Thursday, April 2, 2015

Geo 1095: March 30, Day 819: Coolly Incandescent

This was a crisp, but sunny, fall day, with temperatures in the low sixties, but the vine maples were incandescently glorious. Combined with the sunshine, we didn't feel the least bit chilly. In the upper portion of the photo, just below the rotting logs, you can see some of the fresh (~3 ka) basalt flow. The logs and the flaming foliage about to drop generate various organic acids as they decompose, which contribute to the slow but inexorable chemical weathering of the rock. In addition, the decomposed organic material serves as a source of nutrients and a moisture reservoir that will sustain future generations of plants. At this point, rain and snow melt percolate directly down into the rubble, and flow as ground water to Clear Lake a few miles south of here, where the water emerges as the head of the McKenzie River. Plants, past, present, and future, will eventually block much of the permeability in the ground here, along with the slow accumulation of weathering products from the lava. Barring new flows from close by, in a few hundreds of thousands to maybe a million years, there will likely be a gorgeous babbling stream in this location. However, given the recent history of the area, it's more likely this area will be repaved with new flows, and the process will start all over again.

Photos unmodified. October 9, 2012. FlashEarth Location.

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