Silt Bluffs EarthCache
-
Difficulty:
-
-
Terrain:
-
Size: 
(other)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
Sediment and Deposit Bluffs Along the South Thompson River Valley
As you drive along Trans-Canada Highway #1 between Kamloops and Chase, B.C., you may notice the interesting bluffs that parallel the South Thompson River. These unique bluffs are visible on both sides of the river for nearly fifty kilometers. The safe viewpoint we’ve selected is a highway sign near the Billy Miner truck stop that tells of a historical figure in past valley history.
About 17,000 years ago, the South Thompson River Valley in British Columbia was occupied by an ice-dammed lake. In time as the glacial ice melted, the water drained and silt collected from the highland areas, known as “montane”. That silt slowly settled into the river bottom and adjacent slopes, creating what is known as “loess”. Loess is sediment formed by the accumulation of silt and debris.
Eruptions of Mt. Mazama and Mt. St. Helens between three and seven thousand years ago blew more granular material that settled in layers into the loess, providing scientists easy markers to study the age and composition of the bluffs and river bed. Now, the loess in the central part of the valley averages 4 meters thick but becomes thinner as it rises up the slopes of the bluffs. The South Thompson River wind-flow patterns provide data as to where and how the accumulations of silt and sediment occurred.
As you look south from where you are standing, you can see some of the formed bluffs. You may desire to take one of the roads up to them for closer examination and to run your fingers through the silt.
To claim this earth cache, send the answers to the cache owner listed above before listing your find:
1. What is “loess”?
2. As you look at the Silt Bluffs, what is their predominant color?
3. What two mountains played an important role in these formations?
4. How many years ago was there an ice-dammed lake in the South Thompson River valley?
5. If you care to, please submit a photo of the bluffs with your GPS.
NOTE: Be aware, there is a traditional cache at the same location (Bill Miner 1).
Additional Hints
(No hints available.)
Treasures
You'll collect a digital Treasure from one of these collections when you find and log this geocache:
Loading Treasures