GEYSERVILLE, Calif. -- A small earthquake has rattled a Northern California wine region where a huge wildfire is burning.

The United States Geological Survey says a quake with a preliminary magnitude of 4.2 struck at 12:34 p.m. Sunday near the Geysers.

A Sonoma County Sheriff's dispatcher says there have been no calls reporting damage or injuries.

The Geysers is the world's largest geothermal field, with power plants drawing steam from mountain wells to create electricity.

A wildfire that broke out in the area on Oct. 23 has burned 121 squares miles (313 square kilometres) of dry brush and timber. The blaze is 76% contained.