Blue goo is a sticky, plasticky, blueish-grey, clay-textured soil derived from a highly weathered serpentinite mélange.[1][2] The name derives from the soil's color; a result of undergoing anaerobic conditions and becoming gleyed.[3] A greyer variation is called "grey goo".[2] Blue goo is primarily found along the Northern California coast.[2]
Parent material
The Franciscan Complex is the bedrock from which blue goo is derived.[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.[1][2][4][5][6] These materials mixed together forming a "plum pudding" or a mélange.[1][2] This mélange decomposed through weathering to form blue goo.[7]
Common features
Clay soils like blue goo have the highest water-holding capacity when compared with other soils, giving them a low draining capacity.[3] This kind of habitat is unsuitable for most plants,[3] but the Northern California coastline maintains high levels of vegetation year round.
Due to blue goo's clayey texture, it slips when overly saturated.[6] This slippage is increased in heavy rainfall areas and in shallow soils; deep soils have more total pore space and are not as prone to slippage.[3] These features contribute to the landslide-ridden environments found along the Northern Californian coast.[5][6]
Locations
The Franciscan Complex, from which blue goo is derived, extends from Central California up the coast through parts of Southern Oregon.[1] But blue goo has only been found in two Northern Californian regions located in Humboldt County: the Trinidad region and the Orick region. Blue goo is thought to also be found in the Eel River region and along the Southern Oregon coastline.