Hoo boy. This one made me yelp… While on the glacial geology of western Pennsylvania trip last Saturday, we visited a gravel quarrying operation. The operators were extracting gravel from a glacial lake delta deposit, and it was full of glacial outwash — sediments washed out from the melting front of the Erie lobe of … Read more
A new resource for the Japanese earthquake is online this morning, a “supersite” similar to the ones that exist for other huge events. Checking it out this morning, I found some interesting stuff. Over night, there have been more aftershocks, and here’s the most recent 600 or so events in the area, taken from IRIS’s … Read more
Callan begins a new series on the geology of Mount Washington, New Hampshire with a look at a roadside outcrop of metamorphic rock bearing enigmatic inclusions. Tourmaline-bearing pegmatites are also spotted.
I just got an e-mail which screams “scam!” Apologies for having to reach out to you like this, but I made a quick trip to the UK and had my bag stolen from me with my passport and credit cards in it. The embassy has cooperated by issuing a temporary passport, I just have to … Read more
So here’s how I made that cake I showed you Monday. Step 1: Collect the necessary ingredients: (Nice job with the stitching, Photoshop… jeez!) Step 2: Clear your schedule and start baking. My first layer was to be “the basement complex” and so I wanted something marbled in appearance. Mixing chocolate-powder-stained batter with regular yellow … Read more
Callan showcases his contribution to this month’s Accretionary Wedge blog carnival. The theme of the Wedge is “Bake Sale,” and Callan shows a cake he “discovered,” describing its geologic origin in detail. This would be tongue in cheek, except that his mouth is already full of dessert.
Just got this in an email: “Hi professor Bentley, This is [redacted], I had you for Geology last Spring. I just wanted to email you to first off, thank you, and second off, to ask some questions. Before I took your class Science was my worst subject , and I did everything to avoid taking … Read more
A diagram on “how science works” betrays an “experimentalist” bias. This sets Callan off on a rumination on the much-maligned validity of historical science, and that leads to a discussion of the Big Experiment, which is humanity’s influence on the Earth system.
Outcropedia launched yesterday, and I think it has the potential to be a cool resource for geologists and amateur geology aficionados. I’m particularly excited about the strong structural flavor of the featured outcrops so far. (The site was initiated by three structural geologists.) However, there are some issues that will need to be resolved. Ron … Read more
In honor of this month’s Accretionary Wedge (geoblog carnival; this month the theme is “deskcrops”), I recorded the following short video, showcasing some samples I have in my office: stromatolite (western Montana), conglomerate (Patagonia), schist (New Hampshire), anorthosite (New York), amygdular meta-basalt (Virginia), amphibolite (California), hematite concretions (eastern Montana), and a stretched-pebble lineated meta-conglomerate (Turkey).
With a helpful Twitter hint from Ron Schott, I won my second “Where on (Google) Earth?” challenge, the 214th edition of this popular geoblogospheric competition. As a result, I get to host the next one, Where on Google Earth? #215. The aim of the game is to figure out where on Earth this satellite imagery … Read more
Check out this video I found online whilst uploading last week’s Friday fold: This video was produced and published on YouTube by Markus Beckers, Michael Ketterman, Dennis Laux and Janos Urai. It’s a nice demonstration of how multiple layers of material of different properties and different thicknesses can yield up different flavors of folds. In … Read more
Back on the first incarnation of this blog, I occasionally posted about words that bugged me. A few more have piled up since then, so here we go with the latest consideration of “words’ worth”… First off, let’s consider the use of “outcrops” as a verb. This came up recently on this blog when commenter … Read more
Back on the first incarnation of this blog, I occasionally posted about words that bugged me. A few more have piled up since then, so here we go with the latest consideration of “words’ worth”… First off, let’s consider the use of “outcrops” as a verb. This came up recently on this blog when commenter … Read more
When I was done with my sophomore year at William & Mary, I embarked on a time-honored tradition among W&M geology majors: the Geology 310 Colorado Plateau field course. Jess alluded to this same course in her Magma Cum Laude contribution to this month’s Accretionary Wedge geology blog “carnival,” too. My version of Geology 310 … Read more
As with last week, I’m going to show you someone else’s fold today. This one should have strong resonance with most geologists, because it’s a fold in the tilted (and contorted) older strata exposed below the famous unconformity at Siccar Point, Scotland: I found this image on the British Geological Survey’s online repository of images, … Read more
Last week, I watched the BBC/National Geographic series “EARTH: The Biography,” hosted by Iain Stewart. Stewart is a charismatic host, with a thick Scottish accent that cannot disguise his enthusiasm for geology. The five episodes focus on: volcanoes, ice, oceans, atmosphere, and “rare planet.” Overall, I thought the series did an good job covering some … Read more
Over the summer, I went up to Vermont to visit my friends the Clearys. Joe Cleary is a college friend and a talented luthier. He and his wife Tree and their children Jasper and Juniper have settled in Burlington, a lively town with a lot of cool stuff going on. Joe took time out one … Read more
Folded & boudinaged granite dikes in tonalitic gneiss, Barberton granite-greenstone belt, South Africa. From Passchier, CW, Myers, JS, and Kroner, A., (1990). FIELD GEOLOGY OF HIGH GRADE GNEISS TERRANES. Very crudely annotated: This is a sweet example of how you can get different structures developing in different orientations relative to the principal stress directions. In … Read more