At this point in the season – after Washington vines have been trimmed and before bud break – there is not much change that can be seen from the outside of the vine. All of the action is inside the vine, which makes one look around at other visible things, such as the soil, and wonder how it got there and its relationship to the vine.
During my April trip to visit DuBrul I talked to Hugh Shiels, patriarch of the Shiels family, owners of the vineyard, about rocks and the geological history that makes the DuBrul Vineyard. The vineyard is in eastern Washington, the area that owes much of its grape-growing ability to the Missoula Floods. In rock time, the floods are recent geological history. What about before the floods?
A few years ago friends gave me a copy of Roadside Geology of Washington, a book that lives in my vehicle next to the road atlas and winery maps. Luckily, this book is written for the lay person and nicely explains with both words and pictures how the state of Washington was formed in the first place, millions of years before the Missoula Floods. With apologies to the authors and geologists the world over here is the short version I carry around in my head:
After the single huge continent, known as Pangea, split into two millions and millions and millions of years ago, and the North American half separated from what became Europe and Africa, the large “Americas” mass kept moving west. This westward movement meant that the western coastline of this new giant mass would eventually collide with island continents floating to the west in what we know as the Pacific Ocean.
The original western coastline in Washington was around Spokane in eastern Washington not far from the Idaho panhandle. Then two hundred million years ago the first ‘island continent’, the Okanagan, collided and connected with Washington. The Okanagan area (central Washington) then became the western coastline. About 150 million years later the North Cascade micro-continent collided with Washington adding the third piece of the patchwork. This is how Washington became the land mass that it is – the original land mass and two micro-continents collided. When land masses collide the ocean trenches off the coastlines disappear and the continental rock in the trenches rise to create new mountains and act as welds making the collisions permanent, at least permanent to the current day.
During this time, and even after the three land masses had made one land mass, volcanic ranges came and went from different areas leaving behind lava basalt flows. The most impressive one we know as the Columbia Plateau in southeastern Washington. These basalt flows were great enough to change the course of the ancient Columbia River to what we know today. The climate went from tropical to dry and winds blew dust from the west to the east.
On top of this welded canvas came the ice ages. Large glaciers covered the northern 1/3 of Washington leaving behind till consisting of rock of all sizes from clay to boulders. These glaciers carved out the Puget Sound in northwestern Washington and the Okanagan Valley in north central Washington.
The last ice age about 13,000-15,000 years ago brought the Missoula Floods. In Montana, a giant dam of ice formed on the Clark Fork River creating Glacial Lake Missoula, a huge, huge lake. The ice dam is estimated to have been over 2000 feet tall, taller than two Chrysler Buildings stacked on top of one another. Under the pressure of the growing lake the ice dam ruptured and the lake emptied out flowing west across Idaho and Washington eventually finding the Columbia River and continuing its wild journey deepening the Columbia River Gorge as it flowed to the Pacific Ocean. The flood waters picked up and dropped more than 50 cubic miles of dirt and rock.
This was a cataclysmic, violent event. It is estimated that the volume of rushing flood water was greater than 10 (count ’em 10) times all the rivers in the world and traveled up to 80 mph. This flooding did not happen just once or twice but possibly as many as 40 or more times over a couple of thousand years. Each flood moved massive amounts of loess, sediment, boulders and basalt.
My two vines, DuBrul and Hollywood, reside in two different parts of Washington.
Two parts of Washington that share some, but not all, of the geological history of the land inside the geo-political boundaries of the state. What is the soil beneath each vine and how did it get there? Was it deposited by a volcano, a glacier, dry westerly winds or a flood?
Stay tuned for the answers from the vineyard owners.
Note: Bloggers attending the 2010 Wine Bloggers Conference in Walla Walla, WA – If you are traveling east through the Columbia Gorge and then northeasterly to Walla Walla you will see many flood features as this is essentially the flood path in reverse.