Long Valley Caldera

Glacial Features in the Long Valley Area, California

 

Glaciers have played an important role in modifying the landscape of the Long Valley area before, during, and after the enormous caldera-forming eruption 760,000 years ago.

Top of the basalt columns showing the classical hexagonal shapes, f...

Top of the basalt columns showing the classical hexagonal shapes, fine polish and glacial striations.

(Public domain.)

Glacial striations, moraine deposits beneath the town of Mammoth Lakes and in major river valleys, jagged cirques, and ice-rafted boulders scattered on ancient shorelines of the large lake that once filled the caldera are clear evidence that several episodes of recent glaciationoccurred here.