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Archive for the ‘Geology of Cascadia’ Category

 
 

Glacial Lake Missoula

Before you search Cascadia for the great healing plants, you should understand the lay of the land. What formed this amazing place?  What kind of soils and geology will you encounter as you hike through its forests, valleys, and high deserts? 

 

 

Why should you learn the geology of a place?  Why understand the lay of the land? The benefits are manifold:

-          You will know where to find the plant communities

-          You will not get lost in the woods or the mountains or the desert; you will be able to find your way from any point on the land

-          You will know how to find food, water, and shelter when you need it

-          You will see wonderful things and will not be afraid to wander in paradise. You will remain open to adventure, and you will encounter unusual plants within their communities

Where else on Earth could you live near an ocean, active volcanoes, coniferous rain forests, high deserts, marsh lands, sea estuaries, fertile valleys, high mountain glaciers, and so much more?  The Cascadian bioregion is a place of earth, water, and fire.  It is a place whose geology is new, old, and ever forming.

Plant life here is diverse and often unique. Many plants have adapted to wide swaths of this land; others are to be found in areas so small that they are in danger of disappearing off of the Earth.

What Geological Forces Shaped the Cascadian Bioregion?

Cascadia stretches from British Columbia to northern California to the north and south and includes Idaho and Western Montana to the East. On the big scale, it is being formed by the constant tension between two geological plates that are part of the Earth’s crust.  One plate stretches out into the Pacific Ocean moving eastward and is being pushed up into the land mass (Coast Range Mountains) toward the Cascade Mountains.  The other plate is moving westward and reaches deep into the hot, molten earth which is constantly forming the Cascade Mountains.  Between the two mountain ranges are valleys shaped by yet more geological forces.  This process is so dynamic that it is being created right in front of our eyes. This mountain range–valley–mountain range scene only covers one-third of the states of Oregon, Washington and Northern California.  The other two-thirds–now this is going east as the crow flies–is mostly high desert. There are some other mountain ranges to the east of the Cascades like the Wallowa and the Steens, but the plant life there is very different than the western third of Cascadia.  The eastern part of these states is a place of pine, hemlock, and juniper forests. People in other parts of the world seem to have the idea that Cascadia is all about Douglas firs, the Pacific Ocean, and the fertile farm valleys.  However, the area is diverse in plants and animal life, geology and hydrology.

Valley Floods

In Cascadia the western valleys were formed by old and new geological forces.  The valleys were formed somewhat by old rivers meandering through the soil levels.  Another amazing force was the periodic catastrophic floods.  These were floods in which 300 foot walls of water careened down valleys and river gorges, carving out new geologic formations and leaving behind vast layers of huge boulders, rock, minerals, and sand and gravel pits.  The First Peoples of Cascadia had many myths about the floods.  One interesting book that provides examples of these myths was written by Ella Clark called “Indian Legends of the Pacific Northwest”.  Clark reports that many of the creation myths of people of the region included stories about wildlife escaping the floods that renewed the area and then the animals and trees and plants helping the humans to survive and thrive. In these myths the animals help the Creator plan the world by using floods to shape the region. Here is link to a website that stores many indigenous people’s creation myths.  http://www.indigenouspeople.net/legend.htm

The Missoula Wash – the great floods of the region

If you go up on Mary’s Peak, located in the central part of western Oregon, you can look out over vast parts of the Willamette Valley.  You will see a place shaped mostly by the meandering Willamette River.  However, every once in a while you will see mounds–big, round mounds.  For a long time it was thought that these mounds were formed by Native Americans depositing shells or dirt for burial grounds.   In the 1920s scientists started to investigate the possibility that a great flood had occurred in Cascadia.  The flood, called the Missoula Wash or Missoula Flood, occurred thousands of years ago when a great glacial lake near Missoula, Montana, burst its seams.   Imagine a wall of water 300 hundred feet tall surging down the Columbia Gorge and then into the Willamette Valley.  What a sight that must have been! This was not one event: the glacial lake burst about every 50 years and made for some really exciting times in the valleys of Oregon and Washington. These floods deposited sand, gravel, and other mineral deposits throughout the area, and left large boulders throughout the Willamette Valley. 

