Monday, July 21, 2008

Rock Glacier: Near the Top

It may seem like this ongoing saga of rock glacier climbing is taking forever - but by the time MOH and I reached this level, that's what it seemed like to me, too - forever: take one step, pause, look around, breathe. Did the view change? Should I take another picture? (You may be thinking, "no," by this time!) Take another step, pause, breathe, look around. How much higher will we go?

Well, we got as far, as high, as the picture above. More rock glacier ahead! Still can't see if the snow, ice, or whatever is stuff of glaciers or not! And maybe the rocks, overall, are larger this high on the rock glacier - but I wasn't measuring, I was dragging myself around them!

Closer, closer...

The area in the above photo, right below the outcrop that splits the ice/snow chute in two, was where Osborn and Bevis (2001) saw and photographed a bergschrund. It's not visible above - could it be covered by snow still left in early July? Or could there be one lower down, below the highest ridge of the rock glacier?

Above, a photo taken just to the right of the previous one, showing the steep, cirque headwall made of layered Prospect Mountain Quartzite, with Wheeler Peak right at the top of it all.

Below, two photos with a closer view of the distorted bedding in the quartzite. Judging from some striated to slickensided surfaces on thin, dark shaly faces of quartzite blocks in the rock glacier, I suspect some bedding-parallel slip of some sort.

1) The photo above shows the lower, light-colored, quartzite near the base of the cirque headwall with some distortion along a contact with part of an overlying section of darker quartzite.

2) Above, higher still in the cliff, the darker layers show more distorted bedding and some folding.

References: see previous posts.
And also this additional one from John Van Hoesen at Geological Musings in the Taconic Mountains:

Van Hoesen, John G., 2003. Late Quaternary Glacial and Periglacial Environments, Snake Range, Nevada. [PhD Dissertation]: University of Nevada, Las Vegas. 225p.

And check this out from his website!

Wheeler Peak is inside Great Basin National Park.

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