Rising Hot Rock EarthCache
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Difficulty:
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Terrain:
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Size: 
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A xenolith or "foreign rock" is a rock fragment which becomes enveloped in a larger rock during the latter's development and hardening. In geology, the term xenolith is almost exclusively used to describe inclusions in igneous rock during magma emplacement and eruption. Pieces of mantle rock are often brought to the earth's surface in basalt lava flows. Xenoliths may be engulfed along the margins of a magma chamber, torn loose from the walls of an erupting lava conduit or explosive diatreme or picked up along the base of a flowing lava on earth's surface. Mantle xenoliths, pieces of rock carried to the surface by volcanoes, are the only way to see the deep rocky interior of the Earth, called the mantle, directly.To be considered a true xenolith, the included rock must be identifiably different from the rock in which it is enveloped. Xenoliths provide important information about the composition of the otherwise inacessible mantle. Nearly everything we know about the rocks of the deep crust and the earth's mantle beneath it, comes from xenoliths found in lava.
To log this earth cache you will have to email the GC# code along with the answers to the questions below:
1. Are the xenolith you see in this area lighter or darker than the outter rock they are enveloped in?
2. There is a xenolith rock-cluster about twenty feet north of the posted cords, how big do you think it is?
3. How many xenolith did you notice on the way up?
RESOURCES:
1. WIKIPEDIA: XENOLITH
Additional Hints
(Decrypt)
Guvf vf n qveg ebnq gb gur pbeqf nobir, qevir fybj naq or pnershyy jngpu bhg sbe ubyrf naq qvcf.