Monday, June 27, 2011

Cinder Cone Hike

The hazard of living in new places is that, as soon as you step out your door, you see something fascinating. Here, I live atop a volcano that last erupted about 2,000 years ago, so all manner of exciting lava features are present. We have lots of time to explore the lava: we live 18 miles from the nearest civilization, and have no cell service or wifi, so our spare time consists mainly of reading, watching movies, and hiking. (Rough life, eh?)
A couple weeks ago, some of the rangers and I decided to go for a short hike up one of the cinder cones. While we were only out for a couple hours, we saw a huge variety of interesting things.
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Wild alium (or onion) grows frequently on the sides of the cinder cones, and was just beginning to bloom. Native Americans used to use the bulbs in soup.
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Many of the cinders here exhibit an iridescent, glassy sheen oddly reminiscent of an oil slick. (This iridescence shows up quite poorly in photographs, but is gorgeous in person.) I haven’t yet heard a satisfying explanation of how this happens, but I’m exploring it.
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This is a ribbon bomb – the result of a small piece of lava stretching out and cooling as it flew through the air. This one seems to have twisted a little as it flew, resulting in this curled shape. This was the first time I’ve found bombs in the wild, so I stopped to examine every single one.
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This is an iridescent ribbon bomb, which was quite exciting to find. Best of both worlds!
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This is a type of volcanic bomb called a cow-pie bomb. They’re the result of a glob of erupted lava that began cooling, but was still partially liquid when it hit the ground, resulting in a squished appearance that exactly mimics that of a cow-pie.
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When I first saw these cow-pie bombs, I thought “Oh, best not put my foot in that,” and advised my companions of the hazard.
Whereupon, one of the more experienced rangers reminded me that there are no cows in the National Monument.
We’re not in rangeland anymore, Toto.
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This is some bitterroot just beginning to grow. Bitterroot has gorgeous white or pink flowers, which are usually between 1 and 2.5 inches across – a little larger than the plant is tall. The roots were used as a food by the Native Americans: the bitter taste disappears when boiled. These are some of my favorite flowers, so I’m quite looking forward to when they bloom.
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We found a few chunks of tachylite, a type of volcanic glass that forms when lava cools very quickly, without having time to crystalize at all. This is like obsidian, but basaltic instead of rhyolitic. They’ve found a couple arrowheads made of tachylite here, but most of the arrowheads found here are obsidian from nearby Big Southern Butte, or from an obsidian bed in Utah.
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One of the best parts of climbing up the cinder cones is the great view that one gets of the other nearby cones. This one is Inferno Cone, which actually has a short, steep trail up one side for visitors to climb up. Learning the names to so many cinder cones was a little tough at first, but this one is really easy to recognize this one because it’s entirely black, with a lone tree on top.
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This is a dwarf monkeyflower, and it’s the another pink flower that favors cinders. These flowers are quite small – between a half inch to an inch. These flowers are growing mainly on the loess that has settled down amidst the cinders, rather than any homegrown soil – not enough time has passed for much of this lava to break down into soil.
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Any home-grown soil that is found here owes much of its existence to lichen. We found many delightful varieties of lichen on this hike, in just about every color, including this fuzzy gray one. This lichen actually turns green if you pour water on it – definitely a fun trick. Lichens are a symbiotic relationship between a fungi and a lichen, and they are some of the first organisms to live in lava fields, breaking down the rock and forming soil for first mosses, then plants and animals, to live in.
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(I also discovered my camera’s filters that day.)
This is a dead Limber Pine tree. These trees are very bendy, in order to cope with the wind, and frequently only have branches on one side. This one may have been killed by Dwarf Mistletoe, a native parasite that attacks the limber pine.
Living where you work can be kind of strange and stressful, but the location entirely makes up for it. When I have time, I really relish getting out of the house, off the beaten path, and into the sunshine – especially since the rocks and plants are fantastic.

