Exploring Sonoma County’s Varied Geology

Aug 9, 2015

The San Andreas fault is one of the most significant, yet unseen, geologic features in Sonoma County.

From deep underground to right out in the open, Sonoma County’s geologic heritage is varied and fascinating. A special series of hikes next weekend offers close-up looks at some highlights, with explanations from a knowledgeable guide.

Abandoned "quicksilver" mines can still be found in out-of-the-way corners of rural Sonoma County.

Another aspect of Sonoma County's recent geologic history--one that won't be featured in Melosh's transect hikes--is the mining that was active year in decades past. Evidence of that, especially for mercury, remains plentiful, but may be hazardous.

The geology transect is a benefit for the Sonoma Land Trust, and includes visits to several sites that have been preserved by the Trust.