Lightnews — Scholar-powered news

Brian Ricketts @kiwigeolog.bsky.social · 1d

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. ⚒️🧪🌊

1 4 22

Brian Ricketts @kiwigeolog.bsky.social · 4d

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). ⚒️🧪

2 9

Brian Ricketts @kiwigeolog.bsky.social · 10d

Lava tubes are usually at very shallow depths with physical connections to the surface. So atmospheric pressure would still be 92 times that on Earth and temperatures 400C or more. Even robotics will have a hard time surviving

Brian Ricketts @kiwigeolog.bsky.social · 11d

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 ⚒️🧪

2 23

Brian Ricketts @kiwigeolog.bsky.social · 13d

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

1 5 18

Brian Ricketts @kiwigeolog.bsky.social · 19d

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...

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.

www.geological-digressions.com

2 17

Brian Ricketts @kiwigeolog.bsky.social · 20d

Change the matrix label

Brian Ricketts @kiwigeolog.bsky.social · 20d

Is there a fabric?
Groundmass or matrix? Do they know the difference?
Can they zoom in - identify cleavage-twin planes in the phenocrysts.

1

Brian Ricketts @kiwigeolog.bsky.social · 22d

A penetrative fabric that looks vaguely shattercone-ish? 🔭

1

Brian Ricketts @kiwigeolog.bsky.social · 24d

OK I did mean the wispet star/sun, not our own 😁. But thanks for the reply and answer in the thread.

1

Brian Ricketts @kiwigeolog.bsky.social · 24d

Probably a silly question but if this is imaged in the H frequency (or is it?) why don't we see the sun - or does the H-alpha frequency render the sun not visible? What am I missing here?
Thanks.

1 1

Brian Ricketts @kiwigeolog.bsky.social · 26d

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

5 24

Reposted by Brian Ricketts

bse @doktrock.bsky.social · Sep 10

⚒️🧪

1 1

Brian Ricketts @kiwigeolog.bsky.social · Sep 9

Just added ash, bomb, ballistic, glass and obsidian to the etymologies page. And I discovered that obsidian is actually a miss-spelling - the 'Latin is obsianus (lapis) - dark stone - it seems the d was added in error! 😁

2 2

Brian Ricketts @kiwigeolog.bsky.social · Sep 8

Just added the word "ash"

Brian Ricketts @kiwigeolog.bsky.social · Sep 8

Thanks for the info. Filed away. Mary S is on my post list of 'Pioneering women in Earth Science, but I'm working in alphabetical order and only up to the Ps

1

Brian Ricketts @kiwigeolog.bsky.social · Sep 8

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. ⚒️🧪🌊

Etymology of Earth science words and phrases

The origins of words, prefixes, suffixes, abbreviations, names, acronyms, and terms commonly used in Earth sciences.

www.geological-digressions.com

1 14 67

Brian Ricketts @kiwigeolog.bsky.social · Sep 6

90% of posters at most conferences I've attended could have been designed with 90% less text (including a few of my own). Amount of text here is pretty reasonable I think. I like the design

1

Brian Ricketts @kiwigeolog.bsky.social · Sep 5

That's two words. I used one

Brian Ricketts @kiwigeolog.bsky.social · Sep 5

Quite right. I'll add an entry for Earth, as soon as I think of something useful, plausible, meaningful

1

Brian Ricketts @kiwigeolog.bsky.social · Sep 4

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-...

Glossary of planetary geology

Glossary of planetary geology, the Solar System, moons, asteroids, comets, meteorites, exploration, and related terminology

www.geological-digressions.com

6 3 14

Brian Ricketts @kiwigeolog.bsky.social · Sep 3

No mean feat indeed! Women were not permitted as Fellows of the GS until 1919 - she was elected 1982. The GS was dragged kicking and screaming into a (slightly) more inclusive 20th C

1

Brian Ricketts @kiwigeolog.bsky.social · Sep 3

Nice to hear from you Elisabeth.

1

Brian Ricketts @kiwigeolog.bsky.social · Sep 3

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...

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...

www.geological-digressions.com

1 4 8

Brian Ricketts @kiwigeolog.bsky.social · Sep 3

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...

Experimental sequence stratigraphy: model attributes

This post describes the experiment methods and boundary conditions of a scale-independent, experimental stratigraphic model

www.geological-digressions.com

4 7