The best hidden secret around. It all began 10 million years ago
when volcanic fissures spewed extremely fluid lava from eastern
Oregon. In a matter of days, the low viscosity lava flowed
northwards, covering everything in it's path. Then it stopped, and
then it started again - hundreds of times. These episodic eruptions
lasted for years and resulted in layers up layers of basalt
deposition in Eastern Washington and Oregon.
As the lava spread across the land, it filled the valleys,
transforming a once rolling landscape into a perfectly flat
plateau, Over time, rivers began to slowly cut through the basalt
layers creating new valleys and leaving behind upland plateaus.
If nothing had happened in the last 6 million years, you'd see
things just as the now extinct mammoths, bison antiquus, and
rhinoceroses probably did. But things changed. Approximately 2
million years ago, the climate became cooler, and glaciers began to
cover the northwest. As they grew, the ice blocked rivers and
dammed huge lakes behind them. Eventually these ice dams broke,
sending catastrophic flood waters over the land - from Missoula,
Montana to Portland, Oregon. The last giant flood to pass through
Escure was approximately 13,000 years ago.
"Rock Formation"
Rock Creek and its steep cliffs were formed as the water eroded
its way through the basalt rock. Giant ripple marks formed and
gravel bars were deposited underwater. Strong currents plucked
chunks of basalt from the ground, leaving behind deep round lakes,
scour holes, coulees, and irregular buttes scattered across the
landscape.
Resources: Signs at the posted coordinates.
Visit the interpretive sign at the above coordinates.
Your lesson will begin here.
To claim this Earthcache you will have to
answer the following questions and email me the answers. Please do
not post answers in your log, If answers are posted, your log could
be deleted without warning. Thank you!
1. Layers and Layers of what type of a
rock was deposited in Eastern Washington and Oregon?
2. How long and wide was the
Cheney-Palouse scabland tract?
3. How high was the flood when it came
through this area and How fast was it going?
4. Please visit (N 47° 00.843 W 117°
56.662) approximately 150 feet away. Please determine how fast the
creek is going in "Feet Per Second". To do this, throw a stick into
the creek, time the distance it takes to go a certain distance. To
calculate Feet Per Second you will need to divide the distance by
time.