Callan Bentley Books mentioned: Bones, Rocks, and Stars: the Science of When Things Happened, by Chris Turney Northwest Exposures: a Geologic Story of the Northwest, by David Alt & Donald Hyndman Geology Underfoot in Death Valley and Owens Valley, by Robert Sharp & Allen Glazner Stories in Stone: Travels Through Urban Geology, by David B. Williams The … Read more
I think snow can act as a nice analogue for larger-scale rock deformation. I explored this a bit last February, and I was reminded of it again last week, when I walked to my car one morning and saw this: Notice how the slab of snow on the hood (“bonnet” for British readers) of my … Read more
Norwegian structural geologist Haaken Fossen contributes two incredible images for this week’s Friday fold: a pavement of drastically-shortened banded iron formation from Minnesota, and a trio of three white granitoid dikes, buckled within a gneiss from the Jotun Nappe, in the Norwegian Caledonides. Gorgeous images of gorgeous folds, with links to the rest of Fossen’s collection.
Hopefully seasoned readers of this blog will remember this nice chunk of limestone with pyrolusite (MnO2) dendrites growing on its surface. I took some close-ups with my Nikon microscope a few weeks ago. Here they are; enjoy! The width of the field of view in each photograph is about 1.1 cm: BTW, Mike likes dendrites, … 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.
Join me in nominating David Bressan’s History of Geology blog for the Geological Society of America’s Mary C. Rabbitt History of Geology Award. To my knowledge, this would be the first time a blogger has won that honor. Every time I read one of David’s posts, I learn something new. I think it’s a wonderful … Read more
Recent discussion of the geologically incorrect cake t-shirt at Threadless (earlier take-down here) and the actual baked equivalent have inspired me to issue a call for Accretionary Wedge #30: Let’s have a Bake Sale! I hereby challenge my fellow geobloggers (and any newbies who want to participate) to explore the interconnections between geology and food. … Read more
A mystery rock is presented. Can you puzzle out what this beautiful thing is, and how it formed?
My once and future Honors student Robin R. brought back some sweet wavellite [Al3(PO4)2(OH,F)3•5(H2O)] samples from her holiday travels*. Check out these beautiful radiating crystals! A penny will serve as your sense of scale. The wavellite is a “crust” on top of a layered rock that appears to be a quartzite. (The layering in the … Read more
The weekly example of a fold is especially… “cool” this week.
Links, mostly to Amazon pages for the 6 books mentioned in the video: Thin Ice by Mark Bowen Ice, Mud, & Blood by Chris Turney Turney’s Twitter stream from Antarctica What’s the Worst that Could Happen? by Greg Craven Link to the AGU10 blog post mentioned and to Greg Craven’s response. The Carbon Age by … Read more
The final book I read over the break was Dirt: the Erosion of Civilizations, by David Montgomery. Montgomery got a MacArthur “Genius” Award for his soil work, and I use an article he wrote for GSA Today (2007) as one of the assigned readings for my Environmental Geology course. In Dirt, he lays out the … Read more
The final book I read over the break was Dirt: the Erosion of Civilizations, by David Montgomery. Montgomery got a MacArthur “Genius” Award for his soil work, and I use an article he wrote for GSA Today (2007) as one of the assigned readings for my Environmental Geology course. In Dirt, he lays out the … Read more
Here’s three shots of the Konnarock Formation diamictite, taken with my Nikon microscope. Field of view is about 1 cm in each shot.
Yesterday I mentioned some books that I had sampled on the topic of geologic time over the holiday break. Another book I read in my hammock in the Gulf of Honduras was Fads and Fallacies in the Name of Science, by Martin Gardner. As with Demon-Haunted World, I got the recommendation to read Gardner from … Read more
Yesterday I mentioned some books that I had sampled on the topic of geologic time over the holiday break. Another book I read in my hammock in the Gulf of Honduras was Fads and Fallacies in the Name of Science, by Martin Gardner. As with Demon-Haunted World, I got the recommendation to read Gardner from … Read more
Callan reviews four books about geologic time.
The final episode of the 10-part “Geology of San Francisco” series concludes with a visit to the spot where the San Andreas Fault runs off the edge of California and down into the sea. Mussel Rock, site of the opening vignette of John McPhee’s “Assembling California” is located there.
The Friday fold visits the French Broad Massif of North Carolina’s Blue Ridge province.
When I was out in California in October 2009, about the same time that Garry Hayes passed me on the highway heading up to Yosemite while I was headed down towards the Modesto Airport, I pulled over to check out some rock exposures on the side of the road. This was near the Don Pedro … Read more