Lageson goes up
One of Callan’s former advisers, Dave Lageson of Montana State University, heads to the summit of the world’s tallest mountain with his graduate student, the accomplished mountaineer Conrad Anker.
Callan Bentley
Friday folds: Serendipity in the White Mountains
Callan and his field studies students encounter a lesson in the White Mountains of eastern California that combines bedding, cleavage, folding, and even fossil archaeocyathids!
An edgy outcrop
That’s a big pile of alluvial fan deposits (and colluvial debris?) on the eastern edge of the highway leading from Cape Town down to Rooiels. It’s not lithified, but it does seem to be at least partially cemented (perhaps by caliche?), because the outcrop face is essentially vertical, and there seems to be very little … Read more
Reef Madness, by David Dobbs
Callan reviews a book about the historical battle over the meaning of coral reefs. Protagonists include Charles Darwin and the son of Louis Agassiz. The book’s author, David Dobbs, answers some questions for Callan and readers.
Elevation 10,000 feet
White Mountains, California. Photo (and animated GIF) by Filip Goc. A little silliness for your Tuesday morning.
Views of the Deep Springs Basin
A few shots from a week ago today, when my students and I were exploring the White Mountains of eastern California, just west of the Deep Springs Basin…
Filip’s Friday Fold
While on Callan’s field course in eastern California, student Filip finds a lovely fold sample.
Poleta plume paradise
On Monday, my field course students and I tried to find the Poleta folds, but I had failed to figure out in advance the best access point. Oops. That’s the way the cookie crumbles, when you’ve got big plans but not enough time to enact them with appropriate pre-planning. We had some happy exploration of … Read more
Scenes from last Sunday: Bishop Tuff and Volcanic Tableland, CA
Sunday was our first full day in the field. Here’s a few looks at my NOVA students doing geology out in eastern California. We spent the day on, and next to, the Volcanic Tableland north of Bishop, a massive stack of ash fall and ignimbrite deposits erupted from Long Valley Caldera 760,000 years ago: the … Read more
Plane views
Some views from the airplane, over southern Wyoming (first two photos) and north-central Nevada (last four), last Saturday morning… A canyon: …and zooming in to the middle area of the previous photo: Strata upwarped into a structural dome (that has been “planed off” to be topographically horizontal, revealing a bull’s-eye-shaped outcrop pattern, then differentially weathered … Read more
Scott Mandia, climate communicator
Callan has a conversation with Scott Mandia, a community college professor working on the national level to improve the public’s understanding of climate science.
Scenes from Mono Lake
Yesterday I flew from DC to Reno, Nevada in the company of 11 students, and then we rented vehicles and drove south on Route 395, one of the greatest roads in America, to Bishop, California, where we area based for the next 3 days. We’re doing a regional field geology course examining the extraordinary rocks, … Read more
Friday fold: one from the Billy Goat Trail
Meter-scale fold in metagraywacke layers at the head of Mather Gorge, Maryland shore of the Potomac River, highlighted by differential weathering along the layering. Annotated interpretation: Happy Friday!
Sea Point Migmatite
Callan visits the Sea Point migmatite, a contact between intrusive granite and older metasedimentary rocks, along the west coast of South Africa near Cape Town. His guide? None other than AGU Blogosphere blogger Evelyn Mervine of Georneys!
This is a plant?
Weird plant from South Africa, in the north-central portion of Table Mountain National Park: it’s just two leaves! How bizarre is that? Two enormous leaves emerging from the leaf litter, nothing more. In Namibia, Welwitschia also have just two leaves, but they are much longer (and more prone to getting tattered). I’d love to learn … 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.”
One from the UTEP Reading Room
Incipient mylonitization of a granite/granitoid, as displayed in a sample on a shelf of one of the meeting rooms adjacent to the Reading Room of the Geological Sciences building at the University of Texas at El Paso. Same side, slightly different lighting conditions: I’d call this a protomylonite. Some of you might prefer the term … Read more
Friday fold: Veach Gap anticline, in GigaPan
GigaPan by Alan Pitts, as part of the M.A.G.I.C. project that we are working on. Here’s another one from a few meters away. Here’s a shot from 2.5 minutes after Alan saw this anticline for the first time. Here’s some shots of my own early visit to the site, after I first found it.
Contorted fractures in the Contorted Bed
Today, let’s zoom in on a little something I saw at the outcrop of the Contorted Bed in downtown Johannesburg, South Africa: What are these things? I only saw them at this one spot. These look to me like en echelon fractures at a high angle to bedding, that were then deformed due to dextral … Read more
Mudcracks worth writing home about
Some sweet “columnar jointing” style mudcracks from an abandoned quarry in about the farthest west corner of Texas that you can get to, or maybe the southeasternmost corner of New Mexico. One of them, anyhow… Did you spot the imposter?