The Elder Creek ophiolite, which crops out along the South, Middle, and North Forks of Elder Creek, is the largest exposure of mid-Jurassic Coast Range ophiolite in the northern Coast Ranges of California. The Elder Creek ophiolite contains almost all of the components of a classic ophiolite (mantle tectonites, cumulate ultramafics and gabbro, dike complex, volcanics), although most of the volcanic section has been removed by erosion and redeposited in the overlying Crowfoot Point breccia. It differs from classic ophiolite stratigraphy in that it has substantial volumes (25%–30% of the complex) of felsic plutonic rocks intimately associated with the other...