After each ice dam rupture, the waters of the lake would rush down through the Columbia River gorge of eastern Washington and the Willamette Valley of Western Oregon. It took 40 to 50 years for restoration of these areas. Geologists estimate that floods occurred approximately 40 times over a 2,000 year period roughly 15,000 to 13,000 years ago.

Up until about 100 years ago, many of the valley areas of western Washington and Oregon were a series of lakes and marshes.  Anglo pioneers drained and filled in many of the lakes and marshes to create the farmland that is in the valleys today.  Many valuable plant communities were driven to the edges of the valley, and some plants can no longer be found in the area.  Camas, a staple food for native peoples, once graced the old marshlands.  There are few of these plants to be found in the marshes and sloughs of Willamette Valley (including Portland) today. Now many of the area’s camas plants live in very polluted waters. Native peoples did not live year-round in these valleys, because they could have caught malaria or tuberculosis.  They did, however, build seasonal shelters from plants, so they could fish and collect valuable foods and healing plants.

The Coast Range Mountains

The Coast Range Mountains extend from British Columbia to northern California.  The mountains are old and worn away by erosion and time.  They were formed by forces that pushed land up off the ocean floor, and it is not uncommon to find sea fossils and other sea sediments in this mountain range.  Up until about 75 years ago, the area was a vast and beautiful rain forest.  Much of the Coast Range has been clear-cut in the Cascadian bioregion. Many wonderful plants have been lost, because the fragile soils have been washed away by erosion and lack of a supportive ecosystem. Because the soils are old, they lack certain essential minerals needed by plant communities. Many humans who live in these mountains often have bad teeth because of lack of minerals.  Farmers and gardeners must add minerals (glacial rock is a wonderful source of these minerals) to help plants grow.  In the past the forests were kept healthy because of migrating salmon, steelhead, and other sea-run fish.  The spawning fish would swim up the streams, die in the river bed, and provide excellent fertilizer for the forest floor.  The sea -run fish helped plants to thrive.  It is getting harder and harder to find certain very valuable plants that once flourished in the Coast Range, because the fish are disappearing from the streams.

The Coast Range Mountains are not particularly tall compared to the Cascades Mountains, but there are a few larger mountains spattered along the Coast Range. And their height is important, because the taller Coast Range Mountains provide habitat for plants normally found only in the western slopes of the Cascades.

Some of the more important Coast Range Mountains habitats  are found at  Mount Olympus on the Olympic Peninsula, Mary’s Peak (Tamanawis) near Corvallis, Oregon, Mount Ashland near Ashland, Oregon, the Siskiyou Mountains and the Klamath Mountains in southern Oregon,  and the Trinity Mountains of northern California.

The lost world

One of the most important and unique places in the Cascadian Coast Range is the Kalmiopsis Wilderness Area.  There is no other place in Cascadia where you find more diverse, unusual, and important healing plants.  Walking through this area will make you feel like you are visiting another planet.  Even the soil is different. Much of the soil is of the Serpentine type. The hard bluish rock soil often found near perioditite rocks organizes itself in layers and is rich in heavy metals such as magnesium, iron, chromium and nickel, which in high amounts, can be toxic to most plants.  Plants and animals found in this area of Southern Oregon are often unique to the area.  And many of the trees and plants in the area need periodic fire to complete their life cycles.

The Cascade Mountains

Highly volcanic and very alive, these mountains provide much drama for both plants and humans. The Cascades are part of the Pacific Ring-of-Fire, the volcanoes and associated mountains that circle the Pacific Ocean. All of the known historic eruptions in the contiguous United States have been from Cascade volcanoesThey are large and snowcapped in the winter, and some still support glaciers.  In the summer melting glaciers and snowmelt create the beautiful lakes, rivers and marshes of the region. The snowmelt is also the main source for drinking water in the region. The wilderness around these mountains provides a safe harbor for the diverse plant communities that have offered food, clothing, healing, and shelter to humans and other creatures for thousands of years. Each mountain has its own energy but shares with other Cascade mountains similar soils, weather, and plant communities. 

This essay was originally written for Portland Indymedia as a skillshare on January 27, 2008. 

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