So that's how it works... (from the Onion.)

Labels: birdies, evolution, humor

As a high school student in Arlington County, Virginia, I used to take regular hikes down a path called Windy Run, and then walk along the south shore of the Potomac River, upstream. It was in the days before I knew anything about rocks, and I was mainly appreciating other aspects of nature, like the plant life, the birds, the bugs, the salamanders, and occasionally something really cool like a raccoon. But I was aware that the scene I observed and enjoyed was not the same scene that had always persisted.

I heard rumors from my uncle about patches of woods inside the DC Beltway that preserved virgin forest -- giant trees that gave a hint of the former majesty of this eastern hardwood forest. I read about an eastern herd of bison that would migrate north and south through the Piedmont and Coastal Plain, crossing the Potomac near Alexandria (before we killed them all). I noticed a gazillion deer, and had it explained to me that the lack of predators like cougars and wolves resulted in the herbivores' population explosion. We used to have elk here, but European colonists had extirpated them. The last of the bison were killed off by 1800, and the final elk met a bullet around 1850. This used to be a pretty wild place!

I observed trash nearly constantly, often mixed obscenely with natural debris, sheathed in mud, or woven into birds' nests. Every few minutes, a jet airplane on its approach to National Airport would thunder overhead. Those of us who lived in the flight path would learn to automatically put conversations on "pause" during the 30 seconds it took for the planes to pass. Visitors didn't know what to do about the noise; it was too pervasive to be ignored. But live here long enough, and you learned to ignore it. You adapted, like the birds adapted by putting aluminum foil and plastic bags into their nests.

And the river itself? It's gross. In the modern day, it's constantly muddy and silty, with a foul-smelling sewage/sediment biofilm all over the rocks and logs in the water. There's scummy flotsam and rumors that you'll get a rash if you swim in it. There's people fishing down by Teddy Roosevelt Island, and you have to wonder why... They're not going to eat the fish they catch out of this polluted stream, are they?

The theme of this month's Accretionary Wedge is "time warp." The Wedge is a geoblog 'carnival,' though it's been inactive for a while, this month sees its return to 'accreting.' For those of you who are new readers to NOVA Geoblog, it's probably a great opportunity to check out some of the dozens of other interesting geoblogs out there. So what does this have to do with my reflections on the local woods, and the Potomac River? This month's Wedge host is Lockwood from Outside the Interzone. He asked geobloggers, "Where and when would you most like to visit to witness and analyze an event in Earth's history?"

I'm going to use my time travel experience to go back in time right here, in Washington, DC. I want to go back to 1491*. I want to see what my home looked like before European settlers showed up and brought their particular brand of industrialization / civilization / land use changes / ecological perturbations to the Potomac River valley. It may surprise readers to learn that I'd opt for this -- a simple experience of pre-colonization North American nature -- over something tectonic and structural, but that's what calls to me on a deep, emotional level. I want to see a vibrant ecosystem with big trees. I want to see the water of the Potomac River look like water; I want to go swimming in it. I want to see what bird migration looked like before it dropped off so precipitously. I want to see a passenger pigeon, a carolina parakeet. I want to see for myself what a healthy amphibian population looks like. And bison fording the Potomac in Alexandria... perhaps emerging from the clear water with the autumn colors ablaze on the far side of the river? That would just be... awesome.

* Note that there's a good book by this same name, on this same theme, 1491. The book makes the case that there was already a lot of landscape/ecological modification playing out before Europeans arrived: that native Americans played a significant role in messing with natural systems and we shouldn't imagine an ecological paradise, just less of an ecological disaster.

Of course, going back to 1491 may have some negative aspects to it: there would be malaria endemic to DC at that time, and the native tribes might not take kindly to a time traveler popping in to ogle their forested homes. But I'll take those risks (they exist today in other places I've visited), since the pay-off would be such a profound deepening of perspective.

If I had the ability to go back in time, I'd use it to gain experience with pre-colonial North America. I'd check out the same river banks I would walk 500+ years later, and see what we've lost.

...And, once I've seen that former world, I can't guarantee that I'd come back.

Labels: amphibians, birdies, blogs, dc, environmental, geologic time, mammals, piedmont, rivers, virginia

That's a black-crowned night heron I saw on a little post-coffee, pre-work walk in Rock Creek Park the other day.

Labels: birdies, dc

A shot from DC's Tidal Basin this weekend:

Labels: birdies, dc, plants

Ladies and gentlemen, spring has arrived in the Washington, DC region. It is sublime. I'm very grateful that it's my spring break this week because even though I still have a ton of work to do, I've had the opportunity to get outside every day and enjoy a bit of the weather.

