This earthcache highlights two features of the sierra foothills.
A fault is a geologic feature that is a fracture in a volume of rock.
When the Sierra Nevada Mountains were pushed up by a combination of fault action and volcanics about 130 million years ago, they were pushed up against the central valley. This is what caused the low lying hills we call the foothills to form. At this location we can observe one of the faukts that formed the sierra and sedimentary layering from the formation of the central valley (for more information see GC2HJPM). What's strange about this location is that these formations would not have been able to be seen if not for man's cutting away the hillside here that exposed these formations.
There are three main kinds of faults: normal, strike slip, and reverse. Each type of fault gets its name from the way that they respond to pressure. A normal fault is when the fault slips and one side of it is forced down from the other piece. A reverse fault is exactally the opposite of this. With a reverse fault one piece is forced up over the other one. There is little difference is physical appearance between normal and reverse faults, the main differencee being how they move. A strike slip fault is when the two pieces grind and push themselves past each other, an example of this is the nearby San andreas fault.
This fault is actually somewhat hard to see because it lies within layered sediments from the formation of the central valley from an inland sea. However, it is easy to tell that they have been acted on by some force because of the angle at which they are compared to the flat bottom of the sea they used to lie on.
To get credit for this earthcache 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. Using the provided diagram, what kind of fault is this?
4. What angle from horizonal is the fault at?