Stonefly

This weekend I went camping with my family in Virginia’s Shenandoah Valley, near Berryville. I poked around with river cobbles and experienced fluvial dynamics firsthand with an inner tube ride down the Shenandoah River, but mainly I turned off the geology part of my brain. Instead, the brain enjoyed idling, and thinking about how to throw a frisbee, and listening to bluegrass music, and eating.

The only photos I took were of this lovely stonefly adult (Plecoptera) that landed on my car.

A lovely beast, yes?

Macro Damselfly

I realize the geological blogging has been rather light around these parts lately – just one more day of “fluff” posts… Here’s a damselfly, photographed close-up last Thursday along Route 340 south of Elkton, Virginia.

There were also some rocks there… more on them tomorrow.

Gorgeous poison ivy

Spent the day in the field yesterday with Liz Johnson of James Madison University and her fun group of students in a “Geology of Skyline Drive” summer course. More on the geology later… For now, I just wanted to toss a group of photos of poison ivy up here. Look at this beautiful plant!

Look, but don’t touch!

Mount Taranaki

Searching around for the current Where on Google Earth, I found this astonishing place in western New Zealand:

That’s Mount Taranaki, and evidently the vegetation change you see in the circular colored shape around the mountain must be due to a protected-area boundary. Check out the radial drainage pattern on that sucker!

Check it out yourself here.

Lola and the maps

My cat Lola has a thing for big sheets of paper, particularly maps. Here she is this morning, “helping” me plan a summer trip to Turkey:

Bouquet

In honor of Mother’s Day, I offer up an unusual bouquet of flowers…

These are not really flowers, of course, but an odd form of lichen that I found in the Crazy Mountains of Montana last summer, growing on a spruce tree.

Freaky little things, eh? All shots are with the macro function on: the black circles measure about 0.5cm across. Happy Mother’s Day!

Hand lens + iPhone → Macrocamera

Ever since I saw this at Microecos and Myrmecos, the staff here at “Mountainecos” have been wanting to try it out. Behold my first three iPhone photos supplemented by a hand lens (Belomo triplet, at a distance of about 1.5 cm from the subjects):

That’s a trilobite and a penny, by the way. Try it out; post your results!

“Climate Change and the Integrity of Science”

The following letter, signed by 255 members of the National Academy of Science, appears in the current issue of the journal Science. I wholeheartedly concur with the content of this letter, and republish it here in the interest of getting its message out to the world. Please take the next four minutes of your life to read it. As a responsible citizen of the planet Earth, I encourage you to share this message widely. -CB

We are deeply disturbed by the recent escalation of political assaults on scientists in general and on climate scientists in particular. All citizens should understand some basic scientific facts. There is always some uncertainty associated with scientific conclusions; science never absolutely proves anything. When someone says that society should wait until scientists are absolutely certain before taking any action, it is the same as saying society should never take action. For a problem as potentially catastrophic as climate change, taking no action poses a dangerous risk for our planet.

Scientific conclusions derive from an understanding of basic laws supported by laboratory experiments, observations of nature, and mathematical and computer modeling. Like all human beings, scientists make mistakes, but the scientific process is designed to find and correct them. This process is inherently adversarial—scientists build reputations and gain recognition not only for supporting conventional wisdom, but even more so for demonstrating that the scientific consensus is wrong and that there is a better explanation. That’s what Galileo, Pasteur, Darwin, and Einstein did. But when some conclusions have been thoroughly and deeply tested, questioned, and examined, they gain the status of “well-established theories” and are often spoken of as “facts.”

For instance, there is compelling scientific evidence that our planet is about 4.5 billion years old (the theory of the origin of Earth), that our universe was born from a single event about 14 billion years ago (the Big Bang theory), and that today’s organisms evolved from ones living in the past (the theory of evolution). Even as these are overwhelmingly accepted by the scientific community, fame still awaits anyone who could show these theories to be wrong. Climate change now falls into this category: There is compelling, comprehensive, and consistent objective evidence that humans are changing the climate in ways that threaten our societies and the ecosystems on which we depend.

CREDIT: ISTOCKPHOTO.COM [Larger version of this image]

Many recent assaults on climate science and, more disturbingly, on climate scientists by climate change deniers are typically driven by special interests or dogma, not by an honest effort to provide an alternative theory that credibly satisfies the evidence. The Intergovernmental Panel on Climate Change (IPCC) and other scientific assessments of climate change, which involve thousands of scientists producing massive and comprehensive reports, have, quite expectedly and normally, made some mistakes. When errors are pointed out, they are corrected. But there is nothing remotely identified in the recent events that changes the fundamental conclusions about climate change:

(i) The planet is warming due to increased concentrations of heat-trapping gases in our atmosphere. A snowy winter in Washington does not alter this fact.

