mpollock June 6th, 2012
FILLMORE, UTAH – Whitney and Matt took charge today, leading us on an investigation of the lava flows that extend westward from the Miter cinder cone.
We picked our way across the sharp, rubbly flow surface and learned the importance of careful observation. Although we weren’t looking for bombs and xenoliths, we found both along our path.
Whitney had a successful day of mapping the margins and morphology of a couple of complicated lava flows.
Matt’s productive day included finding a spectacular fault exposure, where he made lots of measurements on the fault and associated joints.
Overall, it was a strong start to the field project, despite the searing sun and blinding wind storm.
We were rewarded for all of our hard work.
We hope every day of our field season is just like this one (minus the wind).
mpollock April 3rd, 2012
Wooster, OH – Today’s hazards class was devoted to lava viscosity. Viscosity plays an important role in controlling how volcanoes behave, from determining how quickly magma ascends to whether the eruption will be explosive or effusive. In Hazards, we’ve been discussing the factors that control lava viscosity, like silica content, volatiles, and temperature. Although we’d love to experiment on real lava, like the folks up at Syracuse University, we just don’t have the right set up. Instead, I borrowed Ben Edwards’ (Dickinson College) idea of using corn syrup. (I’m not the only one).
We simulated lavas of different viscosities by varying the temperature of the corn syrup and adding rice and sand. Then, we poured our “lava” down ramps and timed how fast they moved. We used their velocities to calculate viscosity and compared our results to real lava.
We also blew bubbles into our “lavas” to simulate volatiles.
mpollock June 26th, 2010
Campers from the Buckeye Women in Science, Engineering, and Research (B-WISER) science camp visited the Geology Department last Thursday to study the role of lava viscosity in volcanic eruptions. We used corn syrup as our ‘lava’ and experimented with ways to increase and decrease the viscosity.
To top it all off, I received a special thank you – a serenade by the girls. Here it is: the twinkle remix.
Mark Wilson April 16th, 2010
SYRACUSE, NEW YORK–Today I gave a presentation at Syracuse University as part of the fifth annual Central New York Earth Sciences Student Symposium. My topic was the rise of modern marine ecosystems in the Jurassic. Exciting enough, of course, but the real fun was in an event which caught me by surprise: a “lava pour” organized by Professor Jeff Karson with the Sculpture Department at Syracuse. (This is a type of interdisciplinarity I hadn’t seen before!)
The pour, as they call it, began with the addition of about 100 pounds of basalt (collected in Oregon where they have plenty of it) into a hardened steel cauldron. The cauldron is then lowered into a below-ground furnace and heated for about four hours until all is incandescent. Several people in protective gear (it would not protective enough for me, though!) open the furnace and attach a winch to the cauldron and lift it to the surface. At this point the crowd (including me) had been pushing as close as allowed to the furnace. We immediately backed up when the blast of heat from the cauldron — which was glowing like the sun — struck us. Molten rock is serious stuff.
A bit of the lava was first poured into a porcelain pipe bent like an elbow with the lower part ending in a large basin of water. The pipe had been plugged at the base with wax so the lava would build up before flowing through to the water. The idea was to make a lava pillow, a type of flow structure made when a natural flow meets water as under a glacier, in a lake or in the ocean. (See the natural pillow lavas studied last summer by the Wooster Iceland Team.) The wax immediately and explosively ignited, sending a spout of flame upwards which took everyone by surprise (including the crew). The fire was short-lived, though, as the lava flowed through into the now-boiling water.
The second pour was onto a cold rock monitored by a digital remote thermometer to record its cooling rate. This time the lava poured out like syrup, making a flat, bubbling sheet which quickly grew a dark crust which spattered tiny glass shards as the cooling bubbles burst.
The third and final pour was onto blocks of dry ice, apparently to simulate the surface of Mars. (Really. Not just to “see what happens”. This is professional geology, after all!) The lava hit the dry ice with an extraordinary hiss and then skittered off onto the sand below. Apparently the vapor built up immediately by the rapidly-sublimating ice did not allow the lava to stick or even stay on the ice itself. The result was ropy strings, droplets and “angel hair” of cooled lava.
Afterwards, when the cauldron had been scrapped empty and the heat had dropped to a tolerable level, we gathered around the three pour sites and marveled. The flow on the rock slab continued to bubble and crack, producing some exquisite brown fragments of almost-transparent glass. We picked up a few cooled pieces and tried to imagine this process scaled up to natural proportions.
Thank you to Jeff Karson for such an innovative idea, this lava pour, and sharing it with all of us. Way cool. Mike Cheatham has posted a webpage of photos showing our lava pour in its stages.
Mark Wilson March 11th, 2010
ZZYZX, CALIFORNIA–This was our last full day in the Mojave Desert, at least for this trip. Technically it was our coldest start yet (40°F), but the bright sun and lack of wind made it seem like our warmest. The day was mostly unstructured because we were going to try to find a geological site none of us had seen here: the lava tubes in the cinder cones area of the Mojave National Preserve. It was a good thing we left our schedule open because we missed not one turn, not two turns, but three crucial turns before we finally entered the tubes. I’ll take full responsibility, although in my defense I must point out that the Preserve is very coy with their signage and directions!
