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!⚒️🧪🌊

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. ⚒️🧪🌊

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 ⚒️🧪

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 ⚒️🧪

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 ⚒️🧪

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 ⚒️🧪🌊

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 ⚒️🧪🌊

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...

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... ⚒️🧪🌊

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. ⚒️🧪🌊

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). ⚒️🧪

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 ⚒️🧪

Front-yard spring! A cascade of colour, bird-song, and the odour of dung-spreading from nearby farms. ⚒️🧪😁

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...

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 ⚒️🧪

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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. ⚒️🧪🌊

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-...

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...

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...

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...

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). ⚒️🧪🌊

Here's a nice Oligocene temperate water limestone photomicrograph from NZ, in PPL, with a glauconite-filled benthic foram, lots of bryozoa, some barnacle plates, echinoderm spines & plates, & the odd bivalve or gastropod fragment, all set in drusy calcite cement. Bar scale is 200 microns. ⚒️🧪🌊

Rocky intertidal life: a tangled web of calcareous serpulid worms (Pomatoceros) draped by the branched brown alga Xiphophora(?) A couple of snails nestling in crevasses (Cominella I think - top-bottom centre), a couple of grazing Paratrophon (left), and lots of small barnacles. Coromandel, NZ ⚒️🧪🌊

Another Pioneering Woman in Earth Science. Charlotte Murchison was an active collaborator and the intellectual equal and force behind her husband Roderick's scientific success. Also a friend of Mary Anning. www.geological-digressions.com/charlotte-mu... ⚒️🧪

Very nice climbing ripples from Gale crater - 305 million km away. Left: Out of phase (type 2) in lower half, In-phase (P) in upper section indicate a change in flow and proportions of suspended sediment load. Right: Type 2 variety. Arrows = flow directions. Credits NASA/JPL-Caltech/MSSS ⚒️🧪

A look at the sedimentary rocks on Mars that require flowing fluids. Focuses on bedload transport (of loose sediment) to form crossbeds - recognition of these structures provides clues to the former presence of fluids, particularly water. www.geological-digressions.com/evidence-for... ⚒️🧪

The recognition of lithified sediment has fundamental implications for Mars ancient history - the processes require aqueous chemical reactions. Here's a brief account of the criteria used to identify these rocks www.geological-digressions.com/evidence-for... ⚒️🧪

Shore-lead through gypsum-halite crusts on an Atacama - Altiplano salar, northern Chile. Snow in the foreground. Eocene volcanic cone at back. Early summer - the flamingos arrived soon after this was taken. About 4000 m altitude. UV index about 50% higher than at sea level. ⚒️🧪

Boulder pocket beaches between rocky headlands. Most of the larger clasts are moved only during Pacific storms. All volcanic, mostly andesite, dacite and rhyolite, West coast Coromandel, NZ ⚒️🧪🌊

Carlotta Maury bucked social norms as a paleontologist: a PhD by 1902, field work in southern US, Caribbean, S. Africa, and W. Europe, her own expedition to the Dominican Republic, one of the 1st women to become deeply involved in oil exploration. ⚒️🧪 www.geological-digressions.com/carlotta-mau...

My Earth Scientists feed is suddenly empty - anyone else? All the other feeds I follow are ok. ⚒️🧪🌊

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... ⚒️🧪🌊

Embarking on a new series-Mars geology and sedimentology. Not encyclopedic, hope they're useful www.geological-digressions.com/the-geology-... ⚒️🧪🔭 First 4: Martian Stratigraphy - The Framework Stratigraphy of the rocky planets Evidence for sedimentary rocks on Mars Mars orbiter and lander missions

Mignon Talbot (1869-1950) - a champion of women’s education. - 1st woman PhD at Yale 1904 - 1st to discover a dinosaur 1910 - 1st woman member of the Paleontological Society 1909 - 1st woman vice-president of the Paleo Soc 1926 www.geological-digressions.com/mignon-talbo... ⚒️🧪

From the Mid-Jurassic (Bowser Basin, British Columbia) thin section image of scaphopod shell X-section w geopetal mud infill (top to right). Original shell laminae still visible. Some neomorphism of calcite in the main shell. Geopetal void is lined by isopachous calcite. Left PPL, Right X polars ⚒️🧪

So the Department of Physics at the University of Auckland is looking to hire a lecturer/senior lecturer in one of the following areas: - Physics education research, - Quantum optics and quantum information, - Biophotonics and/or medical physics, - Astrophysics and/or space technology. 1/2...

My kids joke about my taking them to the beach to look at dynamic microcosms like this - fan delta progression during base-level (tide) fall (1 is oldest), channel incision, and forced regression. Image is about a metre wide. I mean - what could be more fun? ⚒️🧪🌊

This is what happens when a bunch of local South Auckland residents argue that a once verdant estuarine mangrove forest was unsightly - perhaps they prefer views of blackened stumps and mud ⚒️🧪🌊

Thin section image of Hawaiian beachrock - cross-section of a small gastropod partly filled by fibrous aragonite cement. Shell wall is layered - the thickest layer is radial calcite-aragonite crystal structure. Its neighbour (right) is a foraminifera. Plane polarized light ⚒️🧪🌊

Things to find on a sandy beach (NZ) - gastropods, bivalves, bryozoa, barnacles, fish, sponges, the internal shells of Ram's Horn squid (Cephalopod), crustaceans, seaweed - and the inevitable plastic ⚒️🧪🌊

I’m pretty sure all the astronomers already heard this bad news, but idk how many other folks know about this proposal—NASA science would be absolutely GUTTED if this passed. US astronomy & astrophysics would be dead. We can’t let this happen—tell your reps, & your friends! 🔭

Bouldery pocket beach and two sea stacks, east coast Coromandel, NZ. The near stack is very coarse lahar conglomerate, the far stack a jointed andesitic dyke. Taken just before Cyclone Tam hit, early April. The boulders moved a great deal during the storm surge ⚒️🧪🌊

The story of Mary Mantell, one of the 19th C hidden figures who found the 1st Iguanodon tooth (~1819-1822) is either lauded, or disputed as quaint and fictitious. Discovery of an 1887 newspaper article serves to resurrect her role in the discovery ⚒️🧪 www.geological-digressions.com/mary-ann-man...

A myriad spider webs, laced with early morning dew 🧪 #spiders #fall

The aftermath of some past storm. Subject to the vagaries of time and tide. All the textures and colours in this once vibrant root system, set against the constantly shifting sands; wave-washed ⚒️🧪🌊

Sand deflation on a wind-swept beach at the start of tropical cyclone Tam, April 16, east coast Coromandel, NZ. Couldn't get anywhere near this beach during the height of the storm ⚒️🧪🌊

A couple of introductory posts on Soft Sediment Deformation: more general statements - www.geological-digressions.com/soft-sedimen... and the 2nd on soft sed rheology - www.geological-digressions.com/rheology-of-... pretty much at undergrad level. ⚒️🧪

I have added the series 'Fossil morphology for sedimentologists', 8 invertebrate groups so far. Useful for initial field IDs. Access: Paleontology for sedimentologists www.geological-digressions.com/how-to-do-fi... or Describing sedimentary rocks www.geological-digressions.com/how-to-do-fi... ⚒️🧪