This weekend, I got up early both days and headed out the the Billy Goat Trail, a rugged hiking trail along the Potomac River's gorge about 12 miles upstream from DC. I departed from the trail itself both days, which was great because it brought me to places I hadn't seen before. I found a lot of cool new structures and rocks! Over the next few days or weeks, I'll be sharing some of those images with you, but for today, I figured I'd show you some 'soft' imagery, just to celebrate the fun of being outside on a hike on a lovely day. ...and wearing short sleeves, no less!

Here's a shot of typical scenery along the Billy Goat Trail. This is looking upstream:



One of my side-trips off the trail... because the water level was pretty low, I was able to get to some islands that are often inaccessible. This is the channel between the Rocky Islands (downstream of Great Falls, upstream of Mather Gorge):



This land is all part of the C&O Canal National Historical Park. Here's a spot where rains from Tropical Storm Hanna breached the wall of the C&O Canal, allowing its water to drain downward into the Potomac. Because the canal's towpath was located there, the Park Service has constructed a temporary path which detours around the breach:



I saw some good birds on my hikes there. Red-tailed hawks, double-crested cormorants, Canada geese, mallards, belted kingfishers, pileated woodpeckers, red-bellied woodpeckers, tufted titmice, chickadees, robins, blue jays, and great blue herons. Also, both local species of vultures: the turkey vulture and the black vulture. This is a black vulture (note the black, not red, head):



Here's some tracks: theropod dinosaurs? ...or great blue heron? You be the judge:



Here's a cool fish skull I found:



Of course, it wasn't all scenery, birds, and fish. There were rocks, too. I took a lot of rock photos, and you'll get to see them all in due course... But for now, let me start you off with the tame stuff. Here's some cobbles I encountered along the hike...

Cobble of the Seneca Sandstone (Triassic arkose) showing a mudchip rip-up clast:



Tilting it a bit, you can see other mudchips too:



Cobble of cement containing Seneca chunks:



Cobbles of quartzite of the Antietam Formation showing Skolithos 'worm' tube trace fossils:



I love these Skolithos tubes. It's hard not to love them, and they're everywhere around here. Like the Seneca cobbles, they come from source areas to the west (Culpeper Basin & Blue Ridge, respectively), and were transported to the Maryland Piedmont by the ancestral Potomac River.



My favorite Skolithos-bearing quartzite cobble:



...And the same cobble, end-on:



More to come, tomorrow...

Labels: birdies, blue ridge, culpeper basin, fish, fossils, maryland, national parks, piedmont, sediment

Coyote Crossing alerted me to this awesome-looking application for the iPhone: a field guide to the birds of North America. On my way back home to the apartment last night, I parked my car in Mt. Pleasant and was walking up the hill to my building, when I saw two of my neighbors pointing a flashlight into the woods (yes, we have woods in DC). "What have you got?" I asked. It was an owl, and they obligingly pointed it out to me. I identified it as a barred owl, and explained the field marks that would allow them to distinguish it from our other big eastern owl, the great horned owl. As we talked, the barred owl flushed and silently swooped through the tree branches and into the darkness. Anyhow, if my neighbors had the iBird Explorer Plus, they wouldn't have needed to rely on an ex-ornithologist walking by at that moment. Pretty cool!

Labels: birdies, dc, gear, tech

I went to Ecuador to climb mountains.

After a lovely two days of recovery in the thermal springs of Papallacta, Lily and I began our mountain-climbing tour. We summited three peaks in the central Ecuadorian Andes: Pasochoa, Ruminahui, and Iliniza Norte. Today I'd like to share our experiences climbing the first (and shortest) of those, the peak called Pasochoa. Here it is from the rough road we drove in on:



From a Google Maps perspective, here's the physiography of the surrounding area. Pasochoa is the highest peak of the central volcano in this view:



Once we started hiking, we got above the trees and into the paramo ecosystem, a high-elevation grassland biome that exists between treeline and the bare rocks above where only lichens survive. Another view of the peak, which is about 13,700 feet in elevation:



Once we got up a little bit, we could look down to the Valle de los Chillos, a massive valley between Andean peaks, south of Quito:



One of the most spectacular things that happened on this hike is we saw an Andean condor, which flew by between us and this view, quite spectacularly. We weren't able to get the camera out in time to capture it, but with its black and white plumage, it was unmistakeable. Here's a amateurish Photoshop to show what it kind of looked like:



I pointed out the volcanic breccia to Lily and our guide, Diego:



More of the same could be seen in eroded-out minarets on the flanks of the mountain:




Pasochoa is one tall bit along the rim of a much larger caldera, and when we got up to the edge of that caldera, we got a real sense of its sudden drop-off. Clouds/fog curled up and over the lip, obscuring the view, but we could peer down into them and see that the land dropped steeply away for many hundreds of feet.



