Site No. 12— Sherwin Grade
Highlights
- Deer Migration
- Moraines and Glaciers
- The values of wilderness
Glaciers & Wilderness
Descending Sherwin Summit is difficult with out using your brakes because you are now entering the deepest valley known as Owens Valley. This valley is a graben valley meaning that it has dropped a few feet to a tens of feet at a time as the Eastern Sierras and White-Inyo Mountains rose.
As you drive down Sherwin grade look for grayish steep marks on the Sierra mountain sides. These grayish marks are called truncated spurs by the Geologists and they indicate fault movement. Furthermore, you may notice mound of rock and soil creating a huge berm around the mouths of Pine Creek, Convict Lake, and the canyon west of Crowley Lake. These are glacial moraines (approximately 710,000 years old), which are material deposited in front of the moving glacier as it proceeded out of the canyons.
Glaciers have the ability to push vast amounts of material in front of them and when the glaciers melted these lateral moraines were left behind. Glaciers also have the ability to carve U-shaped valleys, cirque lakes, and sharp peaks called horns and aretes.
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