You are browsing the archive for Callan Bentley, Author at Mountain Beltway - Page 2 of 196.
7 June 2023
The unconformity gets its portrait taken
Callan recounts a little lesson in taking a photograph of an outcrop that expresses itself more readily to the novice eye.
23 May 2023
Bird update May 2023
Click to enlarge Greetings friends … It’s been slow around the blog for some time now, and partly that’s due to being very busy with the spring semester, and partly due to a lack of inspiration. But I have been inspired to keep birding, and now that the books are closed on the semester, I have some time to sit and think and feel around for strands of creative inspiration. …
21 May 2023
Earthquake Storms, by John Dvorak
I’ve come to the end of my run of reading John Dvorak’s geology books. This is the fourth one for me to consume, but it was apparently the first he wrote. The topic is earthquakes, specifically those that occur along the San Andreas Fault in California. I’ve read a fair bit, it feels like, about the San Andreas: Carl-Henry Geschwind’s history, Susan Hough’s books, and just yesterday I started Andrew …
26 April 2023
Bird update April 2023
Click to enlarge Another month gone by… and spring migration is cranking along! I’m up to a 111 species in my county for the year so far. Migration is cranking right now, and there are lots of new species arriving each day (or just passing through en route to higher latitudes). I haven’t been making the most of it, frankly – due to family and work obligations, and a general …
26 March 2023
Bird update March 2023
Click to enlarge I’m still birding voraciously. I’m up to 89 species in my county for the year. So that means I added a dozen since last month. A few of those are freshly-arrived migrants from southerly climes, and some are just me putting in the time to go rack up waterfowl at nearby lakes. I’ve maintained my high county ranking, which has oscillated between #4 and #2 this month. …
17 March 2023
Friday fold: Pinto Gneiss, varnished and un-
Last week, I was lucky enough to visit Pushawalla Canyon in the Indio Hills region of southern California. There, my colleague Kim Blisniuk (San Jose State University) led our students through an exercise mapping alluvial deposits as a way of constraining offsets along the Mission Canyon strand of the San Andreas Fault. I noted that much of the alluvium was sourced to the northeast, to the Little San Bernardino Mountains. …
10 March 2023
Friday fold: Painted Canyon
Greetings from southern California! I’m running a spring break field course in the Mojave and Colorado desert. Here’s a pretty amazing fold pair in Palm Springs Formation, butted up against (darker) Mecca Formation along a fault. This is in Painted Canyon, in the Mecca Hills, a transpressional pop-up between the Painted Canyon Fault and the San Andreas Fault. Happy Friday!
25 February 2023
Bird update February 2023
Click to enlarge February has zipped by, but then again it’s a short month. I’ve continued birding intensively this month, so I’ll provide another update like I did last month. I’ve racked up 71 species this month, and pushed my 2023 total up to 77 (from January’s ending total of 66). The past few days have been very productive, as unseasonably warm temperatures have drawn north some early birds, such …
21 February 2023
Recent rocks
Trying to dredge up some blogging inspiration, but honestly I’m feeling underrested and overworked these days, and not particularly enthusiastic about writing. But here are some cool rocks I’ve seen lately; maybe you’ll find them interesting… Antietam Formation quartzite at Sherando Lake, Virginia: I was struck by how sugary the texture was, and the interesting joint patterns resulting in kind of bulbous forms. Graded bed of bioclastic debris, Martinsburg …
10 February 2023
Friday fold: Kelvin-Helmholtz waves in granite?
Reader Christian Gronau returns with another “guest Friday fold” submission. Christian writes, Greetings from a cold and wet west coast. A good time to root through old rock samples – and let the imagination run free … The little compilation below strikes me as visually compelling (both photographs are mine) – but how likely is it that the suggested analogy has any merit ? Would it have some …
Callan Bentley is Associate Professor of Geology at Piedmont Virginia Community College in Charlottesville, Virginia. He is a Fellow of the Geological Society of America. For his work on this blog, the National Association of Geoscience Teachers recognized him with the James Shea Award. He has also won the Outstanding Faculty Award from the State Council on Higher Education in Virginia, and the Biggs Award for Excellence in Geoscience Teaching from the Geoscience Education Division of the Geological Society of America. In previous years, Callan served as a contributing editor at EARTH magazine, President of the Geological Society of Washington and President the Geo2YC division of NAGT.