Callan Bentley You may recall that I kind of like boudinage. So it piqued my interest when our field trip leaders (on the pre-GSA Minneapolis trip to examine the structural geology of the sub-province boundaries in the Superior Craton) said our next stop was to visit “pseudoboudins,” segments of granitoid pegmatites that looked like boudins but probably … Read more
Today’s fold is an anticline and its neighboring syncline, both exposed along a newly-opened stretch of New Route 55, west of Moorefield, West Virginia. The new Route 55 is a classic porkbarrel boondoggle courtesy of the late Senator Robert Byrd, but doggone if it didn’t open up some lovely new roadcuts. Here’s a stitched image … Read more
After the awesome outcrops and pavements of strained metaconglomerates from the Quetico / Wabigoon subprovince boundaries of the Superior Craton, my pre-GSA field trip visited the most charmingly-named magma chamber I’ve ever seen, the cuddly-sounding Ottertail Pluton. This is an Algoman-type pluton which is discordant to tonalite-composition gneisses in the area. As with the Giants … Read more
Here’s the talk I gave at GSA last month: [youtube=”http://www.youtube.com/watch?v=oXt5aZIu5Xk”] It’s presented here at a slower pace than the actual talk was, since I didn’t have to run and catch a plane 45 minutes after presenting it, but there are some PowerPoint bugs with some of the animations. Oh well – recording it and … Read more
Here’s what I did for my Halloween costume this year. I decided to be a frog egg mass, with spawning frogs spewing gametes all over in a big orgiastic mess. Start with one ‘normal’ Callan: Switch to frog-egg colored clothing: Don a pair of foam packing bubble wrap “trousers: Add a “tunic” of bubble wrap, … Read more
The root of every issue that we collectively term “environmental problems” is human overpopulation. It wouldn’t matter if everyone on Earth drove a Hummer and used incandescent light bulbs and dumped raw sewage in their local watershed — if there were only fifteen people on the Earth. But the reverse is also true: if everyone … Read more
One of the 300 or so blogs that I read is by Dr. William Hooke, a senior policy fellow at the American Meteorological Society. I met Bill half a year ago, when I came to a joint AGU/AMS social media training session at the request of my keepers at the American Geophysical Union. I shared … Read more
This summer, a week or two after our wedding, my wife and I found ourselves in the Canadian Rockies for a pre-honeymoon. Part of our time was spent on a backpacking trip to Floe Lake in Kootenay National Park, British Columbia. On our hike in, we passed this outcrop of Chancellor Slate, a Cambrian aged … Read more
Picking up from the astonishing first couple of outcrops we saw of strained Seine Group metaconglomerate from the boundary between the Wabigoon and Quetico sub-provinces of the Superior Craton, our group moved on down the road. It was lovely clear fall weather near Fort Frances, and shockingly warm. Our third stop of the morning was … Read more
Why are these geologists all over these rocks? Because, gentle readers, these are some seriously cool rocks. The geologists are all participants on a pre-GSA-annual-meeting field trip to the Superior Craton, a chunk of ancient crust at the “nucleus” of the North American continent. The rocks are syn-tectonic volcaniclastic conglomerates of the Seine Group. They … Read more
Some fall photographs from 2007, taken of the south fork of the Shenandoah River, southeast of Massanutten Mountain, in Virginia’s Valley & Ridge province. Photos are by my NOVA colleague, the biologist (and pilot) Mike Peglar: Our leaves are changing color now, and I’d imagine if we were soaring over the Shenandoah Valley this morning, … Read more
Wednesday, Alton Dooley put up a post about his visit to Van Hise Rock in Wisconsin. He included this photo of the famous rock with its upright (pretty much vertical) layers: Go read his description of the lithology for more detail, but essentially what you see here is an Oreo-like sandwich: pink quartzite (meta-sandstone) on … Read more
Here are the bookmarks in my web browser’s “geology” folder. You may find some useful stuff here. Enjoy. Geological Society of Washington Earth Revealed videos EARTH Magazine Geotimes UMD Geology Seminar Series GSA Journals Evolution of the Earth Appalachian Structure Primer USGS Water Data for LITTLE FALLS GAUGE Difficult Run gaging station data NOAA Potomac … Read more
Elizabeth Eide of the National Academies shared this image with me a year or two ago, when she gave a talk on Norwegian geology for the Geological Society of Washington. Those are some bookshelfed gneiss layers sandwiched between upper-left and lower-right carbonates. The “bookshelfing” refers to the numerous parallel brittle fractures along which the gneiss … Read more
Just because I felt like making something silly…
A table from the article “Communicating the Science of Climate Change,” by Richard C. J. Somerville and Susan Joy Hassol, from the October 2011 issue of Physics Today, page 48: There’s a lot to ponder in this table. It strikes me as an important document – a compilation of one of humanity’s most tragic miscommunications. … Read more
Two images that have me scheming to go down to Veracruz, Mexico, next September for a weekend of hawk-watching: …Impressive, no? Better yet, check this out: …Oh. Yeah.
I read an article in the current issue of Physics Today with interest. It deals with the nature of scientific controversies, as percieved by the public and by specialists in the field in question. The author, Steven Sherwood, compares the origin of the ideas of a heliocentric solar system, general relativity, and human influence on … Read more
This is a boulder of Cambrian-aged Flathead Sandstone, the unit overlying the Great Unconformity exposed in Wind River Canyon, Wyoming. Click to make it 5000 pixels wide. Swiss Army knife for scale. It shows a lovely example of multiple upside-down cross-beds. It also shows a heavy layer of caliche on what is (now) the upper … Read more
The “Friday fold” is an isoclinal dextrally-asymmetric granitoid vein exposed north of Fort Frances, Ontario. Taken on October 7, 2011, the photo features a centimeter-demarcated pencil for scale. It shows thickened hinges, boudinage of the lower right long limb, and incipient boudinage of the upper left long limb.