In the movie "A River Runs Through It", the narrator ends with the following, one of my favorite quotes in any movie...
Then in the Arctic half-light of the canyon, all existence fades to a being with my soul and memories and the sounds of the Big Blackfoot River and a four-count rhythm and the hope that a fish will rise. Eventually, all things merge into one, and a river runs through it. The river was cut by the world's great flood and runs over rocks from the basement of time. On some of those rocks are timeless raindrops. Under the rocks are the words, and some of the words are theirs. I am haunted by waters.Because Norman Maclean's father was a Presbyterian minister in the 1920s, and his preaching and teaching was one of the ongoing themes in the book and movie, I assumed the referred-to flood was Noah's, but when I picked up the book, I was surprised to find that he was actually speaking about the Spokane Floods. My appreciation and respect for Norman Maclean jumped up many notches.
Geology, a science that embraces change more than any other, was caught in a form of stasis at the beginning of the 1900s. Geologists embraced the principle of uniformitarianism, the idea that we can learn of past processes by looking at those that are active today. It is in fact the founding principle of the science, but a hundred years after adopting it, geologists were trapped into a mental construction that required that all processes were the same, and that they operated at the same rate as they do today.
J Harlan Bretz was a high school science teacher in Washington state (later a professor in Chicago). He was mystified by elements of the landscape across the drainage of the Columbia River, especially a region that he called the Channeled Scablands. Numerous dry river channels and small depressions cross the high plateaus of basalt, carving up the windblown silt prairies into islands of fertile soils (the Palouse Soils). I posted an aerial photo of some of these silt islands here. In places, the dry channels were in deep canyons separated by long-dry waterfalls (the Coulees).
|Bretz wanted to know how this landscape...|
|...became this one...|
When he published papers on the subject in the 1920s, geologists were aghast. Giant floods covering the landscape to a depth of hundreds of feet were not a part of normal geologic thinking. It smacked more of religious catastrophism. And Bretz couldn't say where the floods had come from. But the evidence accumulated, and after only a few decades, geologists came to accept the model. Luckily, Bretz lived long enough to see his ideas accepted, and he was ultimately given geology's highest from of recognition, the Penrose Medal (geologists don't get Nobels). Other geologists even found the source of the flood, a gigantic lake in Montana (Lake Missoula) that formed as the tongue of a glacier blocked a river drainage. The floods occurred when the unstable dam collapsed, unleashing cubic miles of water across the Washington landscape.
That's where we were headed on the fifth day of our journey in the Pacific Northwest.
The rains of the previous day were gone and forgotten. The day was bright and clear as we headed north out of Yakima. Our first stop was Central Washington University in Ellensburg where we talked with the archaeologists who have been studying dating of human teeth, and who have been excavating the Wenas Creek Mammoth Site. Pat Lubinski took us on a tour of the lab where the fossil specimens have been laid out (the giant femur in Dr. Lubinski's arms is a lightweight cast, in case you were wondering).