This EarthCache is reached via an unpaved road in an arroyo channel. Standard highway vehicles can reach the location with slow and careful driving in good conditions. There are a few sandy spots and some rocks to avoid. A 4x4 and high clearance is recommended at any other time and would make the drive out to the cache much quicker.
Here in the desert, water is present deep underground. However, in a few places the geology of the area forces the water up to the surface to create oases.
This oasis lies at the southern end of where the Clark Fault can be seen at the surface. The Clark Fault can be more easily seen off to the northwest as it cuts across the front of the Santa Rosa Mountains (see Alluvial Fan Ages).
Faults can either act a conduit or barrier for ground water. If the fault breaks up the rock or sediment creating a zone with lots of cracks, ground water will move more easily through the cracks. However, if the fault continues to break up the rocks turning them into a pulverized mess, the fault will actually act like a dam and ground water will mound up behind the fault. I do not know for sure which is happening here.
The amount of water coming out of the spring at the surface is highly variable (and not potable). One of the variables that determine the flow is the precipitation in the area. As part of the logging requirements you will compare the recent precipitation to the observed flow from the spring.
Logging requirements:
Send me a note with :
- The text "GC1026Z 17 Palms Oasis – A Fault Controlled Spring" on the first line
- Look up the precipitation for the past year in Borrego Springs and and compare it to the flow from the spring that you observe. Precipitaion, then click on history.
- Look toward the northwest and see if there are any features you can see to indicate the location of the Clark Fault. Do they appear to line up with the location of the spring? How does the shape of the spring suggest that it might be along a fault?
The above information was compiled from the following sources:
- Paul Remeika, personal communication via The Anza-Borrego Institute
- http://www.blm.gov/ca/elcentro/POI_borregovlly.html