(ii) Most of the increase in the concentration of these gases over the last century is due to human activities, especially the burning of fossil fuels and deforestation.

(iii) Natural causes always play a role in changing Earth’s climate, but are now being overwhelmed by human-induced changes.

(iv) Warming the planet will cause many other climatic patterns to change at speeds unprecedented in modern times, including increasing rates of sea-level rise and alterations in the hydrologic cycle. Rising concentrations of carbon dioxide are making the oceans more acidic.

(v) The combination of these complex climate changes threatens coastal communities and cities, our food and water supplies, marine and freshwater ecosystems, forests, high mountain environments, and far more.

Much more can be, and has been, said by the world’s scientific societies, national academies, and individuals, but these conclusions should be enough to indicate why scientists are concerned about what future generations will face from business-as-usual practices. We urge our policy-makers and the public to move forward immediately to address the causes of climate change, including the unrestrained burning of fossil fuels.

We also call for an end to McCarthy-like threats of criminal prosecution against our colleagues based on innuendo and guilt by association, the harassment of scientists by politicians seeking distractions to avoid taking action, and the outright lies being spread about them. Society has two choices: We can ignore the science and hide our heads in the sand and hope we are lucky, or we can act in the public interest to reduce the threat of global climate change quickly and substantively. The good news is that smart and effective actions are possible. But delay must not be an option.

P. H. Gleick,^* R. M. Adams, R. M. Amasino, E. Anders, D. J. Anderson, W. W. Anderson, L. E. Anselin, M. K. Arroyo, B. Asfaw, F. J. Ayala, A. Bax, A. J. Bebbington, G. Bell, M. V. L. Bennett, J. L. Bennetzen, M. R. Berenbaum, O. B. Berlin, P. J. Bjorkman, E. Blackburn, J. E. Blamont, M. R. Botchan, J. S. Boyer, E. A. Boyle, D. Branton, S. P. Briggs, W. R. Briggs, W. J. Brill, R. J. Britten, W. S. Broecker, J. H. Brown, P. O. Brown, A. T. Brunger, J. Cairns, Jr., D. E. Canfield, S. R. Carpenter, J. C. Carrington, A. R. Cashmore, J. C. Castilla, A. Cazenave, F. S. Chapin, III, A. J. Ciechanover, D. E. Clapham, W. C. Clark, R. N. Clayton, M. D. Coe, E. M. Conwell, E. B. Cowling, R. M Cowling, C. S. Cox, R. B. Croteau, D. M. Crothers, P. J. Crutzen, G. C. Daily, G. B. Dalrymple, J. L. Dangl, S. A. Darst, D. R. Davies, M. B. Davis, P. V. de Camilli, C. Dean, R. S. Defries, J. Deisenhofer, D. P. Delmer, E. F. Delong, D. J. Derosier, T. O. Diener, R. Dirzo, J. E. Dixon, M. J. Donoghue, R. F. Doolittle, T. Dunne, P. R. Ehrlich, S. N. Eisenstadt, T. Eisner, K. A. Emanuel, S. W. Englander, W. G. Ernst, P. G. Falkowski, G. Feher, J. A. Ferejohn, A. Fersht, E. H. Fischer, R. Fischer, K. V. Flannery, J. Frank, P. A. Frey, I. Fridovich, C. Frieden, D. J. Futuyma, W. R. Gardner, C. J. R. Garrett, W. Gilbert, R. B. Goldberg, W. H. Goodenough, C. S. Goodman, M. Goodman, P. Greengard, S. Hake, G. Hammel, S. Hanson, S. C. Harrison, S. R. Hart, D. L. Hartl, R. Haselkorn, K. Hawkes, J. M. Hayes, B. Hille, T. Hökfelt, J. S. House, M. Hout, D. M. Hunten, I. A. Izquierdo, A. T. Jagendorf, D. H. Janzen, R. Jeanloz, C. S. Jencks, W. A. Jury, H. R. Kaback, T. Kailath, P. Kay, S. A. Kay, D. Kennedy, A. Kerr, R. C. Kessler, G. S. Khush, S. W. Kieffer, P. V. Kirch, K. Kirk, M. G. Kivelson, J. P. Klinman, A. Klug, L. Knopoff, H. Kornberg, J. E. Kutzbach, J. C. Lagarias, K. Lambeck, A. Landy, C. H. Langmuir, B. A. Larkins, X. T. Le Pichon, R. E. Lenski, E. B. Leopold, S. A. Levin, M. Levitt, G. E. Likens, J. Lippincott-Schwartz, L. Lorand, C. O. Lovejoy, M. Lynch, A. L. Mabogunje, T. F. Malone, S. Manabe, J. Marcus, D. S. Massey, J. C. McWilliams, E. Medina, H. J. Melosh, D. J. Meltzer, C. D. Michener, E. L. Miles, H. A. Mooney, P. B. Moore, F. M. M. Morel, E. S. Mosley-Thompson, B. Moss, W. H. Munk, N. Myers, G. B. Nair, J. Nathans, E. W. Nester, R. A. Nicoll, R. P. Novick, J. F. O’Connell, P. E. Olsen, N. D. Opdyke, G. F. Oster, E. Ostrom, N. R. Pace, R. T. Paine, R. D. Palmiter, J. Pedlosky, G. A. Petsko, G. H. Pettengill, S. G. Philander, D. R. Piperno, T. D. Pollard, P. B. Price, Jr., P. A. Reichard, B. F. Reskin, R. E. Ricklefs, R. L. Rivest, J. D. Roberts, A. K. Romney, M. G. Rossmann, D. W. Russell, W. J. Rutter, J. A. Sabloff, R. Z. Sagdeev, M. D. Sahlins, A. Salmond, J. R. Sanes, R. Schekman, J. Schellnhuber, D. W. Schindler, J. Schmitt, S. H. Schneider, V. L. Schramm, R. R. Sederoff, C. J. Shatz, F. Sherman, R. L. Sidman, K. Sieh, E. L. Simons, B. H. Singer, M. F. Singer, B. Skyrms, N. H. Sleep, B. D. Smith, S. H. Snyder, R. R. Sokal, C. S. Spencer, T. A. Steitz, K. B. Strier, T. C. Südhof, S. S. Taylor, J. Terborgh, D. H. Thomas, L. G. Thompson, R. T. TJian, M. G. Turner, S. Uyeda, J. W. Valentine, J. S. Valentine, J. L. van Etten, K. E. van Holde, M. Vaughan, S. Verba, P. H. von Hippel, D. B. Wake, A. Walker, J. E. Walker, E. B. Watson, P. J. Watson, D. Weigel, S. R. Wessler, M. J. West-Eberhard, T. D. White, W. J. Wilson, R. V. Wolfenden, J. A. Wood, G. M. Woodwell, H. E. Wright, Jr., C. Wu, C. Wunsch, M. L. Zoback

