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6 February 2013
Dinosaur footprints in west Texas
Everything’s bigger in Texas, even the footprints…
3 January 2013
Inside the French Thrust
Callan zooms in on the meso-scale structure of the French Thrust fault, exposed in Sun River Canyon, Montana.
6 December 2012
More xenoliths from the Boulder Batholith
The week before last, I showed you the Boulder Batholith, as it crops out southeast of Butte, Montana. Today, I’ll share a few more photos of xenoliths (or perhaps microgranular mafic enclaves?) from that same outcrop: Man, I miss that old Swiss Army knife. The damned security actors at Calgary Airport confiscated it last summer. 🙁
24 November 2012
Rock Cycle III: Igneous → Sedimentary
The Boulder Batholith outside of Butte, Montana, is actively weathering, and shedding off grus. In the third installment of the Transitions of the Rock Cycle series, we watch an igneous rock turn to sediment.
20 September 2012
Pachycephalosaurs were boneheads
This is a display at the Royal Tyrrell Museum in Drumheller, Alberta: It shows the domed skull of a pachycephalosaur: And it shows a virtual cross-section through that skull, revealing the size of the brain it protects: Weird animal. Great museum display: it says it all!
18 September 2012
Stratigraphy session
What are these students up to? I’ll give you a hint: this is Dinosaur Provincial Park in the Great Plains of southern Alberta. The badlands style topography here offers a nice vertical section through clastic sedimentary rocks originally deposited adjacent to the Western Interior Seaway. On our Canadian Rockies field course in July, my co-instructor Pete Berquist (from Thomas Nelson Community College in Hampton, Virginia) led an afternoon exercise in …
20 August 2012
Morning with the local expert
Royal Tyrrell Museum geologist Dave Eberth donates time and expertise to help Callan’s students understand the Cretaceous-aged Horseshoe Canyon Formation in central Alberta.
16 August 2012
Bearpaw bivalves
Cretaceous clams from the final big transgression of the Western Interior Seaway, the “Bearpaw Sea”: We saw these last month at Devil’s Coulee in southern Alberta. They’re big!
14 February 2012
Contact of the Campus Andesite with host rocks
First thing we saw on the post-InTeGrate field trip to the rocks of El Paso, Texas, was this contact between the aforementioned Campus Andesite, and the Cretaceous sedimentary rocks into which it intruded (contact metamorphosed in the area of this photo): I decided to try switching up my annotation fonts. Whaddya think?
3 August 2011
Gigapan of the French Thrust
To follow up on my March post on the French Thrust, here’s a gigapan of the outcrop. Sun River Canyon, Montana, of course: the Sevier fold-and-thrust belt.
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.