Sunday, September 1, 2013

Newberry National Volcanic Monument

Our second day in central Oregon was spent looking at different features of this caldera.  Newberry Monument is the largest volcano in the Cascade arc, covering an area about the size of Rhode Island.  It has two deep lakes and lava flows of pumice and obsidian.  Our first stop was at Lava Butte.  John spent his time there at the Visitor's Center looking at all the exhibits which had way more information on the monument than I had the patience to read.  After a few minutes there I headed out to explore the fields of lava which surrounded the building.  It reminded me a bit of Craters of the Moon.
You may notice in the picture above a very twisted tree.  Someone with a sense of humor dubbed such trees as "Lava Ness Monsters.   From the visitor's center we drove to the summit of Lava Butte. There we had a good view of a volcanic caldera.  Depending on mineral distribution within the rock and atmospheric conditions lava cinders can be found in red or black.
The most spectacular lava flow in the Newberry Volcano is the Big Obsidian Flow, which is 1,300 years old.  Usually the rock one sees in lava flows is pumice.  Obsidian is a liquid that has cooled before crystallizing-  there are striking differences from rock to rock due to the number and size of the bubbles which are present during its formation.  We hiked up to the summit of the Obsidian Flow and could easily see the black shiny rock which lay mixed in with the pumice. The obsidian and pumice of this lava flow contain 73% silica, like most window glass does.
While hiking on this trail we met up with a couple from Liverpool, England.  John had questions for them about the Beatles, which led to quite a long conversation with them.  From the summit of this lava flow we could see Pauline Lake, one of the two lakes within the Newberry Monument.  It and East Lake have hot springs with temperatures as high as 135 degrees Fahrenheit, and in 1981 temperatures higher than 500 degrees were found in a geological survey. These temperature measurements indicate that Newberry is a high threat volcano.
Returning home we went over McKenzie Pass, which brought us back to the western side of the Cascades.  Unfortunately storms were moving in and a heavy cloud cover prevented us from seeing much of the Cascade range.  At the summit we explored a rock tower built by the Civilian Conservation Corps.  Each window in the building provides a view of one mountain, and the name of that mountain is written above the window. It was getting quite cold and windy by this time and the tower was a warm place to take one final look at the mountainside before heading for home.

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