Photograph from Parking lot viewpoint. Note Kame, hilltop to your left.
There have been many glacial stages during the last 2 .5 million years. The last large glacial advance in the Rocky Mountains started about 25,000 years ago and referred to as the Fraser Glaciation. The main ice centre was in central BC where the ice sheet was over 1 kilometere thick and the glacier flowed in all directions. A glacier flowed southward through this valley during the last ice age, advancing as far as Polson Montana (about 90 miles from Eureka). It retreated northward during the warming and by 11,000 years ago the valleys of southern BC were ice free.
As the glacier retreated blocks of ice calved from the front and these were then covered with debris containing till of boulders, rocks pebbles, clay and sand. This outwash became finer particles the further from the melting outwash. As the ice blocks under this sand melted the the sand collapsed leaving a depression ie a kettle. A kame was created in the reverse order ie a hollow from the melted ice was filled with the sand and thus a little hill was left behind.
kettles normally have no inlet or outlet but are natural wells fed by groundwater filtered by the silica rich grit free sand. During flood conditions Hanson Creek will allow the inflow from the Kootenay River. Wasa is below the water table and lake levels are largely governed by the neighboring Kootenay River. Wasa Lake was historically named Hanson Lake and is advertised as the warmest lake in SE BC. Bring your bathing suits.
This schematic is from Prof A.S. Trenhaile University of Windsor shows a profile of the Rocky Mountain Trench
Acknowlegements to: B.C. Pearce (Geological Field Guide to The Southern Rocky Mountain Trench; E Swanson, College of the Rockies Ben Gadd, handbook of the Canadian Rockies
To log this Earthcache, please email the owner with the following: a) the height of the sand dune (Kame) b) would you expect the lake level changes to be significant from late spring to late fall? Why and how much? c) Although the lake is on a bowl of sand it does not drain. Why? d) This lake is very large compared to most kettle lakes and maybe because it was the result of a couple of melting ice blocks. What may be the largest number of possible blocks.?
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