Here is a location that
demonstrates the violent uprising of the Sierra Nevada
Mountains.
All along this section
of the 108 corridor one can see two prominent geological
formations, the first are occasional buttes (see GC2HJPM) and the
second are strange rocks jutting from the ground at weird angles.
This second formation is what this earthcache is
about.
The Sierra Nevada Mountains of
California formed about 80 million years ago when volcanic action
started to push up a new range of mountains, many of these ancient
peaks can still be seen around the area as well. At these locations
we can see some of the remnants of this action. Most of the rocks
in the area are volcanic in nature and came from one of the
volcanoes further up in the foothills exploded. It must have been a
rather violent eruption to have spewn rocks this far. So all this
means that these rocks are basically hardened lava. When rocks are
throw violently they usually have very little shine to them because
the volcanoes that erupt like this usually don't have a large
amount of silica in them. To get credit for this earthcache you
must note some observations about these rocks and how they hint at
how our mountains were formed.
Email me the answers to the
following questions:
1. The GC code and name of this cache.
2. The number of people in your group.
3. Based on the angles that the rocks are sticking up out of the
ground at, in what general direction did they come from?
4. Are the rocks shiny, suggesting that they came from lava with a
high amount of silica?
5. Based on your answers to question 2, does this support the fact
that they were spewn violently?
6. Granite forms when rock cools slowly, giving it a little lighter
color than some other igneous rocks, does the color of them suggest
that these rocks are granite or not?
