Devils Postpile National Monument EarthCache
Devils Postpile National Monument
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Located in Devils Postpile National Monument.
Approximately 100,000 years ago, a lava flow erupted two miles upstream from the location of today's Monument. As it flowed down the Valley, it eventually ran into an obstruction which served as a dam to the lava's path. Pooling up to as deep as 400 feet behind the natural dam, the lava cooled. Conditions were such that the lava--that was incredibly uniform in its mineral composition--cooled at a very slow rate. As it cooled, it contracted and cracked, forming hexagonal columns. 80,000 years later, a glacier flowed through the same valley, overriding the formation and eventually revealing the sides and tops of the columns. Glacial polish can still be seen today at the top of the formation.
Information from Devils Postpile National Monument Website. WWW.nps.gov
Here are the logging requirements. E-mail me the answers to the following questions. Please do not post the answers in your log, even if the answers are encrypted.
Go to N 37 37.541 W 119 05.102 --Who took the photo and what park did Devils Postpile National Monument used to be part of?
N 37 37.519 W 119 05.109-- What formed these columns? How many inches were the cracks?
Follow the trail to the top of the monument, look at the top view of the columns and estimate the angle made (in degrees) by the cracks.
Finally, post a photo of you or your gps with something in the Monument you found interesting.
Additional Hints
(No hints available.)