Wednesday, August 21, 2013

Geo 365: August 21, Day 233: Little Nash Crater

How's that for some vivid color? On the drive back toward the Upper McKenzie basin, we stopped just past Santiam Junction (Where Route 22 merges with 20), at Little Nash Crater. This is another cinder cone in the same line as Sand Mountain, which is almost certainly fault controlled. In this case, though, the cinders are being actively quarried and processed for gravel roads and for cindering the pass areas in winter weather. Many of the Cascade high-elevation highways have red berms as a result. Cinders give traction in ice and snow, without the negative effects of salt. Additionally, the sheer quantities of snow that can fall in a single storm would overwhelm even the most determined salting campaign.

It's kind of cool to be able to see a cross section of the volcanic stratigraphy here. I don't have references at hand, but I think this is the source of the lava flow at McKenzie Junction, which I discussed back in January, here and here.

Photo unmodified. August 11, 2013. FlashEarth Location.

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