The coordinates are on the trail to Mount Whitney. It is at high elevation and requires a wilderness permit to enter, even for day hikes. Be sure to be prepared if you attempt this EarthCache. There is no need to leave the trail for the EarthCache.
Where ice glaciers are made up of mostly ice flowing down hill. Rock glaciers are a mass of rock debris that are mobilized by ice. They are made up of mostly rock with enough ice to let the rock slip past each other. In order to form, there must be a large supply of rock debris, a cold climate, and a steep enough slope.
The rock glacier example is located just north of the coordinates, according to the geologic map of the area. It looks like a hillside covered in a bunch of rocks, but apparently, there is ice beneath the surface that allows the rocks to slowly move downhill.
Geologists are split on how rock glaciers form. Some believe they are dieing ice glaciers that no longer receive enough snowfall to remain an ice glacier. While others think they form independently from an ice glacier. In this independent process, talus forms on a steep slope and melting snow percolates into the rock crevices where it refreezes. It is possible that both process have formed individual rock glaciers.
Logging questions:
- The text "GC3R4WJ Mount Whitney Rock Glacier" on the first line.
- The number of people in your group (put in the log as well).
- What would the field geologist have to have done to identify the area as a rock glacier?
- Where would the source of the water for this rock glacier currently come from?
The following sources were used to generate this cache.
- Moore, James G. 1987, Mount Whitney Quadrangle,Inyo and Tulare Counties, California Analytic Data. U.S. GEOLOGICAL SURVEY BULLETIN 1760.
- Moore, James G. 2000. Exploring the Highest Sierra. Stanford University Press.
- Moore, J.G., 1981, Geologic map of the Mount Whitney quadrangle, Inyo and Tulare Counties, California: U.S. Geological Survey, Geologic Quadrangle Map GQ-1545, scale 1:62500.
- Dr. Bruce Railsback; Rock Glacier Image http://www.gly.uga.edu/railsback/GeologicalDiagrams2.html
- Rock Glacier Working Group http://www.uibk.ac.at/projects/rockglacier/rockglacier_intro.html