^* To whom correspondence should be addressed. E-mail: petergleick@pacinst.org

“Those aren’t pillows!”

In the 1987 comedy Planes, Trains, and Automobiles, John Candy and Steve Martin have a funny experience. It involves a cozy hotel room (one bed only) and the two travelers are huddled up for warmth. As he wakes up, John Candy thinks he is warming his hand “between two pillows.” At hearing this, Steve Martin’s eyes pop wide open, and he yells, “Those aren’t pillows!”

They jump up, totally discombobulated. An awkward moment follows.

Well, it’s not quite as awkward, but I had a similar “those aren’t pillows” moment recently. I was out in Shenandoah National Park with my GMU structural geology students, and we stopped off at the Little Stony Man parking area (milepost 39.1 on Skyline Drive). Here’s a figure showing the area in question, from Lukert & Mitra (1986):

You’ll note in the detail map at the right that it shows the nonconformable contact that separates the basement complex (here, the “Pedlar” Formation) from the overlying metabasalts of the Catoctin Formation.You’ll also note that it says “PILLOWS” with an arrow pointing at a specific spot on the trail. The word refers to basaltic pillows, which are breadloaf-shaped primary volcanic structures that form when lava erupts underwater. They are typically the size of a bedroom pillow (especially overstuffed pillows). Here’s some video of pillows erupting.

Pillows have been reported elsewhere in the Catoctin (e.g., near Lynchburg, according to Spencer, Bowring, and Bell, 1989), but this is the only location that I’m aware of where they have been reported in northern Virginia. The implications are not all that tremendous: just that a portion of the Catoctin erupted subaqueously, but it would be a neat thing to show students, especially seeing how close the outcrop is to safe parking.

Well, I’ve been to this area a half-dozen times, and I’ve never been able to find those damn pillows. It’s frustrated me, but I had an additional impetus this time around: I ran into Jodie Hayob, the petrology professor from Mary Washington University, who was out there with her students for the day. First thing we said to one another? You guessed it: “Did you find the pillows?”

