9: Mist, Monkey Business, and Moving Mountains

With a combination of bad weather at Mt. Kirkpatrick and scheduling conflicts keeping us in camp, we were in the doldrums during the week bracketing the New Year’s holiday. We tried to make the most of this down time, with everyone working on various personal projects, but the frustration mounted through the week as our flights were being canceled due to the weather. From the Thursday before New Year’s Eve to the Friday following it, the mountain held our goals hostage with clouds obscuring our landing site.

Meanwhile, Chris, Roger, and Adam were in a remote camp at Graphite Peak, discovering and excavating Lower and Middle Triassic vertebrates. While we languished in camp, staring at the clouds obscuring our mountain on the horizon, they discovered and excavated a considerable haul of skulls and skeletons from the Fremouw Formation exposures on Graphite Peak. To see their discoveries, take a look at their “Excavating Triassic Fossils in Antarctica” Video Report.

The New Year’s holiday took our minds off our limbo to some degree. Our party was accosted by the Beardmore Gorilla (see top photo), whose greatest threat to mankind was probably his garish shirt. In defense of my team, I felt compelled to subdue the gorilla with a football tackle in the snow.

Just prior to the stroke of midnight, we played a game of volleyball. Given how frozen the ball was, the slippery playing surface, and the ongoing celebration, the game was not a particularly elegant exhibition of athleticism, but it was good fun for the participants, nonetheless. The year 2011 was welcomed with drinks, dancing, and mutual well-wishes.

Because of the altitude, our team is always brought to and from the mountain on two flights each way. The Thursday after New Year’s Day was the first opportunity we got to fly to the dinosaur quarry, and Nate and I were on the first flight. As we approached, it was clear that a small but thick cloud was sitting right on our landing zone, forcing us to turn back. Since other nearby peaks were clear, the helicopter pilots agreed to drop us off on Golden Cap, a lower summit that exposes the same rock layers that yield dinosaurs on Mt. Kirkpatrick.

Nate and I spent most of the day exploring the extensive exposures of the Falla Formation and Hanson Formation, from bottom to top. Fresh snow from the weather that had grounded us in the previous days made prospecting difficult, but we didn't come away empty-handed. We found three thin rock horizons that contained organic material, including a coal seam from the Falla Formation, which we sampled for palynological analysis.

Our team member, Dr. Eva Koppelhus, will dissolve the rock component of these samples and then examine the organic residue for ancient plant spores and pollen, together called palynomorphs in ‘geologese.’ To learn more about this process, check out Eva's "Sampling Ancient Plant Spores & Pollen" Video Report.

Just like the fossils of vertebrate animal bodies, palynomorphs (fossil spores and pollen) often exhibit specific anatomies that are restricted to a particular geological time interval. Being far more common and widespread than, for example, a species of dinosaur, palynomorphs can serve as a very good indicator of the geological age of the sediments that contained them.

Because they're far more resistant than many other parts of plants, palynomorphs also provide important clues for understanding the ancient flora and environment that they derive from. The samples Nate and I collected come from three different horizons in the Falla Formation, and we hope they'll help bracket the age of the entire rock unit in general and our dinosaur quarry in particular.

On Friday, the bad spell finally broke and we were able to take a team of five to continue our work on the quarry. In our previous visits, we had determined that a long section of the vertebral column of Cryolophosaurus—from the middle of the back through the base of the tail—is preserved in articulation in the quarry. Our excavation strategy has been to dig a trench behind the vertebrae in order to define and isolate an island of rock about 8’ long, 5’ wide, and 2’ deep, with all the bones in it (see Photo #1 below.) This island can then be split into smaller bone-containing blocks.

While sound, the plan is slow in execution because the rock is very hard—in fact, it's the hardest I have ever worked with in 15 years of conducting paleontological fieldwork. Because the climate here is so cold and dry, there's virtually no weathering to weaken the chemical bonds cementing the sediment together into rock. We're entirely reliant on power tools to remove the rock, using a combination of electric- and gas-powered jackhammers and rock saws to remove the matrix (see Photo #2 below.)

Working in temperatures of -30° C, we finished carving out the deep back trench over the course of Friday and Saturday. Due to the cold and oxygen-starved atmosphere at such a high altitude, our power tools do not behave optimally—especially those that use a gas-and-oil, two-stroke fuel mixture. We finally coaxed them to life after letting them warm up in the exhaust from our two generators, which power the electric jackhammers.

Mustering our collective creativity to troubleshoot such problems is typical of any fieldwork, but down here, the nature of the problems (cold, altitude) is fundamentally different from almost any other locality in which any of us work. Changing spark plugs on a jackhammer or adjusting the carburetor setting on a rock saw is not a big deal in most field sites, but on Mt. Kirkpatrick, taking your gloves off for more than a few minutes gets painful.

While daily air temperatures don’t seem to vary much, we feel the effects of wind chill and cloud cover very acutely on the mountain. Some days are cloudless, calm, and therefore comparatively warm. Other days are cloudy, but because of our altitude, the clouds are often below us.

The weather does change throughout the day, however, and last Friday, clouds crept up from the valley over our landing zone. We had to call for an early retrieval from the mountain, and the helicopter flew in under low visibility. Because the engines generate a fair amount of condensation under such conditions and the rotors blow it down around the helicopter, our skilled pilot, Dustin, was forced to take off relying entirely on his instruments, as the visibility was nil (see Photo #3 below.) We owe much to the highly skilled aircrews that work here.

Monday was a big day for us. We were able to get the first large block of rock off the mountain, a 300-lb. chunk containing parts of three vertebrae from the middle of the back, along with some associated ribs. To split and extract the rock, we drilled numerous holes in lines to define where we wanted the rock to crack, sort of like a perforated seam on a checkbook (see Photo #4 below.) Wedges and feathers were then inserted into the larger holes, which were drilled using the jackhammer. Using crack hammers and sledge hammers, we then pounded the wedges into the rock to induce and propagate cracks. (To learn more about the equipment we use, check out our Tools Photo Gallery.)

The rock here often misbehaves and doesn’t crack along the line of holes we drill, and in this case, the rock didn’t break as deeply as we would have liked. The ‘up’ side to this is that we had a smaller block to haul over to the landing zone. Although only a short distance, the four of us hauling the 300-lb block over uneven terrain at high altitude needed several legs to complete the move. We felt triumphant but exhausted when we returned with this prize.

More soon,
Pete