Chimney Rock's Roadside Cousin – Earthcache

A cache by PathfinderMark Send Message to Owner Message this owner
Hidden : 7/13/2009
In California, United States
1.5 out of 5
1.5 out of 5

Size: Size: other (other)

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Geocache Description:

There are a variety of pinnacle formations in the area between Alturas and Davis Creek CA, with Chimney Rock being the most popular of them. There is a pull-out right next to the rock, but be sure you pull ALL THE WAY off for your safety.

However, since many travelers would not feel it worth their time to drive the .45 miles each way on a dirt road to find Chimney Rock (or potential hike if the road is unserviceable), I have guided you to a roadside pinnacle that is of the same substance as Chimney rock -- not to mention, you can walk right up to it and touch it if you so desire. It is wheelchair accessible, except that the upper type of rock cannot be reached from a sitting position except on the back of the pinnacle, which is on bumpy ground.


The columns are made up primarily of extrusive Basalt rock overlaying a layer of sandstone. In this area, wind and a long-forgotten, long-gone sea (scientists believe that the pacific ocean used to have its beaches in Modoc County!) have worn away at the Basalt and underlying sandstone leaving “hard” pillars behind.

This basalt is part of what is termed the “Warner Basalt” and is considered part of the balsalt “region” that extends from eastern Washington, through most of eastern Oregon, south to Lassen and west to Lava Bed National Monument. This basalt is considered “flood basalt” meaning that the amount and coverage of this basalt is not just a mere few miles as would be common for basalt flows, but rather extends for 100s of square miles, indicating either one huge catastrophic event (meteor, LARGE flood, etc.) or to a series of plate movements (if you are traveling over to Cedarville, you might notice the 25 degree tilt of the Warner Mts. On the edge of the “block fault.”), that released a chain reaction that resulted in basalt being formed in copious quantities.

Basalt rock makes up the majority of world's oceanic crust. Basalt is fine-grained so that the individual minerals are not visible, but they include pyroxene, plagioclase feldspar and olivine.

Types of Rocks:
Sedimentary – Sedimentary rocks are formed by the “settling” and “solidifying” of sand/dirt/debris deposits and organic material (such as animals and plants). This process takes place on the earth's surface (unlike Igneous and Metamorphic rocks) and is largely thanks to the actions of bodies of water. Rocks from from sediments cover 75%-80% of the earths land area.

Igneous – Igneous rock is formed by magma (molten rock) being cooled and becoming solid. These rocks may form with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. Magma is derived from one of two sources – partial melting of the Earth's mantle or its crust. In an igneous rocks' history usually on a small portion of its life is spent in a magma state. The melting is cause by one or more processes: temperature change, pressure change, or composition change.

Metamorphic – Metamorphic rock is caused by the transformation of a exiting rock type (either sedimentary or Igneous) thanks to heat and/or pressure. Extreme heat or pressure (“weight”) cause the rock to change dramatically.

Logging requirement #2 requires this knowledge.

To log this cache:
Walk up to the pinnacle of rock, and compare the rock composition of the upper and lower portions of the pinnacle.
1.Describe the two types of rocks consistency or luster (do they look granular, shiny, greasy, transparent, milky)
2.Describe what type of rock you see (sedimentary, metamorphic, igneous) at the top of the pinnacle.
3. (Per current guidelines, photos are no longer allowed to be required. HOWEVER they are encouraged, since they can help clarify that you have visited the location if your other logging requirement answers are vague). Take a picture of yourself / group with the column clearly visible behind you. You may find it extra special to try to creatively include the “window” that is in the column.

NOTE: I do hope you'll take the 20 extra minutes to drive/walk over to the Castle Rock Historic Monument. It gives you a small taste of what Pinnacles National Monument is like!

Logging: Since the advent of the "new" Message the Owner feature, I prefer messages through that venue

I will only respond if you have incomplete logging requirements. Go ahead and log your cache

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151 Logged Visits

Found it 138     Write note 3     Archive 1     Needs Archived 2     Unarchive 1     Temporarily Disable Listing 1     Enable Listing 1     Publish Listing 1     Needs Maintenance 1     Owner Maintenance 2     

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Last Updated: on 6/14/2017 10:09:57 PM Pacific Daylight Time (5:09 AM GMT)
Rendered From:Unknown
Coordinates are in the WGS84 datum