Stone columns, Crowley Lake, California

The strange pillar-like formation emerged after Crowley Lake reservoir was completed in 1941: stone columns up to 20 feet tall connected by high arches, as if part of an ancient Moorish temple. 

They had been buried and hidden for eons until the reservoir’s pounding waves began carving out the softer material at the base of cliffs of pumice and ash... 

Researchers have determined that the columns were created by cold water percolating down into — and steam rising up out of — hot volcanic ash spewed by a cataclysmic explosion 760,000 years ago... 

The columns began forming as snowmelt seeped into the still hot tuff. The water boiled, creating “evenly spaced convection cells similar to heat pipes,” according to the study to be presented next month in San Francisco at an American Geophysical Union meeting, the world’s largest conference in geophysical sciences.

More information at the Los Angeles Times, whence this video -

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