Lily gives a sense of scale to the edge of the caldera:



After lunch on top, more clouds moved in, and we decided to decamp back to the vehicle. Here's Diego and I descending the trail towards lower elevations.



Being a guy who had just recently recovered from something akin to pneumonia, I felt pretty good about making the summit of a 13,700' peak. Next up: let's see if we can't find something a little bit taller...

Labels: birdies, ecuador, mountains, south america, travel, volcano

You know what feels really good when you're feeling sick? A hot bath.

And so, when it came to pass that over the winter break, I flew down to Ecuador with a recovering case of pneumonia, my friend Lily and I opted to put our mountain-climbing plans on hold, and go sit in some hot water instead.



From Quito, we took a public bus ($2) an hour east to a series of thermal pools at Papallacta ("papa yacht uh"). This is a lovely resort, nestled in a lovely valley:



Inside the resort (>$2), the architecture was fused with the landscaping in some interesting pseudo-natural ways. For instance, this is in the lounge, where the rocky wall rises up, but then stops some distance below where the wooden ceiling begins. The interval is filled with glass, but the illusion is that the building is open to nature.



They've got nice grounds, too. An organic garden is featured, and they have some neat sculptures. This one is clearly inspired by Andy Goldsworthy.



But there was a mystery... The local river, which carved the valley, was cold:



...So where did the hot water come from? We had noticed some steaming pools on the bus ride over the Andes, at higher elevation. Taking a walk on our second day there, we saw this aqueduct coming down the mountain into the valley:



Aha! It must be that they are pulling the hot water out of the actual hot springs up above, then piping it down to Papallacta for people to enjoy.

Papallacta is just south of the Equator:



At the Equator, Papallacta's elevation of ~10,000 feet (~3300 m) is quite pleasant. A tad chilly when it's dark or overcast, but the snow was at a higher elevation still:



Hiking around in between soaks in the lovely hot water, we saw hummingbirds galore, including the bizarre sword-billed hummingbird, which has a beak longer than its body (Google it to see!) We also saw some cool critters, like this beetle:



...And also some cool plants. Lily's really into plants, but even I can appreciate their numerous and varied forms, especially in as biodiverse a place as Ecuador...



Flower-on-a-stem, within a leaf:



After soaking and resting and acclimatizing at Papallacta, I felt a lot better and we trooped back to Quito to meet up with our guide and start climbing mountains... More on that in posts to come.

Labels: art, arthropods, birdies, critters, ecuador, hot springs, plants, south america, travel

Due to a scheduling mishap, this semester I'll be teaching my Environmental Geology lab in the new Science Learning Center in the Schuler Building on NOVA's Annandale campus.

This past Thursday night was our first session in there. Exploring the new facility, I opened up an old-looking refrigerator back in one corner. "What's in here?" I wondered....



Whoa! A bunch of dead birds! These are, no doubt roadkill (or window-kill) samples that are awaiting preparation as 'study skins.' Under professor Walt Bulmer, NOVA has developed a robust collection of study skins to aid in ornithological studies. (I'll have to shoot some photos of those sometime.)

Though I hadn't expected to see a pile of dead birds in the fridge, I soon recovered from the shock. Before converting to geology, I used to study ornithology, and have spent time prepping study skins in the lab at William & Mary (and once, in my dad's basement, with a Sturnus vulgaris that turned out kind of stinky). Returning to my students working on their lab, passing the anatomical models and the physics references, I thought how refreshing it was to be working in a lab utilized by all the sciences.

I guess in retrospect, I should have suspected the fridge's contents when I saw this cartoon taped to the front of the fridge door:

Labels: birdies, humor, nova, teaching

Recently, Andrew Alden compiled a list of state minerals and state rocks. A quirky piece in today's Washington Post explores what Maryland is urging its citizens to do with their state fish: eat them. The story also, somewhat randomly, includes a limerick composed by Virginia's former governor and current senator, Mark Warner:

We have a state dog and a fish and a bird.
And of the fossil I'm sure you have heard.
So why not a bat?
What's wrong with that?
The state beverage is no more absurd.

For some reason, I hear this limerick in my head in Carl Kasell's voice...

Labels: birdies, critters, fish, fossils, mammals, maryland, politics, virginia

What's the tallest mountain on Earth?

Everest, right? Well, yeah: if you're measuring from sea level. If you're measuring from the top of the crust the mountain rises from though, it's Mauna Kea, Hawai'i. It's about ~13,800 feet above sea level, but it rises ~33,500 feet from the oceanic crust to the peak (that's compared to Everest's mere ~29,000 feet from base to peak. So... you could say that Mauna Kea is the tallest mountain on our planet... (you could!)

On Thanksgiving day, my friend Lily and I took a drive up to the top of Mauna Kea, and did a little hike up there at high elevation. Today, I'd like to share some photographs of that excursion. We saw some pretty cool geology.