While the students ate their lunches, I went off downhill (to the west), exploring and looking for these confounded pillows. Pretty soon, I found something that looked vaguely pillowy, at least in terms of have a well-defined “crust” with a dark interior (click through that link for a fine Canadian pillow, courtesy of Ron Schott). Prepare yourself for a lot of photos today… Here’s what I saw:

A few meters further downhill, I found another outcrop of the same stuff, this one veiled in a thin layer of algae (ahh, the joys of east coast geology!):

Little double-ridges which varied in parallel, defining small chunks of rock. Could these be the fabled pillows? But they’re …so small! They’re almost pincushions! I know they say size doesn’t matter, but it’s hard for me to picture a volume of lava this small hitting water and “inflating” to such a puny volume with a nice quenched glassy rind, but then having the interior to stay hot enough to crystallize into basalt. Hmmm. Starting to think something’s fishy with this subaqueous tale…

I then found a nice big cliff, 10 meters high and 20 meters wide, which was made of almost nothing but these structures. Here’s some of them highlighted by the sun (the boundary ridges weather out in high relief), despite being obscured beneath several layers of lichen:

A relatively clean, but relatively unweathered sample:

Aha, now that’s better:

The next two show more of a “classic” Catoctin coloring: chlorite green when fresh, with buff weathered surfaces on the outside:

Zooming in on one small, skinny purported “pillow”:

I climbed back up and coerced some students into joining me to check these weird things out, and they clambered down. Danny W. found a nice chunk of float which showed one of the “pillows” in three dimensions. Check it out at the top of this sample:

Three-dimensional extension courtesy of Photoshop; red line shows the long axis of this oblate ~ellipsoid plunging towards the camera. (Lara laughs in the background…)

Okay; two more… Check out how angular the boundaries of these “pillows” are:

Seeing this one really made me think: No way; “those aren’t pillows!“…

…Seeing that angular “break” on the left led me to realize that not only are these things too small* to be pillows, they also don’t have the right shape. Instead of being “pillowy,” (i.e., round) they are very angular, defined by edges that are aligned in a common direction and continue from one to the next.

* Where “too small” is defined as “smaller than anything Callan has seen before.”

I sketched in some of these planar edges:

To me, it looks like what’s happening here is that original homogeneous rock of the Catoctin Formation fractured, and then fluids flowed along those fractures, altering the rock that the fluids came into direct contact with. This produced the “double ridge” of buff-colored rock (on either side of the fracture), with the less-altered greenstone interiors being beyond the reach of these altering fluids. The intersection of the various joints and their subsequent boundary-defining alteration would look something like this example (from the online structure photo collection of Ben van der Pluijm): definitely click through to check it out.

In other words, I interpret these structures to be secondary, not primary. The end result is something that looks a lot like “boxwork” (again, please click through to get a sense of what I’m suggesting here): a phenomenon that occurs when limestone fractures, more resistant mineral deposits are precipitated in those fractures, and then the limestone blocks are dissolved away, leaving behind the “fractures” as planar ridges separating little “boxes” from one another.

Here’s two photos of boxwork, one whole-sample, one zoomed-in. This sample is in the USGS library in Reston, Virginia, and both photos were taken at my request by Bill Burton of the Survey. (Thanks Bill!)

At Little Stony Man, of course, the greenstone hasn’t “dissolved” away, but it does appear to be weathering more rapidly than the resistant buff-colored edges to these blocks, producing a distinctly boxwork-like effect.

Let’s look back at some of my field photos again, this time with the pillow boundaries highlighted in red…

(…I definitely could have hit a few more boundaries on that last one; forgive me for being haphazard and slapdash…)

This exercise convinced me that these things are not pillows, but some sort of fluid-rock interaction effect that took place on a complex fracture network. There’s no reason for the sharp edges of two adjacent pillows to be perfectly parallel and aligned.And it strains credulity to imagine ultra-tiny pillows in the first place (the size of my fingernail? Come on!).

I’ve e-mailed one of the authors of the original paper claiming pillows in this area with a link to my photos asking if these things are what he and his co-author were referring to, but I haven’t heard back anything. (I’ll update this post if he responds.) I might be totally off base here, but I can see how someone could make the claim that these were pillows. It’s just not a claim that convinces me, based on these outcrops.

What do you think? Do these look like any pillows you’ve ever seen?

__________________________________________

References:

M.L. Lukert and G. Mitra (1986). “Extrusional environments of part of the Catoctin Formation.” Trip #45 in Geological Society of America Centennial Field Guide – Southeastern Section, pp.207-208.

E.W. Spencer, C. Bowring, and J.D. Bell (1989). “Pillow lavas in the Catoctin Formation of Central Virginia.” in Contributions to Virginia geology, volume VI. Virginia Division of Mineral Resources publication 88, pp. 83-91.

Hackles, ribs, plumes

Today, you get a photo from GMU structure student Nik D. This is a small exposure in the Hampshire Formation (Devonian) on New Route 55 in West Virginia. It shows a fine example of plumose structure with the not-often-seen concentric ribs running perpendicular to the ‘plumes.’ At the edge of the joint, you can see the flaring fringe of hackles. Top edge of a Rite-In-The-Rain field notebook for scale:

Where shall we zoom in? How about these two boxes?

Close-up of the concentric ribs:

Close-up of the hackle fringe on the edge of the joint:

…Even the hackles have hackles!

Good stuff: I love me some fine plumose structure!