You are browsing the archive for February 2012 - Mountain Beltway.
29 February 2012
This is a plant?
Weird plant from South Africa, in the north-central portion of Table Mountain National Park: it’s just two leaves! How bizarre is that? Two enormous leaves emerging from the leaf litter, nothing more. In Namibia, Welwitschia also have just two leaves, but they are much longer (and more prone to getting tattered). I’d love to learn what this thing is – botanical experts, please chime in if you know.
28 February 2012
Kopjes
Spheroidal weathering in Kruger National Park, South Africa. This outcrop is Archean granite of the Kaapvaal Craton. It’s producing a nice little inselberg in the low veld; good klipspringer habitat. “Kopje” is the word I learned to call these things in East Africa, but I guess the proper Afrikaans spelling is “koppie.”
25 February 2012
One from the UTEP Reading Room
Incipient mylonitization of a granite/granitoid, as displayed in a sample on a shelf of one of the meeting rooms adjacent to the Reading Room of the Geological Sciences building at the University of Texas at El Paso. Same side, slightly different lighting conditions: I’d call this a protomylonite. Some of you might prefer the term “augen orthogneiss.” No systematic asymmetry of the feldspar porphyroclasts is catching my eye on either …
24 February 2012
Friday fold: Veach Gap anticline, in GigaPan
GigaPan by Alan Pitts, as part of the M.A.G.I.C. project that we are working on. Here’s another one from a few meters away. Here’s a shot from 2.5 minutes after Alan saw this anticline for the first time. Here’s some shots of my own early visit to the site, after I first found it.
23 February 2012
Contorted fractures in the Contorted Bed
Today, let’s zoom in on a little something I saw at the outcrop of the Contorted Bed in downtown Johannesburg, South Africa: What are these things? I only saw them at this one spot. These look to me like en echelon fractures at a high angle to bedding, that were then deformed due to dextral (top to the right) shearing. But they’re really closely spaced, and they show no apparent …
22 February 2012
Mudcracks worth writing home about
Some sweet “columnar jointing” style mudcracks from an abandoned quarry in about the farthest west corner of Texas that you can get to, or maybe the southeasternmost corner of New Mexico. One of them, anyhow… Did you spot the imposter?
21 February 2012
New GigaPans: source and sediment
New M.A.G.I.C. GigaPans are shown of two connected Hawaiian samples: one an igneous rock, one a loose beach sand.
How could thematically-linked images like these be used to further geoscience education?
Got any ideas?
Chime in!
20 February 2012
Mystery rock
Here’s a mystery rock that’s just aching to have its identity be crowdsourced: I got these photos from Rick Diecchio of George Mason Univerisity, who got them from a local fellow who dug it up in his yard in Dale City, Virginia. Rick says: I was stumped at first, but the more I look at it, the more I think it’s a lightning strike into sand or more likely sandstone, …
Honey, I shrunk the grad students
On the airplane ride back from Texas, I bought a copy of Michael Crichton’s semi-posthumous final novel, Micro, which was co-authored by Richard Preston after Crichton’s death in 2008. Preston wrote a superb book about Ebola virus in the DC area, so I was intrigued to see his influence. Plus, and of utmost priority, I just wanted some light reading for the plane. It was mediocre. If you’ve read Sphere, …
19 February 2012
Plane views
A few scenes out the left side of the airplane from when I flew from El Paso to Houston a week and a half ago… Sand dune field overprinting desert vegetation and human roadways: Outcrop pattern of horizontal strata (tracing out the contours of this hill), and the weird geometry of human road systems: More contour-hugging outcrops of horizontal strata, and a vertical joint set: Same thing: Bajada (apron of …
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.