The conference is seven days of field trips, workshops, talks, and posters at Sonoma State University. I will be giving a poster and a full day workshop. The first trip examines world-famous exposures of the Franciscan Complex in Marin County to discuss subduction-accretion processes, high pressure metamorphism, and melange formation. These are ribbon cherts, one of the common components of the complex.

 

Held every two years at various locations in the U.S., the conference attracts workers in structural geology and tectonics. Most attendees are from North American universities, but industry and other continents are represented, and the research topics are international. Here we examine some highly disrupted melange.

 

Chevron folds in Franciscan Complex ribbon cherts exposed in the Marin Headlands.

 

Discussing high pressure metamorphic blocks in the Franciscan Complex at Ring Mountain.

 

The exposed blocks or "knockers", weathered out of the softer melange matrix, are popular bouldering sites.

 

On the final day of the conference I attend the "Brewschist" field trip, which highlights more of the Franciscan Complex, including magnificent outcrops of high pressure blueschist. The relative roles of deformation and sedimentation in melange formation has been debated for decades, here is melange fabric in a highly deformed serpentinite.

 

Discussion of the inferred tectonic environments and history continues with van-side illustrations.

 

Geologists are accustomed to working in precarious environments, but today we exit from the "danger zone" to higher ground.

 

The discussions continue under the well deserved shelter of several excellent brewpubs.