You are browsing the archive for April 2012 - Page 2 of 3 - Mountain Beltway.
17 April 2012
Strained Antietam Formation sandstone
I collected this sample the weekend before last on the Blue Ridge Thrust Fault field trip led by Alan Pitts. It’s a chunk of the Antietam Formation quartz sandstone, a Cambrian beach deposit. The face we photographed measures 15 cm by 12 cm. link It definitely looks best in full screen mode, so please feel encouraged to click through and explore it a bit. You’ll notice some great subtleties once …
16 April 2012
Sharing the M.A.G.I.C.
Last Thursday, my colleague Jim Buecheler and I took two students (Robin Rohrback and Alan Pitts) down to Charlottesville, Virginia, for a meeting at the state geological survey. The Department of Geology and Mineral Resources sponsors an annual one-day symposium on Virginia geology that I’ve participated in two or three times before. Last year I gave a talk, at the request of state geologist David Spears. This year, I gave …
14 April 2012
Students share their favorite parts of the eastern California trip
I did things a little differently in my latest field class, the Regional Field Geology of Eastern California. Instead of having a post-trip project (like I’ve traditionally done with my Montana/Wyoming Regional Field Geology course), I had the students complete a take-home test. I’ve just finished grading those tests, and was pleased to see the main themes of the trip were readily assimilated and applied by my fine team of …
13 April 2012
Friday folds: Turpan Depression
Rob Simmon of NASA’s Earth Observatory is the source for today’s Friday folds. Last week, he tweeted this image to me: That’s a excellent example of the outcrop pattern of a more or less horizontal outcrop of folded rock. To the north is a synform (notice that where streams have eroded it, the bull’s-eye pattern takes a notch inward toward the center of the structure), and to the south, a …
12 April 2012
Climate change books: fact & fiction
Callan reviews two books about climate change: the nonfiction account by Michael Mann, and a fictional thriller set in the warmed Arctic of the future.
11 April 2012
Blue Ridge Thrust Fault field trip
One of Callan’s former students leads a field trip to examine the western edge of the Blue Ridge geologic province, attempting to answer the question of whether the Blue Ridge / Valley & Ridge contact is indeed the trace of a thrust fault. Breccias and S-C fabrics tell part of the story…
10 April 2012
Macro GigaPans of Florissant insect fossils
Today, for your viewing pleasure, please check out five macro GigaPans of insect fossils from the Florissant fossil beds in Colorado (34.07 +/-0.10Ma). These amazing specimens were collected by Joe Cancellare, a student working on research supervised by Josh Villalobos of El Paso Community College in El Paso, Texas. Our M.A.G.I.C. project is helping Joe and Josh out by producing macro GigaPans for them. link link link link link All …
9 April 2012
Pliegue de Viernes? No, pero es una roca ígnea de México
I got an email a few weeks back from Moritz K., a PhD student at the Universidad Nacional Autónoma de México (UNAM) in Querétaro. He wanted to offer up a potential Friday fold. Here’s what he had to say: I wanted to send you a couple of pictures of folds I took in my PhD field area in southern Mexico in a tonalitic/dioritic, strongly banded sequence in the Totoltepec pluton …
6 April 2012
Friday fold: Japanese garden
Richard Littauer, a MSc student in Computational Linguistics at the University of Saarland (on Twitter at @richlitt) sent me today’s Friday fold. It comes from a garden at Nijo Castle in Kyoto, Japan. Definitely some wavy layers there. It’s a lovely specimen that would add gravitas to anyone’s garden. Not sure what it is – are these sedimentary strata or volcanic units? There’s plenty of sedimentary rock in Japan in …
5 April 2012
Red Bluff Granite, and what it intruded into
Returning to his February field trip in west Texas, Callan examines the contact zone where the Red Bluff Granite intruded into a group of surficial rocks, including columnar-jointed basalt.
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.