On the drive up the mountain, we saw an animal which was apropos, considering the day:

Gobble, gobble, gobble. Watch out turkeys, we'll be back after we work up an appetite...

Here's Lily's jeep in the "saddle" between Mauna Kea and Mauna Loa, looking north (with Mauna Kea in the background and basaltic lava flows from Mauna Loa in the foreground):


Some cider cones (the Hawai'ian word for cinder cone is pu'u) in the saddle:


Turning the other way (looking south), you can see the bulky form of "the long mountain," Mauna Loa. What a classic shield volcano shape! I love the fact that it's so dang wide it makes a lousy photograph. You just can't capture its spread-out bulk in a photo; it's too massive:


This was the spot where I pretended to have my toes overrun by a pahoehoe flow:


As we drove up the road to the top of the mountain, I was amazed at the raw volcanic landscape, decorated with cinder cones like this one:


At one point, we passed a neat little angular unconformity on the roadside. Here it is, with a nickel (white dot left of center) for scale:


Here's a closer-shot of this small angular unconformity. Earlier layers of ash and lapilli were deposited at a steep angle, and then eroded (perhaps by glaciation? pure speculation there) before more ash and lapilli were deposited atop it, at a lower angle. There's not likely to be much time missing here, and so perhaps it's better to think of this as the top of a cross-bed, an advancing front of pyroclastic deposition moving down the mountainside, overrun by later eruptions, which may have scoured off the upper few inches (??? pure speculation) or so before deposition.

Really, the truncated tops of cross-beds are mini-angular-unconformities, when you think about it; just not with the same amount of time missing at a "real" angular unconformity (with millions of years missing) due to mountain building like the one at Siccar Point. (Video of cross-beds forming)

Here's something else which the clueless geologist might mistake for a sign of mountain building:
No, those aren't originally-horizontal strata that have later been folded. They're layers (again of ash and lapilli) deposited on the originally-rough topography of the mountainside, covering small ridges and filling small valleys. Where a given layer is exposed at higher elevation, I interpret to be a paleo-topographic high; where that same stratum is exposed at lower elevation, that's a paleo-topographic low. The roadcut reveals these layers have undulating shapes, but this is unlikely to be folding that results from tectonic compression: instead, I think it's showing us the lay of the ancient land surface.

Looking south, we could see past Mauna Loa to the actively erupting steam vent coming out of Halemaumau Crater at Kilauea Caldera (source of the vog!):


Near the summit of Mauna Kea, there are a bunch of astronomical observatories:






On the summit is where you find those examples I mentioned the other day of hawaiite, a rock of basaltic composition that is very dense (ostensibly due to erupting beneath the extra pressures of a Pleistocene ice cap):


Here's me on the summit:


View to the north from the summit: More cinder cones...


Here's a YouTube video of me pointing stuff out from the summit (Kilauea, Hualalai, Mauna Loa, observatories, hikers, etc.). Unfortunately the wind makes it all but unintelligable, but I filmed it, doggone it, so I'm going to post it:



I found a beautiful example of a volcanic bomb up there:


After the visit to the summit, we went for a hike to a small supposedly-glacially-gouged-out lake below the summit (Lake Waiau):


Here's a Google Map, showing the lake's location:


I was surprised to see a thick biofilm on the bottom of the lake:


Encrusting the pebbles and cobbles there, it reminded me of Nora Noffke's modern and Archean biofilm photos in the recent GSA Today, as well as my "Life in Extreme Environments" class this past summer at Montana State University.


We saw some nice examples of structural geology on this hike. Previously, I've mentioned plumose structure, a branching pattern on the topography of fracture surfaces in fine-grained rocks. We saw some of that on blocks of basalt atop Mauna Kea, as in this example (again a repeat photo, but the other day I showed it to you for the vesicle; today I'm showing it to you for the plumose structure.)


A similar feature are arrest lines, which again are minute variations in the surface of a fracture. Like plumose structure, which branches from a source point (where the fracture initiated) and branches out in the direction of propagation, arrest lines tell us about the development of a joint. Unlike plumose structure, though, they are not parallel to the propagating fracture front. Instead, they form perpendicular to it, and record how the fracture propagates in small "steps." Each of these arrest lines is interpreted as being a spot where the fracture grew a little bit, then stopped ("arrested") and then grew some more. In this case, the fracture face we're looking at started at the bottom of the picture and grew towards the top of the photo. You can even see some less-discernible plumose structure backing this up:

Similar arrest lines can be seen in basalt images here and here...

