22 January, 1999
Greetings from McMurdo:
Last night we had another wonderful flight. Greg Liebert was our pilot. We flew in 31Lima (the name of that parcticular AStar) southwest to Heald Island. We got great views of Mt. Discovery. This is another of the landmark volcanos here. The dates on the volcanics here range in age from about 14 million to just a few hundred thousand years old. Remember that this part of Antarctica is a rift zone - similar to the Great Rift in Africa. As a matter of fact, one of the signature rocks of Mt. Erebus is keynite - found only in one other place in the world- Kenya.
We circled over Heald Island, while Dr. Denton concentrated on photographing two huge dikes. The upper dike has been dated at 14 million years old, while the lower one is dated at 4 million, We then landed near the lower dike and cone. The colors on Heald were really appealing after the relentless brown of Beacon. The island had been scoured down to bedrock by glaciers and the rocks were yellow, orange and white. Many of the basalts had beautiful olivine crystals in them. I collected some samples and will share them when I return.
We then flew to the top of Heald, and Drs. Sugden, Denton and I walked down to another dike. We observed more beautiful polygons in a certain area. They were strikinly different thatn in Beacon in colr- here the rocks were all white sandstones.
We continued down and had a moment of sitting. We lay on the rocks and just looked out at the Royal Society Range. We had Discovery to our backs and the two- humped Dromedary to our faces. I had a hard time believing that I was sitting here with two such distinguished geologists.
The helo came down to pick us up and we then flew up the Radian Glacier. It was quite a climb, and when I looked back at Heald - it looked miniscule. My ears began to pop.
We flew up Radian because the valley walls are dotted with volcanics. These have all been dated and Dr. Denton just wanted to photograph a few. Professor Sugden was interested in some slope measurements, so we landed on one volcanic cone that had been dated at 2 million. We hiked down and Dr. Sugden took measurements at different locations. At one point we went down to the glacier's edge and took an altimeter reading and then took a reading at the next moraine line. This can show how much the glacier has grown over time. The view was just spectacular - Discovery in the distance, the terminus of the Radian Glacier, the Walcott Galacier and little Heald Island.
We hiked all the way down to the base of the cone - it took us about 45 minutes. We were ready to be picked up, but when we tried to use the radio, we realized that the battery was dead!!
Greg, our pilot, had been in Search and Rescue in the Coast Guard. He had just been telling us how much he missed it!! Well here was a chance at a minor reenactment!!
We reclined on the volcanic scree and talked while we waited for him to fly down. We had told him to give us about an hour; right on time we heard the helo start up and he hopped down and picked us up.
We all had a laugh about the radio, but I absolutely decided to be responsible for recharging the batteries!!
We went to refuel at a fuel cache at The Pyramid. When we flew out of the mountains and over the Koettlitz Glacier, we got really blasted with wind. It was the first time I had caught my breath in the helos - it was like the little squirrel just could barely make it in the wind. Although it is difficult to do a job like fueling in the wind and cold, Sugden and Denton leapt out of the helo and got everything started for Greg. This made it go quickly and we were on our way in about 20 minutes. I helped Dr. Sugden carry an empty barrel back to the cache - the wind had blown it away.
We continued to fly over the valleys, and got a look at the lake that Chris Hende used to develop the idea of lake conveyor deposits. This idea explains some of the strange "moraines" that are seen here. It posits that material on top of these lakes eventually falls through the ice by melting through. It clarifies how one can see boulders on top of little pyramids of smaller grain size.
We flew home about 4 am and to bed!!
Goodnight (morning!!) from McMurdo!!
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