Friday fold: Folded Mountains Ale
My friend Eric Pyle drew my attention to this ale earlier in the week – I reckon that will do for this week’s Friday fold. Cheers! And Happy New Year!
Callan Bentley
2015 Yard List
It’s that time of the year – a time to state my “yard list” tally for the previous year. I have been posting this list every year since I moved to the Fort Valley: 2012 (39 species) 2013 (51 species) 2014 (58 species) In 2015, we had 65 species of birds spotted and definitively identified … Read more
Serpentinite mélange on Marshall’s Beach
South of the Golden Gate Bridge in San Francisco, there are beachside exposures of serpentinite mélange: tectonically sheared-out former oceanic crust accreted to western North America as part of an accretionary wedge.
Corona Heights Fault, San Francisco
At the end of the AGU Fall meeting, Callan visits the Corona Heights “mirror” fault, renowned for its gorgeous slickensides. Explore the site in photos in GigaPans.
Superintelligence: Paths, Dangers, Strategies, by Nick Bostrom
How much thought have you given to the consequences of achieving an non-biological intelligence? If you’re like me, you’ve thought about the notion in a Hollywoodized sense, but once you get out of the cinema showing the latest Terminator film, you might not dwell on the topic too much further. I’ve given artificial intelligence (AI) … Read more
Cryptonomicon, by Neal Stephenson
Because I was impressed with Seveneves, I decided to make my next read another novel by Neal Stephenson. There are several highly-praised options to choose from, but the one that came to hand first in the library was 1999’s Cryptonomicon. It’s a monster of a tome, clocking in at just over 900 pages, which is … Read more
Four new GIGAmacro images of sedimentary rocks
It’s been a week and a half since Mountain Beltway has seen any publishing action, given the overlapping timesucks of the AGU Fall Meeting and the end of the semester. But now I’m back in the Appalachian mountain belt, and my grades are all in, and I have time to think about indulgences like blogging … Read more
Friday fold: Nice gneiss from Salt Lake, Utah
Another guest Friday fold… this one from my colleague Tiffany Rivera of Westminster College in Salt Lake City, Utah, the one who brought you yesterday’s thrombolite pictures… Tiffany writes that these shots come from a man-made boulder field / berm along the lake. The boulders were these beautifully folded gneisses. Antelope Island exposes some of … Read more
Thrombolites of the Great Salt Lake, Utah
I saw mention of thrombolites exposed along the shore of Antelope Island in the Great Salt Lake the other day in my Facebook feed; because the description cited a professor at Westminster College in Salt Lake City, I prompted my friend and colleague Tiffany Rivera, also a geology professor at Westminster, to go check it … Read more
Considering the Spechty Kopf diamictite
I have known for a long time about a diamictite in the latest Devonian part of the Appalachian stratigraphic sequence, since it is exposed in the lowermost part of the section (western end of the outcrop) at Sideling Hill, Maryland. When I led field trips there, I talked students through the multiple possible origins for … Read more
Friday fold: interference patterns on Elba
Samuele Jæger Papeschi shares one more fold with us: some deformation here… type III (Ramsay…) interference pattern in Cretaceous calcschists… Cavo, Elba Island Awesome! I hope everyone has a great Friday.
Which way’s up? Check cavity fills.
When snail shells are deposited in a bunch of sediment, they serve as tiny architectural elements, with a “roof” that protects their interiors. Any sediment mixed into the shell’s interior will settle out (more or less horizontally), and then there will be empty space (filled with water, probably) above that. As burial proceeds and diagenesis … Read more
Slump in progress on Corridor H
I was out on Corridor H last week, looking at rocks with my Honors student, and on the way back from the field work, I noticed this: Click to enlarge That’s a fresh slump scarp running across a slope that is gradually sliding downhill. (The left half of the image is moving down relative to … Read more
Seveneves, by Neal Stephenson
At first, I thought the titular Seveneves referred to fragments of the Moon. It blows up on the first page of the novel – or disaggregates anyhow, into seven big chunks. But these start knocking into one another, breaking off smaller pieces, and these bang into each other, making more pieces. Soon, there are a … Read more
Friday fold: recumbent limestones of coastal Grosseto
Samuele Jæger Papeschi not only provided this week’s Friday fold, but he also serves as its sense of scale: According to Samuele, these are: folded metalimestones in Punta delle Rocchette, Grosseto. This are pretty interesting transected folds, showing about 10 degrees of foliation dip in respect to their axis Thanks for sharing, Samuele, and happy … Read more
A little geologic history before breakfast
What geological stories can be read from the stone on the front of a building? Walking past some facing stone in Baltimore, Callan discovers a wealth of little clues.
Beach sand of coastal Maine
You could use a macro GigaPan of some pretty sand, I think. Link That’s sand from near Acadia National Park, in Maine. Exploring it, you can find both small chunks of Acadian granite, and green rods that are sea urchin spines. It’s fun – check it out.
Hitting a nerve with popular posts
I blog here a few times a week, when I can manage it. Mostly I focus on new things I discover on field trips, advances in geologic imagery, and structural geology. I get about 500 readers per day. But occasionally I write about other things, like creationism or current events disasters like earthquakes, and those … Read more
“Making North America,” episode 3: Human
The PBS series NOVA has a new three-part series called “Making North America” that premiered two weeks ago. Hosted by the director of the Smithsonian Institution’s National Museum of Natural History, Kirk Johnson, the series explores the tectonic assembly of terranes that resulted in the bedrock of the continent, the panoply of diverse creatures that … Read more
Friday fold: chevron-folded chert
Samuele Jæger Papeschi is the source for today’s fold: Those are: chevron-folds in radiolarian cherts – Jurassic radiolariti fm. – Quercianella – Leghorn, Italy Cool. They look a lot like the chevron-folded cherts near San Francisco. Same age, too.