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]
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]
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]
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.