Tuesday, June 14, 2011

Washington to Idaho Road Trip, Featuring Basalt

About two weeks ago, in May, my mother and I set off from her house in Seattle to travel to Idaho. I live (and now work!) in Idaho, but was back home to visit my brother and sister-in-law, who were in town for a spell (and newly expecting a baby!) This trip was held together tenuously from the beginning, and quickly began to disintegrate along the way. Luckily, we got to see some awesome stuff along the way.

MSH2Our first stop was Mt. St. Helens, always a favorite stop. I’ve never been here so early in the season, so I’ve never seen it so snowy! This iconic view from the Johnston Ridge Observatory really lets you look into the crater and see the lava domes (here, due to the snow, they look like a vague bump towards the back of the crater.) This spot also gives you a good look at the Pumice Plain, (the low area in the foreground) that consists of debris avalanche hummocks mostly covered in pyroclastic flows and ash fall deposits.

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This is a nice outcrop near the Johnston Ridge Observatory, that really clearly demonstrates the layered nature of stratovolcanoes. You can see different lava flows (andesitic and basaltic) alternating with layers of ash and possibly pyroclastic flows (in this instance, I’m not sure which it is, or whether it is a combination of both.) All the different colors are a result of hydrothermal alteration on groundwater that seeps into the deposits, is heated by the still warm deposits, and encounters pockets of gas.

Once we left Portland, the cold my mother had been fighting off finally caught up to her. We stopped in a town called Cascade Locks for the night, slept in late the next morning, and then got some restorative chowder before heading out.

ColumbiaRiverRowenaBendsWe took a short side trip off I-84 on an Oregon 30 between Mosier, OR and The Dalles, OR. When I was first moving to Idaho, we discovered this scenic jaunt, and it was great to see it again. Partway through, there’s an overlook of the Columbia River and the Columbia River Flood Basalts at a place called Rowena Crest.P5250378

The road down from the overlook is this delightful road called the Rowena Loops. It’s quite exciting (especially for one’s passengers!)

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Somewhere along the highway near Pendleton, we pulled off the highway to look at this cool cement plant. After this, though, we encountered some pretty intense rain, and ended up staying in La Grande for a night.

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Once we got to Boise and picked up my car, we joyfully discovered that it had some sort of gas leak. (This heap – I mean, jeep is beginning to get on my nerves.) We dropped it off at the shop, and drove into the foothills above Boise to camp. Along the way, we stopped at Diversion Dam. It was built in 1909 to supply water to another, older system of canals, to irrigate nearby farmland.

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One of the cooler things about it was the logway – a special portion of the dam constructed to allow logs from logging upstream to pass through the dam. (The area upstream is the Boise National Forest)

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It was interesting to see how the water from the less constricted logway (on the left) interacted with the water that was forced through the dam. Despite having an initially smaller outlet, the greater force enabled it to travel farther & spread out more before the turbulence achieved equilibrium. (I’m sure there’s a better way to phrase that, but my engineering-oriented physics class didn’t cover fluid dynamics… which is what I personally wanted to study! Someday maybe I’ll get to.)

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We passed by several reservoirs, including this one. The differential erosion happening in the basalt here was really fascinating – the lower flow must be much harder, to have resisted so much more than the upper flow.

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The road passed through areas of this potassium feldspar rich granite. The best exposures were alongside one of the dams, where the road was quite literally one lane carved into the cliffside, frequented by large trucks hauling boats. Needless to say, we didn’t really stop for picture taking.

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When we finally began pitching our tent, we realized that the rainfly was still in Washington – and rain was predicted. My mum had this great idea to make one out of free garbage sacks and little bits of tape – which luckily worked pretty well, though it didn’t rain.

After that, we picked up my car (which luckily only had a leak in the fuel lines!) and checked the weather forecast. Since it was predicted to rain more and my mum was still under the weather, we decided to part company that day, instead of camping through the weekend. She headed west to Washington, and I headed east to my summer job. Much as a few days of mother-daughter camping would have been fun, it was nice to just call it quits and end the stress.

