Ever wondered what kind of stone comprises the Sonoma coastline’s majestic cliffs? Find out at the Fascinating Geology of the Sonoma Coast mini-lecture on January 14. The Facebook Live video is part of a series of 15-minute talks presented every Thursday at 2:30 p.m. on the Sonoma County Parks’ Facebook page. Additional talks include Winter Spawning Grounds (January 7); Out of Town Guests: Winter Birds (January 21); and Historic Flooding of the Russian River (January 28). Find out more at parks.sonomacounty.ca.gov and facebook.com/sonomacountyregionalparks/?ref=page_internal.