Thursday, September 11, 2014

Geo 730: September 10, Day 618: Fire and Water

A nice conclusion to the vein photos, the fiery red of Aaron's hair along with the watery blue of Dana's clothes combine to create the quartz vein directly between them. Of course, "fire" is figurative in this case; the heat was supplied by the diorite intrusion we saw at Yellowbottom Falls, and the "water" was a hydrothermal fluid, well above the temperature we think of as boiling, but under enough pressure to keep it liquid. It would've hardly been perceived as a cool blue. The temperature we call boiling, 100 C, is only "boiling" at standard atmospheric pressure. Higher pressures mean higher boiling points, lower pressures mean lower temperature. So the same physical processes that deposited this vein also necessitate the need for high-elevation cooking instructions for some foods. Cooking pasta at Yellowstone National Park takes longer than it does here in the Willamette Valley, because YNP is 2-2 1/2 kilometers higher in elevation.

Photo unaltered. July 9, 2012. FlashEarth Location.

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