Monterey Formations right here in Monterey!
Pick up a cache or two, then come down here and grab an Earthcache! The Monterey Formation can be found all throughout California mainly, but not limited to, Coast Ranges, Peninsular Ranges, off-shore islands, or previously submerged mainland. This formation is made up of clay, dirt, soil, silt, and rock. The Formation is also potentially a rich provider of oil for California, and has had its strata (layer of sedimentary rock) researched repeatedly and mapped for petroleum potential. But analyses and efforts have been largely unsuccessful in producing Monterey-hosted oil. The oil contained in these rocks is packed in tightly between the crevices, and can be difficult to extract. Its rocks are sedimentary, and can contain many examples of coastal fossils. More notable examples can be small crabs, kelps, and/or soft-bodied seaweeds. These sea plants are seldom seen as fossils in any other form of rock formation. With the information given, we can infer that this land was once submerged in water for a very long period of time. Being near the coast, it is not hard at all to imagine the coastline a little further in a long time ago, covering this part of the land.
The example of Monterey Formation seen here is a great reminder of the rich Geological History present in this area. The light-colored Monterey is rich in silica, and the rocks here include shale, porcelanite, and chert sometimes mixed with yellow-orange stains. The stains represent a metal (iron) that is present occasionally in the rocks. Being submerged in water, this metal oxidizes to an orange color while in the Formation.
To log this Earthcache as a find, please send an email with the following:
The name of this earthcache,
The number of people in your group,
And the answer to: Based on your Monterey Formation knowledge, is the metal of iron present in this specific sample?
Have fun!
Sources:
1. http://www.geocaching.com/geocache/GC2JWQ7_geo-lab-the-monterey-formation
2. http://en.m.wikipedia.org/wiki/Monterey_formation
3. http://www.ucmp.berkeley.edu/tertiary/mio/monterey.html
4. http://www.crystalcovestatepark.com/geologyguide112309small.pdf