You are browsing the archive for ice Archives - Page 3 of 3 - Mountain Beltway.
30 March 2012
Friday fold: ice in Iceland
Searching for Peter Luffi’s latest Where On Google Earth? challenge, I found myself touring Iceland last week. While I didn’t find the strange comet-shaped feature he posted, I did find this: And zooming in a bit, to the high-contrast area in the center: This appears to be volcanic ash layers distorted by glacial flow and then melting/sublimation/weathering/erosion/ablation of the glacier. I posted something similar as the Friday fold almost a …
20 January 2012
Friday fold: one from Romney (West Virginia)
Last weekend, my wife and I joined friends for a weekend of cross-country skiing in the wonderful Canaan Valley of West Virginia. On the way back, between the towns of Burlington and Romney, West Virginia, I saw this folded shale on the north side of Route 50: You can click on that panorama to make it a thousand pixels tall, if you want to explore it a bit. There are …
22 November 2011
Asbest-ice
On our way up Compton Peak the other day, my field crew spotted some fibrous growths of ice growing up and out of the ground (perpendicular to the surface of the mountain): (Joe’s hand lens for scale.) The fibrous habit made me think of asbestos, and then I wondered whether the different shapes of ice crystals reflect different mineralogical arrangements of the H and O atoms, and if they are …
8 August 2011
Climbing Darton Peak
Callan embarks on an exhausting climb of a major summit in the Wyoming Bighorn mountains, a peak named in tribute of one of his geological heroes. Come join the trek to the top of Darton Peak!
29 April 2010
Mineral phantasms?
Ice… serpentine… halite… What do they all have in common? I’ve discussed mineral “ghosts” here before — really, those are only pseudomorphs, where one mineral’s chemistry becomes unstable due to a change in conditions, and then a new mineral forms in the same space. I’ve also brought up the issue of clasts of minerals which are unstable over the long term (ice). Last night, at the final meeting of the …
8 March 2010
When the Sturtian happened
Last Friday, I spent the evening riding up to New York on a bus. To pass the time, I had my iPod and a new paper by Francis Macdonald and colleagues in Science. The paper examines the timing of one of the episodes of “Snowball Earth” glaciation. There’s some important new data in this paper, and it helps constrain the “Sturtian” glaciation in time. So here’s the deal with Precambrian …
27 February 2010
Frozen soil lifts off
When I was out poking around in the woods, confirming for local geophile Barbara that indeed her local geologic map wasn’t 100% accurate, I noticed this on the frozen ground: We have seen this before, in a post back on NOVA Geoblog, almost exactly a year before I took this photo. Here’s another shot from the more recent excursion, taken a foot or so over from the first one: What’s …
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.