Here is a great example of a cinder cone. This is called the Fish Springs Cinder Cone, as it lies along the Fish Springs Fault. The cinder cone we are standing near is one of 30 or more in the 400 square mile Taboose-Big Pine volcanic field. There are several nearby major volcanic fields. The major local ones are the Taboose-Big Pine Volcanic Field (which you are in at this earthcache), the Darwin Volcanic Field, the Coso Volcanic Field, and the Ricardo Volcanic Field.
A fault scarp (scarps covered in this OV/ML Earthcache) cuts the toe of this specific cinder cone. As a result, it is offset by more than 25 feet vertically on the west side of the cone. Also on the west side of the cone, near the scarp and at the base of the cinder cone, is the Fish Springs Fault line one can view clearly. Most of the cinder cones in the Big Pine Field are comprised of red pumice. Pumice (also called scoria) is formed with volcanic activity and contains so much air, that is almost always can float in water. Most of these Owens Valley cinder cones lie along the east or west side of the valley, near the mountain fronts.
The formation of a cinder cone is caused by the particles and blobs of congealed lava that are ejected from a single vent in the ground. The gas-charged lava is blown into the air, breaks into small fragments (cinders), and falls around the vent to form a circular or oval cone. Cinder cones have the classic volcano feature of a bowl-shaped crater at the apex, yet they rarely rise more than a thousand feet above the surroundings.
Although cindercones are mostly composed of loose cinder and pumice, many of them are surprisingly enduring features of the landscape because rain falling on them sinks into the highly permeable cinder instead of running off down their slopes to erode them.
The elevation of the middle of the crater atop the Fish Springs Cinder Cone is approximately 4136 feet.
Log this Earthcache!
Send a note with the name of this OV/ML Field Trip EC
1) Based on your view, is this a circular cone or an oval cone?
2) Cinder cones rarely rise over 1000 feet. Let's put that to the test! Using the information given and your GPSr, find the height of the cone (elevation of the summit of the cone - the elevation of the bottom of the cone).
Sources:
http://geology.csupomona.edu/docs/sierra.html
http://www.pitt.edu/~cejones/GeoImages/2IgneousRocks/IgneousTextures/8PumiceScoria.html
http://www.britannica.com/EBchecked/topic/118008/cinder-cone
http://pubs.usgs.gov/gip/volc/types.html