basalt. Karioi Mt. Raglan, west coast NZ
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Reposted by Brian Ricketts
authodizer @doktrock.bsky.social · 10/09/2025
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Brian Ricketts @kiwigeolog.bsky.social · 08/09/2025
A post I’ve been putting together for 2 years - the Etymology of Earth Sci Words. So far about 500 terms - the initial goal before clicking the ‘Publish’ tab www.geological-digressions.com/etymology-of... There are >1,000,000 words in the English language So my 500 words is a paltry sample. ⚒️🧪🌊
geological-digressions.com
Etymology of Earth science words and phrases
The origins of words, prefixes, suffixes, abbreviations, names, acronyms, and terms commonly used in Earth sciences.
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Brian Ricketts @kiwigeolog.bsky.social · 04/09/2025
I've been reluctant to post the 'Glossary of planetary geology' in my website, to the Astro & #planetsci feeds - because I'm an interloper in those fields, an Earth-bound geologist The rationale - I'm fascinated by it all There are 500 entries 🔭 ⚒️ www.geological-digressions.com/glossary-of-...
geological-digressions.com
Glossary of planetary geology
Glossary of planetary geology, the Solar System, moons, asteroids, comets, meteorites, exploration, and related terminology
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Brian Ricketts @kiwigeolog.bsky.social · 03/09/2025
The 2nd post - Expt Results. The expt is a good eg. of the sophistication now possible with physical, stratigraphic and sedimentologic modeling. Chris Paola, one of the creators of the XES facility, generously provided copies of the images used here.⚒️🧪 www.geological-digressions.com/experimental...
geological-digressions.com
Experimental sequence stratigraphy:  model results
Description of an experiment (Martin et al.,.2009) that evaluates geometry & chronostratigraphic significance of sequence stratigraphic surfaces in a scale-independent model where only base level chan...
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Brian Ricketts @kiwigeolog.bsky.social · 03/09/2025
More on geological modeling for students, 2 posts on a scale-independent stratigraphy experiment using the XES facility at St. Anthony Falls Lab, Minnesota U- the 1st model to incorporate variable subsidence 1st post - methods & boundary conditions ⚒️🧪 www.geological-digressions.com/experimental...
geological-digressions.com
Experimental sequence stratigraphy:  model attributes
This post describes the experiment methods and boundary conditions of a scale-independent, experimental stratigraphic model
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Brian Ricketts @kiwigeolog.bsky.social · 01/09/2025
Elizabeth Philpot was an important participant in the late 18th and 19th C development of paleontology and geology, a collaborator with Mary Anning, Louis Agassiz, Henry De la Beche, William Buckland, and others. The fish was one of her discoveries ⚒️🧪🌊 www.geological-digressions.com/elizabeth-ph...
Elizabeth Philpot was an important participant in the late 18th and 19th C development of paleontology and geology, a collaborator with Mary Anning, Louis Agassiz, Henry De la Beche, William Buckland, and others. The fish was one of her discoveries
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Brian Ricketts @kiwigeolog.bsky.social · 13/08/2025
Sponge spicules, composed of silica, in thin section. The ornate end structures are used to attach one spicule to another to form an internal skeleton that is flexible enough to sway and bend in flowing water (from Three Kings Islands seafloor, northernmost NZ). ⚒️🧪🌊
Sponge spicules, composed of silica, in thin section. The ornate end structures are used to attach one spicule to another to form an internal skeleton that is flexible enough to sway and bend in flowing water (from Three Kings Islands seafloor, northernmost NZ).
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