We also saw some pretty spectacular xenoliths. Here's one of gabbro in basalt:


Here's one of peridotite in basalt:


And a few more:



My boots, with another volcanic bomb:


Driving back down the mountain afterwards, we got this nice view of the cinder cones (pu'us!) in the eastern part of the "saddle" between Maunas Kea and Loa:


This Mauna Kea excursion was one of my favorite things that I did on my all-too-brief trip to Hawaii. It was great to get up in the high country, where the air is thin (and vog free!) and the skies are deep blue, and the geology is surprisingly varied (at least it was surprising to me, and pleasantly so). The hike let us work up a good appetite, so we headed back down the mountain and straight to Thanksgiving dinner!

Labels: basalt, birdies, geology, glacial landforms, hawaii, igneous, mountains, msse, primary structures, structure, travel, unconformities, volcano, xenoliths

Yesterday, I took a three Honors students and a colleague to Difficult Run, Virginia. This is a hiking trail that goes from Georgetown Pike, in the tony neighborhood of McLean, Virginia, down through a deep, steep river valley to the Potomac River.

As noted a couple days ago, the trail is right across the Potomac River from my beloved Billy Goat Trail. In a recap from that post, here's a map of the area... Feel free to switch it to "satellite" view.



Some discussion of the bedrock geology of Difficult Run can be found here, in an excellent field trip guide by Scott Southworth (USGS) and colleagues that's part of Excursions in Geology and History (Frank Pazzaglia, editor).

We began our trip by meeting up with Doug Dupin of the Palisades Museum of Prehistory, who joined us for our exploratory geohike. We walked a short distance down the trail and found a big (abandoned) quarry where it was rumored there was a good fault. This is one of these pieces of information that I heard somewhere, at some point. I couldn't find it in any literature, so maybe I heard it in discussion when I taught at George Mason University for a year between grad school and when I got my position at NOVA. Anyhow, I had never actually checked it out...

...So our first order of business was to review the criteria for identifying a fault: What would we look for? Fault breccia, fault gouge, slickensides, hydrous mineral veins, and of course, offset. However, here in the Virginia Piedmont, it's rare to have a good marker unit to compare on opposite sides of the fault: usually it's just schist on one side, schist on the other. In some places, you could add the presence of a fault scarp to that list, but being as how this was an old quarry, geomorphic features like that didn't seem likely. So our search focused on the search for fault breccia, fault gouge, veins of odd minerals, and slickensides.

A few minutes in, we found some slickensides on this boulder of float:

This is a boulder of migmatitic phyllonite, with a wavy texture due to mylonitic flow at depth. (The picture doesn't show this very well at all, though you can see faint undulations 'cascading' from the top of the photo towards the bottom. It's much clearer in cross-section.) Anyhow, the 'slicks' are a faint upper-left to lower-right lineation seen on this surface, one or two degrees off from the orientation of the ballpoint pen. The surface you're looking at here was a fault plane at some point in its history. Ballpoint pen for scale.

We did eventually locate the fault, uphill from this boulder. It was characterized by a zone of fault gouge (pulverized rock), three inches wide to a foot wide in places, and highly oxidized (presumably by oxygen-rich meteoric waters percolating along this fractured surface)... but there were no good marker units to judge the total offset.

Here's a different section through a similar rock (though I wouldn't apply the "phyllonite" textural description to this one). Instead of looking at the plane of foliation here, we're looking at a surface which is perpendicular to the foliation plane(s)....

Here in this image, you can see two cleavages... One which runs roughly upper-left to lower-right through the photo, defined by gneissic banding including bands of granite (light-colored; late Ordovician in age... Taconian Orogeny). A second cleavage runs roughly left-to-right through this photo. This second cleavage overprints the first. The overall interpretation is that the first cleavage developed due to lower-left-to-upper-right compression, forming the foliation defined by alternating bands of different compositions of minerals in an upper-left to lower-right direction. The second cleavage formed due to compressive stress sub-parallel to the pre-existing foliation, deforming it into a series of tight folds. The limbs of these folds line up parallel to one another, defining the second-generation, overprinting cleavage. Can anyone else add to this interpretation? Dime for scale.

Along Difficult Run itself, the outcrops were all relatively recently scoured (in 1972 by Hurricane Agnes), so there are some good exposures. As I noted earlier this week, the area shows some nice exposures of granite pegmatites (keys, and the edge of the Pazzaglia volume, for scale):


On our field trip yesterday, we took at closer look at these beautiful pegmatites, and the associated amphibolite bodies. Take a look at this close-up... Dime for scale.

What's going on here? You've got a beautiful (euhedral/subhedral) example of an orthoclase feldspar ("potassium feldspar") crystal amid a bunch of quartz. But look closer at the feldspar crystal... this sucker has been fractured in many places, and it's shot through with very small veins of quartz. Somehow, as this pegmatite dike was cooling, the earlier-crystallizing feldspar was broken and intruded by the presumably-still-fluid silica-rich magma. Anybody able to expand on this interpretation and shed some light on how this all played out? Or contradict it and give a different story to explain this relationship?

