Friday, December 19, 2008

Edmunds Col viewed from Mt. Jefferson (top photo) and from the Gulf Side Trail north of the Col (bottom photo)

These photos of Edmunds Col show evidence of the continental Wisconsinan glacier as it came up and over the north slope of the Presidential Range and then spilled down into Jefferson Ravine and the Great Gulf. In both photos what stands out the most is the 'Roche Moutonees', the large rock formations that have been 'carved' smooth on the side towards the direction the ice came from and broken off, or rough, on the side in the direction in which the ice flowed 'departed' so to speak. Richard Goldthwait theorized that the continental ice sheet flowed over this landmark after smaller, alpine glaciers had already carved out the lower cirques on the mountains. He also observed that Edmunds Col could be what is left of arĂȘte, a serrated knife edge that you see in the alps and elsewhere that are crossed by sitting down and straddling them (e.g. the knife edge of Mt. Katahdin) and that form between glacial basins, but that would have been when the White Mountains were much younger and possibly much higher.

Goldthwait has detailed 9 definite cirques and 3 small rock basins formed by these local glaciers which he concluded had a maximum length of up to 8 miles long at times and radiated out from the peaks towards the north west, north, east and southeast. Goldthwait’s nine cirques are what are now named Oakes Gulf, Gulf of Slides, Tuckerman’s Ravine, Huntington’s Ravine (see Andrew Reily’s paper above), Great Gulf including Jefferson’s Ravine (see below), Madison Gulf, King’s Ravine, and Ravine of the Castles. To these he added three steep sided cirque-like rock basins.