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. [gigapan id=”181069″] 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.