Serpentine soils

Serpentine soil is mostly derived from ultramafic rocks; In particular, serpentinite, a rock formed by the hydration and metamorphic transformation of peridotite. Peridotite is an ultramafic rock from the Earth's upper mantle. Serpentinite is composed of the mineral serpentine; the two terms are often used to mean the rock and soil.

Serpentine soils are ubiquitous but with patchy distributions and have three traits; poor plant productivity, high rates of endemism, and vegetation types distinct from neighboring areas. The soils derived from ultramafic bedrock give rise to unusual and sparse associations of edaphic (and often endemic) plants that are tolerant of extreme soil conditions, including:

Physically these areas are characteristically steep, rocky, and vulnerable to erosion, which results in shallow soils. The shallow soils and sparse vegetation lead to elevated soil temperatures and dry conditions.

Serpentine is a unique classification of soils as they are relatively rare, and exhibit distinct chemical properties. The soil in appearance is often reddish, brown, or gray in color. The parent material for serpentine soil is mostly derived from the rock serpentine, noted for its waxy greenish-silver to bluish-silver appearance. The rock has white streaks of mineral running through it that contain naturally occurring asbestos. Asbestos is composed of microscopic needle-like crystals made from magnesium-Iron silicate. Asbestos is linked to an array of human health conditions such as mesothelioma from long time exposure of breathing in the dust particles. Caution should be taken when working in serpentine soils or when working with crushed serpentine rock.

Serpentine-rich rock or serpentinite has a mottled, greenish-gray color with a waxy feel to it. These rocks form by the reaction of olivine-rich rock, peridotite, with water.

It forms in oceanic crust near the surface of the earth, particularly where water circulates in cooling rock near mid-ocean ridges: masses of the resulting ultramafic rock are found in ophiolites incorporated in continental crust near present and past plate tectonic boundaries.

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