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11 March 2011
Art imitates art
Something occurred to me this morning when I saw this: (source) …And it was this: (source) Do you think it’s a coincidence that NOAA’s mapmaker chose that particular royal blue / sky blue / white color scheme, augmented by gray continents with yellow accents? I suspect it’s a beautiful shout-out to the classic piece of tsunami art. The reality is that tsunami are often a horrid brown gray color, full …
Friday fold(s): Mount Washington 2
More from Mount Washington, New Hampshire: some folds in the Madison Member of the Littleton Formation (schist) along the auto road near Cragway Springs (just past 5 miles up; see map below): IMAGE SOURCE The folds are asymmetrical, with long west-dipping limbs, and shorter east-dipping limbs. Happy Friday!
Japan M8.9 quake + tsunami
I’m not usually the “report on current events” type of geoblogger, but someone needs to throw a few details up ASAP for those who are interested in the details of the big Japanese earthquake and resulting tsunami that is currently crossing the Pacific Ocean. First off: links to other geoblogs already reporting on the event: Geotripper, Paleoseismicity, Hypo-theses, Dan’s Wild, Wild Science Journal , Eruptions, Georneys, Hudson Valley Geologist, and …
9 March 2011
A portrait of the feldspar as a young mineral
A few microscope photos for you, showing close-ups of feldspars in igneous dikes in the Crazy Mountains of Montana… You’ve seen these rocks before, when I posted a few field photos from this area in August 2009. I took these images of feldspar phenocrysts in a hand sample (from a quartz latite dike) with my no-longer-brand-new Nikon microscope camera: There’s some nice compositional zoning going on in some of these …
8 March 2011
A couple other Montana shots
Friday’s prompt to post the French Thrust shot gave me the opportunity to dig into my “Rockies” folder a bit. Here’s two other shots from my inaugural summer leading my Geology 295 field class out there. Hiking the trail to Grinnell Glacier: …It looks like we’re in the Appekunny Formation here, third from the bottom in the stack of Belt Supergroup strata at Glacier. In the distance, you can see …
7 March 2011
Books about atheism
I’ve been reading some books lately about atheism. Though I’ve been a functional atheist for many years, I’ve been paying more attention to it lately in light of religiously-inspired idiocy from around the globe. I’ve become convinced that religious belief does more harm than good, and my sense of incredulity has deepened at how far my fellow humans will go in their own self-deception. So I’ve been doing some reading …
6 March 2011
French Thrust
That title sounds kinky, right? Well, calm down. I’m behind the curve on the latest Accretionary Wedge (as I was for the one before that), but here’s a quick image to join the parade of geologic photos that Ann is hosting. While it’s not my favorite, it’s definitely a favorite, more by virtue of the geology it shows than the aesthetic qualities of the image: That is an outcrop of …
5 March 2011
Buzzard Rock
Took a hike this morning with my bride-to-be, out to Buzzard Rock on the northeastern corner of Massanutten Mountain. There, we observed numerous boulders of Massanutten Sandstone float, many bearing charismatic cross-beds. Here’s one more slab of float, presumably weathered out along the main bed, showing gorgeous internal cross-stratification: A closer look at the left side of this sample, animated via GIF: Why animated? Because I can. The object of …
4 March 2011
Friday fold: Buckled vein in the Catoctin
Another fold seen in the Catoctin Formation, where last week we encountered a very different style of folding — chevrons overprinting Catoctin foliation. Here, we instead have a light colored vein that appears to have been buckled into a semi-ptygmatic form. The trace of the foliation in the Catoctin is discernible, too. Enjoy your Friday!
1 March 2011
News from the Billy Goat Trail (3): grab bag
Okay, a final post (for now, anyhow) sharing some images from last Friday’s field trip to the Billy Goat Trail, in Potomac, Maryland. Yesterday we looked at lamprophyre dikes, but there are other dikes on the Billy Goat Trail, too. Like this granite pegmatite: What’s interesting to me about this is that the joint set seems to have contradictory cross-cutting relations with the dike. Did the joints come first? Or …
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.