California was formed by a series of subductions and other accretive processes, effectively bolting the coastal and Sierra mountain ranges onto the North American landmass. The author reviews the evidence in ‘northern California’, particularly the gold rush that is the most famous example, before ranging further afield (Arizona, Cypress, Greece) to elaborate the theory of plate tectonics. The paradise revolutionized the geology of Eldridge Moores, the book’s protagonist. Also contains an interesting analysis of earthquakes and their impact on the San Francisco-Santa Cruz region. At times too technical (for me), but in all an excellent survey and resource on Norcal topography.