| Abstract/Description or Keywords |
The Quaternary South Thompson Silt, which occupies the bottom of the valley of the South Thompson River, accumulated in a late-glacial lake formed between retreating ice tongues. It contains varves and sedimentary structures related to melting of buried ice, drag of floating ice, and simple gravity movements. The thickness of the varves is as much as 250 inches in the lower part of the unit and grades upward to about 1 inch in the upper part. The silt was derived largely from erosion of till on adjacent uplands. Similar silt units occur in other valleys of the Cordilleran region. |