Sunday, June 5, 2011

Weird AND Scenic: Accretionary Wedge #34

“… a weird and scenic landscape peculiar to itself” was how President Calvin Coolidge described Craters of the Moon when he proclaimed it a National Monument in May of 1924. For my entry in the Accretionary Wedge #34, hosted by the lovely Dana Hunter over at En Tequila Es Verdad, I'd like to talk a little bit about some of the weird things we have here!

In 2000, the original boundaries of the Monument were expanded to overlap with an area of BLM land, and the area is now managed cooperatively by the NPS and the BLM, and is now a National Monument and Preserve instead. I’m working this summer for the BLM, but am stationed at the NPS Monument, to increase knowledge of this cooperative management. *

The name and managing organization may have changed, but the landscape remains, well, weird. And scenic.

Blue Dragon Flow

Craters of the Moon is comprised of about 60 lava flows covering 54,000 acres, and spanning 13,000 year of time. This is the most recent area of volcanism on the Eastern Snake River Plain; altogether, the sheer mass of lava erupted throughout the ESRP has depressed the crust, resulting in a (mostly) flat valley 100 km wide. The eruptions at Craters of the Moon are the result of a 52 mile long tear where two plates of the Earth’s crust pulled away from each other, much like in Iceland or sub-Saharan Africa. The volcanoes in this picture are cinder cones that formed alongside the Great Rift.

Blue Dragon Flow

This picture shows a close-up of the same lava pictured above. This is the Blue Dragon flow, named because it’s spiny texture and blue glass coating reminded early explorers of the skin of a blue dragon. The spiny texture is the result of bubbles in the lava being stretched and popped as the flow moved; the origin of the blue glass is still unknown, although it is suspected to either be the result of higher than normal titanium concentrations or a process similar to “glazing” a pot.

Big Southern Butte

This picture illustrates another reason why Craters of the Moon is weird: bimodal volcanism. In the foreground, we have the fluid basaltic lava flows of Craters of the Moon, and, in the background, the 800 meter tall rhyolitic dome of Big Southern Butte (which lies outside the monument.) This butte was formed when very viscous lava flows piled upon one another. (It is also thought to extend about 1000 meters below the surface of the earth, but has isostatically sunk due to it’s weight.)

The compositions of these two lava types are about as disparate as lava types can get: basalt has low concentrations of silica, and rhyolite has high concentrations of silica. It is suspected that, in this location, the two lavas come from roughly the same origin, but proceeded through different paths through the Earth, which resulted in differing compositions. They both are a result of the Yellowstone Hot Spot heating the asthenosphere as the North American plate passed above it. The rhyolitic lava travelled up through the continental crust above, melting it and absorbing the silica. Later, when crustal extension of the basin and range province stretched the area out, the silica-poor crust melted (mainly by decompression), and cracked open, creating the rift zone at Craters of the Moon. Gravity readings under Craters of the Moon suggest that there may be a thick sill of gabbro, that was once part of a reservoir for feeding the basalt flows above the surface.
Rafted Crater Wall Blocks

Another really weird part of Craters of the Moon are the blocks of lava shown in the center of this picture. One of the more recent flows of the North Crater broke apart the crater wall, and rafted chunks of the wall along the top of the flow. These crater wall pieces dot the landscape in an eerie monolithic fashion, like something out of 2001: A Space Odyssey.
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And here’s the North Crater itself, with one of the rafted blocks in the foreground. The area where the flow broke out is on the back and right side of the cone seen here. The asymmetrical shape of this cone is due to the cinders accumulating on the downwind side of the vent.

Early emigrants passing through this area by wagon train described this area as “black vomit.” These early emigrants, after travelling across a harsh and demanding area, almost entirely void of water or shelter, were too weary to contemplate appreciate the landscape. Those of us privileged enough to visit in this modern day find it easier to look past the difficult environment to the gorgeous volcanic scenery and awesomely weird geology.

* Normally, I wouldn't say who I work for, however my lawyer-mother recommended I do. Plus, it's pretty stinking obvious. Please don't think anything I say is the official opinion of the BLM or the NPS, and remember that I'm still learning about this area and geology generally. Also, please don't stalk me. If you're in the area, however, please feel free to say hi!