Today, we take a look at the structural geology that reveals the deformation evolution (first ductile, then brittle) of the South Mountains metamorphic core complex, south of Phoenix, Arizona. Expect lots of photos of smeared-out rocks, broken by faults.
Watch the flow of frictional melt in a “fossil earthquake,” frozen in time atop the South Mountains metamorphic core complex in Phoenix, Arizona.
A return to coastal Italy on this wintry Friday… You’ll recall that The Other Callan shared some fold imagery with us a few weeks back as he explored the Cinque Terre region of Italy. He is back in the States now, and has been kind enough to share his geology-themed photos with me, so I … Read more
Reader and former student Paxton DeBusk shared this lovely folded gneiss with me at the conclusion of the Virginia Geological Field Conference a few weeks ago: That’s a lovely hand sample, with a high folding:volume ratio! Happy Friday, all
I’m at the GSA Annual Meeting in Indianapolis this week, and I got an award today: the James Shea Award from the National Association of Geoscience Teachers. I was introduced at the awards luncheon today by my co-nominator Kaatje Kraft, who had many nice things to say. I followed her comments with this little speech: … Read more
The Friday fold comes to us from Corsica via University of Washington structural geologist Darrel Cowan. It’s a marble that’s been folded *twice!*
It’s been a very Billy-Goaty week for me. Three times since Sunday afternoon, I’ve taken people to the Billy Goat Trail’s “A” loop in C&O Canal National Historical Park. On Tuesday and Thursday, it was my NOVA Physical Geology students. On Sunday, though, it was just my son and me. Good news! He helped me … Read more
It’s Friday, thank goodness. Today our “Friday fold” feature heads north, way north, to the Brooks Range of Alaska. There we find a trio of mountainsides exposing folds photographed in the 1990s.
Mark Kurlansky might be the king of the micro-history. His books Salt and Cod were both excellent examinations of history in the context of those minerals and fishes. So when I saw The Big Oyster on the audio-book shelf at my public library, I checked it out, knowing roughly what I would get – a … Read more
It’s Friday; time to stretch our backbones out in anticipation of the weekend. Let’s look to a backboney-named Friday fold for a little inspiration… …And what’s that, just down the road? Another fold, in need of a catchy name…
A reader asks about Callan’s source of inspiration, a fitting question given the advent of Earth Science Week, which this year has as its theme “The Earth as Inspiration.” Brace yourself for a tantalizing cavalcade of gorgeous images of patterns in rocks!
For this Friday’s fold, we must journey to the storied Cinque Terre coastline of Italy, where we will encounter some mysterious turbidites…
It’s Friday and that means it’s time for a fold. Today we head to Cottonwood Canyon, Utah, with reader Octavia Spencer, for a lovely antiform.
It’s Friday! Here’s a lovely sight, contributed by reader Fred Atwood: [youtube_agu id=Au-jIGfbs8g] Those are quartz veins in one of my favorite local rock units, the Mather Gorge Formation. Fred reports, This is at Madeira School in Great Falls between Black Pond and the Potomac. The rocks around Great Falls, particularly those on the Billy … Read more
The talented science writer David Quammen has a new book out, and it’s excellent. The Tangled Tree explores endosymbiosis and horizontal gene transfer, two aspects of evolution that undercut the traditional ever-more-branching “tree of life” vision for the relatedness of living things. The lineage of organisms is not only divergent, but convergent too: populations diverge … Read more
A trip back to Archean sedimentary rocks in Barberton, South Africa, reveals a few folds on the roadside…
Yesterday, I finished listening to the audiobook version of A New History of Life, by Peter Ward and Joe Kirschvink (2016). This book is only a couple of years old, and takes as its topic ‘the modern perspective’ on life’s long history on Earth, using the latest insights available. It aims to debunk old hypotheses … Read more
After blogging about geovisualization, reader James Safranek alerted me to this new book about two of my favorite things: drawing and structural geology! I requested a review copy from the publisher, who kindly provided one. It’s great! This is “a whole book” about drawing and geology and specifically structural geology. As such, it’s not going … Read more
The first Friday of September calls out for a fold. The Burle Business Park in Lancaster, Pennsylvania has an answer – several of them, in fact!
TGIF: “Thank Geology It’s Friday!”
Time for a fold or a dozen – let’s travel to the Italian Dolomites to see some kinky crumpled limestones…