Blue goo is a sticky, plasticky, blueish-grey, clay-textured soil derived from a highly weathered serpentinite mélange.
[1] It stretches along the coastline from Central California up to Southern Oregon and contains sheared materials from both the Pacific and North American Plates that have accumulated in the accretionary wedge.
[1] The rock types that produce blue goo include: greenstones, cherts, basalts, shales, sandstones, schists, and serpenitites.
[3] This kind of habitat is unsuitable for most plants,[3] but the Northern California coastline maintains high levels of vegetation year round.
[5][6] The Franciscan Complex, from which blue goo is derived, extends from Central California up the coast through parts of Southern Oregon.