In the neighboring amphibolite, we checked out these cool ridges of resistant rock which are centered on thin fractures. Here, you see a couple of intersecting joint sets, each of which was the "plumbing system" for silica-rich hydrothermal fluids (my interpretation). These silica-rich hydrothermal fluids impregnated the surrounding amphibolite with quartz, which made the immediately-adjacent areas more silica-rich, and hence more resistant to weathering and erosion: Hence, now that they've made it to the surface, they're weathering out in high-relief. Dime for scale.


A bit further downstream, Doug showed us a 'cave' (central dark area, just to the right of the waterfall) between the bedrock and a big slab of sloughed-off migmatitic metagraywacke:

We each edged into the 'cave' to the end, where Doug has shown that a distinctly-rectangularly shaped hole admits a direct beam of sunlight during the fall and spring equinoxes. From the inside, it's a striking arrangement, enough to make you wonder whether it's anthropogenic. However, from the outside I was unconvinced that the hole's position was anything other than natural. Doug's initial intepretation of the site was strongly influenced by the fact that there are some unambiguous petroglyphs a short distance away from here, and based on this proximity, I think it's acceptable to infer that Native Americans may have visited this cave. However, I interpreted the opening to be completely natural, with no need to invoke anthropogenic modification in any way.

We hiked on along a ridge overlooking Mather Gorge, sighting a fox and an accipiter (Coopers? Sharp-shinned?) and a few vultures, and returned to the parking lot as the sun dipped low in the sky. On the way back to campus, Honors students Ana and Hope fed us Swiss cookies and cheese & crackers. Altogether, it was a pretty great way to spend a November afternoon...

Labels: birdies, faults, field trips, granite, igneous, metamorphism, ordovician, piedmont, rivers, virginia

On Saturday, June 14, I drove from Fort Collins, Colorado northwest across Wyoming, ending up just west of Cody in Shoshone Canyon.

Here's a few photos I took along the way:

Hogbacks (or "incipient hogbacks?") north of the Interstate (not sure whether this qualifies as the Laramie Mountains or the Medicine Bow Range, or some other range altogether).

Regardless, what you're seeing here is what happens when tilted sedimentary strata are incised by streams. The stream valleys develop at regular intervals along the slope, and notch the sedimentary layers, which themselves have different resistances to erosion. As a result, these triangular-shaped slabs end up poking up along the flanks of the mountains (the Flatirons outside of Boulder, Colorado, are perhaps the best known example).

The Wind River Range appears in the distance. Seeing big bad mountains makes me happy.


Road trip man!


The Prius at the southern (upstream) end of Wind River Canyon, between Shoshoni and Thermopolis:


...And looking downstream (north):


Unconformity between Archean basement rocks and overlying Cambrian sandstone:


The Wind River:


An outcrop on the way north, somewhere south of Meeteetse. Got some cool green concretions here, and coasted downhill for more than ten miles:


Camp at the end of the day. This is at Buffalo Bill State Park, between Cody and the eastern entrance to Yellowstone (Sylvan Pass, subject of a photo I put up yesterday). The body of water seen here is the Shoshone Reservoir. I enjoyed a pleasant evening here of drinking wine, writing a letter, and watching grebes in the water.


Dark clouds came over later, hastening nightfall over the park. Note the addition of the rainfly to the tent. Turns out we just got a sprinkle, no real downpour.


Life on the road is (was) good. Months later, it makes me happy to look at these photos and think about rolling along across the great North American continent, checking stuff out, seeing new places. Classes start on Monday for me, and I'll be locked down in DC for a bit... a fair trade, it seems to me, if my job allows me to go out and see places like these during the summers.

Labels: birdies, travel, wyoming

I left Bozeman on Saturday morning, and drove for about seven hours. I headed south through Ennis, Montana, along the western side of the Madison Range, passing by the Madison Earthquake Site landslide (from the 1959 Hebgen Lake earthquake), and then south into Idaho. I went through Island Park, Idaho, site of the caldera of one of the three big recent eruptions of the Yellowstone volcanic center. Then into northern Utah, where I got a glimpse of the Great Salt Lake. I headed up into the Wasatch Range to spend the night, just east (and several thousand feet above) Ogden, Utah. I did some birding on the reservoir there, observing the mating rituals of both the woodcock (amazing humming noise produced during flying dives) and the western grebe (neck bobbing following by synchrnonous running across the water).