After another delicious lunch packed for us by the Desert Studies Center staff (a shout-out to the world-class cook, our friend Eric), we drove north to Resting Springs Pass to study a famous exposure of a welded tuff. Our last stop was a descent through the 500,000 year-old beds of ancient Lake Tecopa to China Date Ranch where we looked around the oasis and had the famous (and expensive .. and over-rated) “date shakes”. (Think flurry with little date bits thrown in.) The students and other faculty enjoyed them, though, and they were in their eccentric way a fitting end to our Mojave adventure.
Unless my colleagues surprise me this evening, this will be our last post from the Mojave. We will have many more entries for this field trip, though, as we sort through student images and observations back on campus. We will also add more technical notes about the sites we saw, and maybe even throw in a video or two. It has been an extraordinary trip which will live in our departmental memory for a very long time.
Mark Wilson March 10th, 2010
ZZYZX, CALIFORNIA–One of the most attractive aspects of geology is how many materials and processes are included in the study of the Earth. Today’s field experiences show this diversity. One of the best reasons to teach in a liberal arts geology program is that we are continually in touch with topics outside of our original disciplinary training. This trip has been so much fun in part because all four of our faculty are involved at each of our stops, and we always learn from each other by having no fear about asking any questions. We seem to be successfully modeling this attitude with our students because they certainly have no hesitation in asking questions either.
Our teaching approach in the field has been to introduce students to the general framework of information about a particular site, and then let them explore the area, each bringing back questions, observations and specimens for a summary session with all the faculty. This has worked very well with this class because they are advanced and very enthusiastic students. Their curiosity has been an inspiration.
This morning was sunny, windy and cold (starting in the forties and not getting past 53°F). It hardly mattered though because we had so many interesting outcrops to study. Our first stop was Hole-In-The-Wall in the southeastern quadrant of Mojave National Preserve. Here are magnificent tuffs from an explosive volcano eruption about 18.5 million years ago. Dr. Pollock will have more to say about the geological details.
Our second stop was to climb the Kelso Dunes in the southwestern portion of the Preserve. The pile of sand here reaches 160 meters. It is trapped against the Granite Mountains in an endless swirl of winds. The students climbed the highest and most popular dune in the complex while the faculty chose to ascend a slightly lower but untrampled dune. Oddly enough, when we stood on these dunes in the middle afternoon, for the first time the wind stopped!
Our last two stops were relatively brief. One was at an outcrop of the Chambless Limestone, a Cambrian unit showing oncolites and dolomite-filled burrow systems. The other was at the tip of a lava flow from the cinder cones near the center of the Preserve. We returned to the station in the early evening with sand-filled shoes and sun-reddened faces. Another wonderful day in the Mojave.
Mark Wilson March 9th, 2010
ZZYZX, CALIFORNIA–Our second and last stop of the day was Amboy Crater, which is about halfway between Barstow and Needles, California, near Route 66. Meagen Pollock, our ace petrologist, prepared us well for this visit, so we’ll wait for her to post the geological details and her expert observations. I want to prepare the ground with some photos of our hike up this remarkably recent cinder cone.
mpollock July 12th, 2009
Done! Today was our last day in the field. Rob finished hunting for zeolites on Vatnsdalsfjall.
To get to the last field area, we had to cross “the deadly fields of sadness,” hummocky and swampy fields that are treacherous to walk across. One of us (guess who?) wished for a “luck dragon to fly us to the top of the mountain.” Then we had to cross a river. Adam kindly offered piggy-back rides to everyone. Rob took him up on it. Meanwhile, Todd and Meagen took a different approach.
Yesterday, Adam finished his field work, but the day started with a small adventure. On our way to Adam’s last field site, the car somehow found a ditch! Fortunately, a nice elderly Icelandic farmer knows charades, and Meagen was able to ask him for help. He came to the rescue with his dog and his tractor! After that, we hit the rhyolite jackpot and Adam completed all of his I.S. sampling.
Like the Estonia Crew, we’re almost ready to head home, but not before we see Krafla and meet with the Hales Fund Iceland Group.
mpollock July 4th, 2009
We’re on the Skagi Peninsula now and internet access is a little more random. We started field work on Rob’s and Adam’s projects this week. Rob found some awesome zeolites – too many to name – and a lot of altered basalt (my poor babies!). Adam ran into some trouble early on because many of the rhyolites appear highly altered, but has managed to find some pretty decent samples that he can use for geochemical analyses.
We’re living in a house with 12 people – sounds like a reality show (The Geology World or Big Brother: Geo-Style). Meagen is in a room with 4 girls – it looks like their clothes exploded. Todd, Rob, and Adam are sharing a room – it smells…refreshing(?). They have swum in the arctic ocean EVERY DAY since we arrived. They are CRAZY!
We’re going to be here until July 14. Sadly, we’ll be missing the Hunavaka, a local celebration with colorful balloons and music. Still, every day is a celebration when you’re doing geology!