West Antarctic Ice Sheet Stability:
Glacial Record from the Ohio Range of
the Horlick Mountains in the Bottleneck
Hal Borns*, Aaron Putnam, UMaine
Robert Ackert, Sujoy Mukhopadhyay, Harvard.
December 15, 2004 to February 15, 2005
January 2nd 2005
January 23, 2005

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View up the lateral ice-cored moraine from the base of ‘West Glacier.’

The southernmost rocks in the Ohio Range.





The Lateral Moraines of ‘West Glacier’ on Mercer Ridge

It has certainly been a long day, but not on account of adverse conditions, but rather on account of another gorgeous day in the Ohio Range! The Twin Otter did not come to pull-camp today (as expected), which turned out to be quite fortunate. The bluebird day took us back to Mercer Ridge where we checked out the last point of scientific interest pertinent to our investigation – the lateral moraines on the unnamed glacier on the western side of Mercer Ridge (henceforth, until a better name is given to it, ‘West Glacier’).

We thought we’d spend an hour or so sampling the moraine, and then start the hunt for cool rocks for the collections – but we ended up sampling all day! It turned out to be much more interesting than it appeared from afar, with a whole series of stranded ice-cored moraines showing a younger with proximity trend with the dolerites… just like the glacier higher up on the other side of the ridge! There again were distinct ridges, which I take to represent previous stable ice margins. I believe the sequence of moraines suggest that with the shrinkage of the ice mass, the flow has been diverted by subtle underlying topography that is exposed to the south of the glacier tongue. It appears, by the way the moraines splay off from one another downslope, that the glacier was diverted to the north. I am very curious to see what the ages reveal, and how they correspond to the sequence on the higher glacier.

After sampling, we spent a short period in the early evening rock collecting in one of the ‘gnome gardens.’ We went back to the sandstone terraces, with their wonderland of perched, pitted dolerites. I chose three substantial specimens to bring back, one for the University of Maine, one for the University of Maine at Presque Isle, and one for the Bates College Geology Department. I also picked a really cool cavernously weathered piece of sandstone to take back for myself.

Our final stop of the day, and likely of the season, was by my request. On our way back to camp, we stopped at the southernmost rocks (which were extended from the lower West Glacier moraines) in the Ohio Range. I found the southernmost rock that was possible to collect (a nice piece of sandstone), took a GPS location and elevation, and a photograph. This rock, with a nearby little dolerite, will be for Hal.

On our way back, the weather finally began to deteriorate, and after our (supposedly) final steak supper, we toasted yet again to our last night in the field. The visibility then became null. So perhaps there will be yet another toast to a great season in the Endurance Tent tomorrow night, though another day here doesn’t vex me in the least.

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