The next morning, I headed west from there, into the basin, across a range, into another basin, across another range -- you get the idea. I initially intended to go hunt for trilobite fossils in the Wheeler Shale in the House Range, but the 20-mile dirt road rattled me (quite literally) and I turned around after only four miles. I got spooked: what would happen to me if the Prius broke down out here? It's really quite desolate country. I've only ever had that feeling once before, when my Dad and I drove across the Namib Desert. It's a mix of agoraphobia and anxiety over feeling inept at repairing mechanical things, like Prii and other automobiles. I chickened out -- no trilobites for me. But there was a consolation in Great Basin National Park, which was where I headed that afternoon. I did a short hike there in the Snake Range, and toured Lehman Caverns there (my third guided cave tour in two weeks!). I had my best campsite of the trip at Great Basin: montane forest, with a gurgling stream running fifteen feet from my tent. Lovely.

When I woke up, I packed up the car and coasted downhill for eight miles into the town of Baker, Nevada, where I had a great breakfast and coffee at a little cafe there. Then up and over the Snake Range, and down the next valley to the west, south for 93 miles of some of the most empty country I've ever seen in America. In an hour and a half of driving, I saw only 20 vehicles. I crossed back into Utah, and then made my way south to the edge of the Colorado Plateau, and drove up into Zion National Park. Zion is a great canyon cut into a series of sedimentary rocks. The last time I was here, 13 years ago, I walked up the Narrows, and my first order of business was to repeat that hike. There's a new shuttle system in the park now, so after parking at my campsite, I hopped on a shuttle into the park and rode it to the end. I waded into the Virgin River and shuffled upstream. In the Narrows, the Virgin River has cut down through the Navajo Sandstone, but not quite down into the weaker underlying Kayenta Formation, and so the canyon is deep but narrow. (Downstream, when it gets deep enough to tap into the Kayenta, it undermines the sandstone cliffs, and the valley widens.) "Hiking" here is one of the more unique outdoor experiences I've had. Being immersed in the cool river, surrounded by towering rock walls -- it's magical. The further upriver you hike, the less people there are, and it's like a cathedral. I went up and around several entrenched meanders, and marvelled at the alcoves, cross-bedding, and variety of cobbles in the riverbed.

Today, I'm staying in the park and heading up to Angel's Landing, a legendary hike in its own right. Tomorrow morning, bright and early, I'm off to Las Vegas to pick up my Dad and brothers for our Grand Canyon rafting trip. Not sure if I'll be able to post again until after I get out.... late next week.

Labels: birdies, fossils, grand canyon, idaho, montana, national parks, stratigraphy, travel, utah

There's been some interesting articles in my media subscriptions lately. Thought I'd use today's post to share.

In the June National Geographic, a study of the geology of Stonehenge reveals the source of the monoliths ("polyliths?") there. They came from the Preseli Mountains of Wales. That's a long journey for such big rocks. Also in the same issue is an eye-popping pictorial piece on sea slugs. You must check it out, because it features dozens of David Doubilet images like this one:

WIRED's cover story this month is about environmental "heresies": ideas that supposedly environmentalists aren't supposed to like, but need to happen. The basic premise is that "only cutting carbon matters," and so they come up with some interesting recommendations like: (1) use A/C more, and heating less, (2) "screw the spotted owl" (don't worry about the loss of biodiversity), and (3) buy a used Geo Metro rather than a new Prius. I found this last of particular interest, as it recounts a web rumor that it took less carbon to make a Hummer than a Prius, and therefore Hummers were more environmentally friendly. (The Prius' battery has a lot of high-carbon-cost nickel in it.) WIRED breaks it all down into BTUs, and runs the numbers. According to their analysis, it takes the Prius 100,000 miles to catch up (i.e. be more carbon-efficient) than an old Toyota. Bummer... Big bummer. (At least the Hummer bit has been debunked.)

As usual, Smithsonian had a bunch of interesting pieces in it. Almost everything in there catches my imagination. It's a very well done magazine.

The New Yorker had a couple of articles, too: In their recent "innovators issue," Alex Ross profiled John Luther Adams, the man responsible for the mesmerizing "the place where you go to listen" in the Museum of the North at the University of Alaska, Fairbanks. If you haven't ever been there and find yourself in Fairbanks, I would recommend this museum highly, and this one room / art installation in particular: it plays certain notes and tones and changes the lighting depending on what the aurora, seismic activity, and other Earth processes are doing. And Margaret Talbot profiled Irene Pepperberg, who raised the parrot Alex and taught him to talk. This article explores the insights into intelligence gained from this serendipitous longterm experiment.

On the commodities front, the New York Times reports today that thieving biofuellers are stealing vegetable oil in Oregon, and that guano stocks are being closely guarded in Peru. Telling quote from the latter: "Before there was oil, there was guano, so of course we fought wars over it," (Pablo Arriola).

