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Log Rock Earthcache
The Log Rock is located in Kingdom Come State Park in Harlan County
Kentucky near the city of Cumberland. It is a natural sandstone
bridge that was formed from years of erosion due to the weather.
Log Rock gets its name because it greatly resembles a petrified
tree which has fallen over. Unfortunately, the Log Rock has been
severely vandalized over the years, and the underside is now
covered with people's names that they have spray-painted or
scratched onto the stone.
Weathering Agents
No matter the type of arch found in Kentucky, each are shaped by
the process of weathering. Weathering can be tought of as the
destruction of the rock. The primary agent is water, which seeps
into cracks and dissolves the iron oxide in the sandstone and the
calcium carbonate in limestone. Iron oxide acts to hold or c"ement"
the adjorning rock togeter and its removalresults in this
breakdown. Similar to water, plant roots find their way into
crevices and split the rock. The wind works to remove the broken
rock from the area.
What is Sandstone?
Sandstone is a sedimentary rock composed mainly of sand-size
mineral or rock grains. Most sandstone is composed of quartz and/or
feldspar because these are the most common minerals in the Earth's
crust. Like sand, sandstone may be any color, but the most common
colors are tan, brown, yellow, red, gray and white. Since sandstone
beds often form highly visible cliffs and other topographic
features, certain colors of sandstone have been strongly identified
with certain regions.
Rock formations that are primarily sandstone usually allow
percolation of water and are porous enough to store large
quantities, making them valuable aquifers. Fine-grained aquifers,
such as sandstones, are more apt to filter out pollutants from the
surface than are rocks with cracks and crevices, such as limestones
or other rocks fractured by seismic activity.
What is Erosion?
Erosion is displacement of solids (sediment, soil, mud, rock and
other particles) usually by the agents of currents such as, wind,
water, or ice by downward or down-slope movement in response to
gravity or by living organisms. There are two different types of
erosion "mechanical erosion" and "chemical erosion" Each of these
has a different effect on the environment. Mechanical erosion would
include water, wind, sun, ice, natural disasters such as
earthquakes and shoreline erosion. Chemical erosion would be acid
rain, over use of fertilizer, human land use, deforestization and
overgazing.
A certain amount of erosion is natural and, in fact, healthy for
the ecosystem. For example, gravels continuously move downstream in
watercourses. Excessive erosion, however, does cause problems, such
as receiving water sedimentation, ecosystem damage and outright
loss of soil.
Logging Requirements:
In order to receive credit and keep that smiley face for your find,
you must do the following. Failure to do so will result in the
deletion of your log.
1.Take a photo of the finder with their GPSr visible in their
hand with the Log Rock showing in the background.
2.Estimate how wide and long the Log Rock is. It would be best
to take the steps to the Log Rock to answer this question.
This Earthcache was approved by the GSA