Eastern Washington Geology to da Max!

At first glance, Eastern Washington looks a lot like South Dakota in many places. There are miles of rolling prairie, covered with wheat. But there has been a LOT going on here geologically speaking. Now the Old Sloat is a meterorologist, not a geologist; but as a general rule, I think we 'ologists are all interested to some degree in each others' specialties. For starters, here's a classic shot of Mount Adams in Washington, rising above some of the aforementioned wheat fields. It's a fine example of a Cascade volcano. In fact, at over 12 thousand feet, it's the third tallest in the range, behind only Rainier and Shasta.

I visited the Lava Lands visitor center near Bend earlier this week, and found this book entitled "Glacial Lake Missoula and its Humongous Floods". I bought it, as I had been interested in the topic for a long time but had not read much about it. It's all quite fascinating; Google the Missoula floods and you'll probably find good info on it. Anyway, the main culprits in this series of geological catastrophes were the ice age glaciers. Beginning about 15 thousand years ago, they advanced into northern Washington, Idaho, and Montana. On the plateau between Lake Chelan and Grand Coulee the glaciers left thousands of huge basalt rocks from farther north. These are glacial erratics, a few of which are seen here sitting on the grass where they have been for millennia.

Here's a fine example of a single erratic lying in a field. The farmers just plow around it...it's about the size of a small house so is too big to economically move. Besides, it's a piece of geological history!