The California Coast Ranges preserve an exceptional geologic archive spanning subduction, accretion, strike-slip deformation, and magmatism, and serve as a natural laboratory for understanding the evolution of plate boundary systems. This session invites contributions that investigate the transition from Mesozoic subduction and construction of the Franciscan Complex to the Cenozoic development of transform tectonics associated with the San Andreas Fault System. We welcome studies that explore the processes governing this transition, including deformation mechanisms, strain partitioning, magmatism, basin development, and the role of inherited structures in shaping later tectonic evolution. Contributions that integrate bedrock geology, structural geology, and stratigraphy with geophysical imaging, geodesy, geochemistry, paleomagnetism and geochronology are particularly encouraged. Topics may include: accretionary processes and mélange formation; exhumation histories and pressure–temperature–time paths; structural controls on deformation and fluid flow; development and evolution of strike-slip fault systems; basin formation and sedimentary records; and volcanic–tectonic interactions in convergent and transform settings.