Geopedia, by Marcia Bjornerud

My favorite popularizer of modern geology is Marcia Bjornerud. Her sensibility for what is interesting and important matches very nicely with my own – I feel she is a kindred spirit, though one infinitely more talented with language than I am. Lovers of geology found much to delight them in Reading the Rocks. She took … Read more

Trace, by Lauret Savoy

I just discovered a 2015 book that explores the relation between the American landscape to the history of its people, indigenous, enslaved, and enslaver. The author, Lauret Savoy, is a professor at Mount Holyoke College, where she teaches in the department of environmental studies. In the book, Savoy explores the combined history of place and … Read more

Faults aren’t lines

A new post on GeoSpace, a sister blog here at the AGU Blogosphere, calls attention to a new study by Simon Lamb and colleagues on the plate-boundary fault running through New Zealand’s South Island, the Alpine Fault. The post is apparently taken and lightly adapted from a press release on the Victoria University of Wellington … Read more

Kopjes

Spheroidal weathering in Kruger National Park, South Africa. This outcrop is Archean granite of the Kaapvaal Craton. It’s producing a nice little inselberg in the low veld; good klipspringer habitat. “Kopje” is the word I learned to call these things in East Africa, but I guess the proper Afrikaans spelling is “koppie.”

Friday fold: one from Romney (West Virginia)

Last weekend, my wife and I joined friends for a weekend of cross-country skiing in the wonderful Canaan Valley of West Virginia. On the way back, between the towns of Burlington and Romney, West Virginia, I saw this folded shale on the north side of Route 50: You can click on that panorama to make … Read more

Friday (center)fold

At last weekend’s gala banquet to celebrate the 50th anniversary of the William & Mary geology department, I was tickled to see that the centerpiece for each table was a rock of some sort. I spotted Gore Mountain Amphibolite, Baker Mountain Kyanite, brachiopod fossils in limestone, a fossil whale vertebra, a chunk of Aquia Creek … Read more

Words matter

A table from the article “Communicating the Science of Climate Change,” by Richard C. J. Somerville and Susan Joy Hassol, from the October 2011 issue of Physics Today, page 48: There’s a lot to ponder in this table. It strikes me as an important document – a compilation of one of humanity’s most tragic miscommunications. … Read more

Geologic timescale names

The geologic timescale: Where did those names come from? Here’s some etymological information I share with my Historical Geology students so that the names become meaningful symbols of ideas, rather than simply of bunch of nonsensical gibberish to memorize… Phanerozoic eon – Greek for “visible life” Cenozoic era – Greek for “new life” Quaternary – … Read more

Aftershocks

Since Tuesday’s big earthquake, we’ve had 5* aftershocks in the same area (and possibly on the same fault). The most recent one popped off last night at 1am. Here’s a plot showing the size of the events (moment magnitude) relative to the passing of time: Note that the quakes that came after “the big one” … Read more

“Boudinage” is my favorite geology word

The current edition of the Accretionary Wedge geology blog carnival (hosted by Evelyn Mervine of Georneys) is built around the theme of favorite geology words. My favorite geology word is derived from the French boudin, for sausage. It’s “boudinage,” and it’s best said with a heavy French accent and a leering, dirty expression. “Boo-din-ahhdj” I … Read more

Let’s coin a name for this phenomenon

I didn’t mention it yesterday, but there was one other structure that I saw at my newest outcrop on New 55. This is it: That’s a bunch of fractures. The broken rock is being altered by preferential fluid flow through the fractures. The fluid is not inert; it’s chemically active, and reacting with the rock. … Read more

GoSF4: Kirby Cove

Part 4 of the ongoing series examining the geology of the San Francisco area. In today’s post, Callan visits Kirby Cove in the Marin Headlands, where intensely deformed chert can be found on one end of the cove, pillow basalts on the other, and an “artificial dune” in the middle.

Words’ worth IV

Back on the first incarnation of this blog, I occasionally posted about words that bugged me. A few more have piled up since then, so here we go with the latest consideration of “words’ worth”… First off, let’s consider the use of “outcrops” as a verb. This came up recently on this blog when commenter … Read more