20 May 2013
Monday macrobug: A golden weevil
Spring is back in the Fort Valley, and that means many serendipitous bug encounters. I think it’s safe to say that the Monday Macrobug is back as a regular feature on Mountain Beltway for the foreseeable future! Today, I give you…. a weevil!
You’re welcome.
17 May 2013
Friday fold: Rorschach blot
The broad symmetry (with smaller-scale variations) of this fold caught my eye as particularly artful when I saw it (at Howard’s recommendation) last summer in the Canadian Rockies:
Kootenay National Park, British Columbia, Canada.
I see a butterfly. What do you see?
Happy Friday.
16 May 2013
GigaPanning Kilbourne Hole
Kilbourne Hole is the crater of a maar volcano in southern New Mexico, just across the state line from El Paso, Texas.
I went there the weekend before last with a team from El Paso Community College, led by Joshua Villalobos. This is the place where xenobombs come from!
If you go to the right area, you can find dozens of these mantle xenoliths sheathed in fine-grained basalt, like chocolate-coated peanuts. There are also lower crustal xenoliths; gneisses and stuff like that. But nothing beats peridotite for sheer ‘otherworldly’ beauty and awe.
We also saw these beautiful outcrops of volcanic blocks that got ker-plumped down into the pyroclastic surge deposits:
Ron Schott produced a wonderful overview GigaPan of the site back in 2009:
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So rather than the broad landscape, we concentrated our efforts on smaller outcrops, like this informative scene:
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Annotated:
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Same place, zoomed out a bit, and from a higher perspective (and a bit overexposed):
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Annotated:
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Now for the really sexy stuff! Here is one of those volcanic block plopped like a dropstone into the pyroclastics:
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Another, similar scene…
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And closer in:
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I trained Josh and his students on the use of their new GigaPan, and we had a great time. Here’s the El Paso CC / UTEP team on the rim of the Hole:
15 May 2013
Dark Star Safari by Paul Theroux
The week before last, on the flight home from Texas, I finished reading Dark Star Safari, Paul Theroux’s 2004 account of traveling overland through Africa from Cairo to Cape Town. I’ve enjoyed Theroux’s traveling writing very much over the years, and although he’s written some great novels (I’m thinking of Mosquito Coast), most of them don’t appeal to me as much as the travelogues do.
I’ve been reading a lot lately, but most of it has been for book reviews that will be published in upcoming issues of Earth magazine. But this one has been on my shelf for a while, and I’ve been meaning to read it since it was published nine years ago. I enjoyed it. I’ve taken three trips to Africa in my life: Namibia in winter of 1996-7, Tanzania and Kenya in summer 2002, and then South Africa most recently in the winter of 2011-2012. Three of those four countries were on Theroux’s route south (see map below).
Why read a travelogue like this? For me, it’s an easy way to dip into the experience of travel (the good, the bad, the ugly) without any of the hassle or risk. Theroux gets into some hairy situations, and he ventures to inhospitable places – the real Africa, off the tourists’ well-beaten path. I like reading about decision-making as to logistics of how to get from point A to point B, or solving the problems of being away from home, out experiencing the world. I like the commiseration I feel when I read of Theroux crammed into a matatu with a dozen other people, of dealing with intestinal distress abroad, of arguing with mean-spirited people. All are familiar experiences to the traveler in Africa, and the great thing about a travelogue is that you can close the book and turn out the light when you want. Unlike actually being there, there’s nothing to compel you to resolve things ASAP, and for some reason, I like that.
The chief take-away message from the book is one of policy. Wherever Theroux traipses in East Africa, he finds do-gooders from the West mucking things up. He concludes that Western aid to Africa ultimately does more harm than good, as it enables corrupt government and encourages a “handout” mentality. Whether you agree with that assessment is of course up to you, but I’ve got to admit that he makes a pretty compelling case, with anecdotes and interviews aplenty as evidence. The most heartbreaking part of the book is when he revisits his former Peace Corps site in Malawi. There, he finds his old school in ruins, ransacked and gutted by thievery and disrespect. Some of his former students are now government ministers, and he gets together with them to bemoan the country’s descent into squalor. 
