Introduction

Introduction

The Franciscan Complex refers to a group of mixed up rocks (mélange) that are found in western California and make up the Coast Ranges of central and northern California.
The complex has three belts: the eastern, central, and western belts, with increasing metamorphic grade and age to the west.
Ranges in age from 40-160 Ma.
Formed as the Farallon Plate Collided with the western edge of the North American plate.
Bounded by the Great Valley to the east and by the San Andreas fault to the west.