Labels: alaska, birdies, environmental, mollusks, news, prius, wales

Okay, so we've all heard what a stinker the new movie 10,000 B.C. is, right? I actually went to see it, on Geotimes' nickel, along with a couple of other scientists so we could assess the scientific validity of the film for the magazine. Afterwards, I went to enter my own "review" into Netflix (2 stars out of 5) and I noticed there was another "10,000 B.C." film in the Netflix library: "L.A. 10,000 B.C.," a program from the Discovery Channel that examined the natural history of the Los Angeles area during that same time. I decided to check it out, and last night I watched it.

My brief review: It's not really a traditional natural history program. Instead it takes fossil evidence and uses it as a starting point for a "reality T.V." style stunt program. They take three L.A. stunt actors and "train" them to be Ice Age hunter-gatherers. Then they build pneumatic robots to mimic the teratorn and Columbian mammoth, and the stuntmen and women have to battle them. No joke. This resulted in some cool visuals, though: the mammoth crushing a ten-pound can of tomatoes and having all that red spray everywhere (mimicking the head of a Clovis hunter). And the footage of the stuntman being tossed thirty feet through the air by the "angry" robot mammoth was kind of cool too.

But you can't really call that a nature program. There were some cool facts presented, but the majority of the film was devoted to sensationalism of the encounters between humans and these Pleistocene species. The film was also very repetitive, taking half an hour's worth of material and stringing it out into 1.5 hours. It appeared to have been designed so anyone channel-surfing could get an orientation as to what the program was all about regardless of when they tuned in. That's kind of lame if you're watching the whole thing from start to finish, methinks.

Labels: birdies, cenozoic, mammals, movies, tv

The New York Times reviewed a new book about birdwatching this weekend. If you can agree with the statement, "I can't think of any activity that more fully captures what it means to be human in the modern world than watching birds," then you might enjoy Jonathan Rosen's The Life of the Skies. The review (by Robert Sullivan, who wrote the book Rats, which has the best cover of any book ever) is astonishingly well-connected (in the Internet sense of the word): it weaves in allusions to Robert Frost, Jack Kerouac, and Theodore Roosevelt. I haven't read The Life of Skies yet, but it is now on my list.

I love running into birds. The other morning, when it was relatively warm, Casey and I went for a walk in the Zoo, and saw a pair of red-shouldered hawks (wild, not caged) building a nest in one of the big old orthern red oak trees there. It was cool to see: they were collecting sticks several feet long and doing short fly-hops through the canopy as they maneuvered into their nest site. Today, we went back and looked for them again, but there weren't there. Maybe out hunting?

In DC, the winter weather persists. It was cold and windy this weekend, and daylight savings time didn't help much. Soon, (very soon, I hope), the weather will warm and the birds will return. Right now, there's nothing to look at except rocks, cold rocks. Some of my Honors students and I got out in the field today to do measurements for their various projects, and when the sun was out, it was pretty nice. Still fleece and jeans weather, but you can sense spring is on the way.

Labels: birdies, books, nova, teaching

I have a confession to make. Geology was not my first love: birds were. I spent one summer in college watching cattle egrets. That research project helped me get into ornithology, & I've kept "birding" as a hobby ever since. Even these days, I don't usually manage to get through a geology field trip without pointing and shouting "Look! There goes a pileated woodpecker!" (or a Cooper's hawk, etc.) Birds are everywhere, and they're great.
Accordingly, I was pleased to get these photos Friday from my colleague, NOVA biologist Bill Gorham.

This is a female cardinal (Richmondenis cardinalis). She has a unique look: her head is white! Bill calls her Ms. Whitey.

He tells me that the bird "has been a visitor in my yard for over a year. Last winter she just had a white 'collar' around her neck, then during the summer her whole head gradually whitened."
Bill continues: "I understand the term 'leucistic' applies because it is certainly not albinism but a loss of all pigments in certain areas... I would have to guess that the progressiveness has something to do with maturity. She mated and had chicks this past summer but I think she was a youngster last winter. She is also a member of a local tribe of cardinals that get bald every summer in July and August. First it was just one male (who we called 'Baldy') but now there are several males and several females. I don't think it is mites; I think it is some kind of heat response. When they molt in the fall they get a full head of feathers again."

A few points to be made here: (1) I like sharing images of natural oddities, which is why I'm posting these images [with Bill's permission] here; (2) I like having colleagues who share images of natural oddities [I like the fact I'm part of a community of people at NOVA who are curious about the natural world] and (3) I want to know what the heck is going on with this bird: I think it's weird that it's progressive whitening like Bill describes. I mean, I can see a certain region of the cardinal embryo mutating a gene (which subsequently gets copied & copied) leading to albinism in certain portions of the body (which then remain constant over the bird's life), but I find it truly odd that the area lacking pigment has increased over time. That's remarkable! If anyone has any insights into this "rare bird," let's hear it...

Labels: birdies, evolution, nova