MOUNTAINS: Rock stars' history

The article “Hiking Chilco Peak” (Jason Wilmoth) brought back fond memories of seeing elk, moose, white-tail deer, mule deer, wolf tracks in the snow, gray jays gliding by, grouse, and more on that mountain.

Another dimension is the earth history. There are water ripple marks in the mudstones, suggesting that the muds were deposited by water coming from the southwest. The deep saddle on Chico may be a “water gap,” where later trapped water breached still soft muds and left the land, as the area began to be uplifted.

This mountain is part of a mountain system, including Glacier National Park, that ranges up into Canada. When you have a steak at Wolf Lodge you are sitting on these rocks. The basalt layers in the mudstones near your table have minerals, suggesting much water intake; plus, you are sitting on a 300-mile fault traveling into Montana.

For many geologists it has been puzzling as dozens of clues suggest that the sedimentary rocks and interlayered basalts were formed rapidly. Most rock layers (formations) have no erosion between them and are hard to map. There are all kinds of phenomena suggesting that trapped water and gases were under great pressure, and exploded upward (liquefaction) — a catastrophic environment.

And there is even evidence of shatter cones from solar system impactors “colliding” with the sediments.

These 50,000-foot thick rocks should not be confused with the younger Missoula Flood Ice-Age catastrophic deposits.

These beautiful layered rocks are gray, black, green, red, purple and orange (weathered). These rocks contain our fabulous Silver Valley Mining District.

JIM PEARL

Geologist

Hayden Lake