By Lupa
[Snip] First, I need to explain what I mean by geological totems. A geological totem is the presiding spirit of a given specific geological phenomenon. It is not defined solely by a specific type of stone, or a single landslide, but instead is more a conglomerate of forces coming together to create a particular phenomenon, like a canyon or a mountain or watershed. And they overlap quite a bit, too, to the point that, like sediments turning into sandstone, their identities can merge into one even as the individual grains are still perceptible.
The Columbia River Gorge is a very good example. The oldest rocks are from volcanic activity 40-20 million years ago. The high walls of the Gorge are made of dozens of layers of basalt, which formed 15-10 millions of years ago from incredibly large lava flows. Volcanoes around what is now the border of Idaho and Oregon produced so much lava that eventually the basalt was over a mile thick in places. Even more volcanoes erupted to create the Cascade mountain range 2-1 million years ago; the Columbia River flows through these mountains. And as if all that volcanic activity weren’t enough, 16,000 – 14,000 years ago all that volcanic matter was carved and sliced and ground into the Gorge we know today–by massive flood of water. The enormous Glacial Lake Missoula, created by meltwater from glaciers at the time, would periodically flood, sending walls of water up to several hundred feet high down the course of the Columbia, deepening and widening its bed.
What’s been said…