Hiway16 Magazine... about people and places in north-central British Columbia, Canada

PAGE ONE
OF THREE

A Rocky Mystery

by Jim Easterday

Do you like a mystery story? You meet the characters, look at the evidence and then you must figure who did the dastardly deed. Fun!

There is a local mystery story all around you - on a monumental scale. The mystery is "...what shaped our mountains and our valleys? or "...what did our valleys look like years ago?"

A kettle lake (swamp) near Topley

The characters in our mystery are the forces of land building or geology. In our area, they include an exotic cast of volcanoes, tropical islands, huge lakes and glaciers. Let's investigate our glaciers.

Here's an example that's easy to see. Just south of Topley, the highway swings around a swamp. Within the last 12,000 years, that swamp was a large block of ice that broke free from the glacier that covered the entire Bulkley Valley to a depth of up to 5000 feet. As the glacier melted, it dropped gravel and sand on top of our big block of ice. As the block melted, the gravel slid down the sides of the ice to form a ring or hill of gravel in the exact shape of the ice block. The ice is gone but the gravel ring remains and is now covered with trees.

Another kettle lake between Topley and Houston

Along Highway16 toward Houston, there's another kettle lake. Of course, the lake water is gone and only a flat swamp remains.

All the flats near Topley are a massive dumping ground of glacial sand and gravel. The clays around Burns Lake and the gravels flats near Telkwa and Smithers are all the result of a mile-thick glacier that ground rock to flour and pushed gravel for miles along the valley, rounding hills and scouring out long narrow lakes.

The last valley glaciers melted about 8000 years ago. In geological time, that's almost yesterday. Which leads us to the next part of the mystery - what shaped our mountains?






copyright © 2001, Northwest Design, Smithers, B.C., Canada