Dating real jerks.(lichens reveal prehistoric earthquake record)(Brief Article)

Fungus coatings on rock pin down quake ages.

Rock-loving lichens seem an unlikely storehouse for earthquake information. But two geologists are using these tiny plants to reveal the prehistoric record of major tremors. And this novel approach is changing what we know about earthquake cycles. The info gleaned from lichens along California's San Andreas fault, for instance, suggest that the next big one may come sooner than expected.

Large quakes knock lots of rocks loose, causing rock slides as far as 250 miles from the earthquake's center, says Mark Brandon from Yale University. The slides expose fresh rock surfaces, and lichens like that. They quickly begin …