These coordinates are at a pullout along the main road. It is not a good place for leaving your car unattended for long periods, but you should have enough time to see the moraine.
Glaciers filled the valley during at least the Tioga (14-25 thousand years ago) and Younger Tahoe (42-50 thousand years ago) glaciations, and probably at least one pre-Tahoe glaciation. The rivers of ice flowed down the valley eroding out a typical U-shaped valley (See Kings Canyon Valley Geomorphology).
The eroded material was transported down the valley embedded in the ice. At the end of the glacier, the ice melted and the solids dropped down to the ground. If the climate remains stable for a long period of time, the end of the glacier remains at about the same place and the material dropping out of the ice builds up at the same place forming a ridge of unsorted (containing a wide range of grain sizes) sediment. These moraines that form at the end of the glacier are called end moraines.
End moraines can only be created as a glacier retreats. If the glacier grows, it will actually overrun the old end moraines destroying them. As a glacier retreats, it sometimes pauses for a time at the same spot or advances forward for a season or two, bulldozing some material in front of it. Then it resumes retreating leaving a small moraine.
Logging requirements:
Send me a note with :
- The text "GC4QPY8 Kings Canyon Glacial Moraine" on the first line
- The number of people in your group (put in the log as well).
- Based on the size of sediment in the road cut across the street, is the road cut part of the moraine?
- What is the orientation of moraine in relation to the length of the valley? Is that consistent with a glacier flowing down the valley and melting at this point?
- Extra: Can you find another moraine along the road? (36.78302283, -118.63627740) How does the location of the second moraine relate to the first and how a glacier grows and retreats.
The following sources were used to generate this cache:
- Garry Hayes, Glaciation of the Sierra Nevada; http://virtual.yosemite.cc.ca.us/ghayes/sierragla.htm
- BSG 1996-2008; last modified: 14th Sep 2009; Glacial Erosion Landforms (Large-scale); http://www.geomorphology.org.uk/pages/education/alevel/coldenvirons/Lesson%2011.htm