He effectively conveys the sense of how the good work he thought he was doing in the 1960s — the promise he felt, the sense of hope and forward momentum — is totally lost, and the country’s economy and character have become mired in a lack of ambition, victimization by the world economy, and drained of vitality by the too-close association of neighbors. As a returned Peace Corps Volunteer myself (Mongolia, 1998-99), I found this fascinating. As a traveler to Africa, I found it dispiriting and authentic.
Overall, the book wasn’t as fascinating a journey as some of his other books, and I think that’s because it was a more personal book – a return to one of the formative experiences of his own life, and thus there was a modicum of navel-gazing in Dark Star Safari that I didn’t get from The Great Railway Bazaar or The Happy Isles of Oceania. I don’t feel like I learned much that was ‘exotic’ and interesting about Africa (history, anthropology, geography), but instead the book does an effective job painting a picture of sad stasis and decay, of failed policies and crowded conditions in the cradle of our species.
14 May 2013
An itty bitty brachiopod
Found this small, flat brachiopod fossil last fall just down the road from my place in the Fort Valley. Lovely little thing…
That’s all I’ve got for you today!
13 May 2013
Monday macrobug: Flight of the termites
Termites can fly.
But not all termites.
Around here, the only flying termites are the reproductives – the fertile males and females that a termites colony produces periodically. It seems to be associated with the advent of spring.
I spotted this group a couple of weeks ago, when I noticed the sunlight catching in their diaphanous wings.
They hatch, emerge en masse, and take to the air, seeking a partner of the opposite sex.
It’s a busy scene when they emerge – lots of termites, lots of wing fluttering.
Once they have mated, they jettison their wings, and the female crawls underground (or into a suitable piece of wood?) to inoculate a new colony.
Stay away from my house, termites!
11 May 2013
The latest flood on Passage Creek
We had another flood on Passage Creek on Wednesday, and into Thursday morning. Here are a few photos and GigaPans for those of you who like flood imagery:
Making GigaPans of the scene:
Some images of the flood itself:
Aftermath:
http://www.gigapan.com/gigapans/129490 http://www.gigapan.com/gigapans/129543 http://www.gigapan.com/gigapans/129569
10.3 feet was the maximum gauge height this time (6 is bridge level), which means the stream is putting out 4200 cubic feet of discharge per second.
10 May 2013
Friday fold: New Market / Lincolnshire formation contact, Staunton, Virginia
Happy Friday! Here’s a view of the folded contact between the (older, lower) New Market Formation, and the (younger, upper) Lincolnshire Formation, as exposed in Staunton, Virginia:
The contact has been folded, pretty intensely:
The New Market Formation is massive, light-colored, and exhibits fenestral texture here. The Lincolnshire is darker, more thinly-bedded, and is chock full of fossil invertebrates.
Explore it for yourself in this M.A.G.I.C. GigaPan:
A closer look at the folds is next…
And now, some close-ups showing the fossils in the Lincolnshire Formation:
Mostly bryozoans, as far as I can tell…
9 May 2013
Boudinage in northern Minnesota
This is my final post on the pre-GSA-Minneapolis structural geology field trip to the Superior Province. The photo above shows a roadcut exposure of boudinage in xenolith-bearing Vermillion Granitic Complex.
Here’s another, smaller, more brittle example of boudinage, from another site, the following morning:
Gee, it only took me 1.5 years to blog that trip in its entirety… Sheesh!
8 May 2013
A comparative look at the Klingle Valley outcrop
A week ago, I featured six new GigaPans here, of the extraordinary rocks in Klingle Valley, DC.
I hadn’t been able to get the next phase of imaging that site ready in time for the post, but here it is: an annotated view of the outcrop.
Annotation color code:
PINK = Granite contact
BLUE = Sericite after staurolite pseudomorphs
YELLOW = Outlines of stretched clasts within the metaconglomerate
GREEN = Edges of lichens growing on the surface of the outcrop
Comparative viewer screenshot and link, so you can explore it for yourself:
Pretty cool, eh?
Callan Bentley is an assistant professor of geology at Northern Virginia Community College in Annandale, Virginia. He is particularly interested in structural geology and the evolution of the Appalachian mountain belt. Callan draws cartoons and writes for EARTH magazine. He lives in the Fort Valley of Virginia.
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