What is the parent rock of serpentinite?
The name Serpentinite comes from the similarity of the rock's texture to the skin of a snake.Minerals in this group, which are rich in magnesium and water, light to dark green, greasy looking and slippery feeling, are formed by serpentinization, a hydration and metamorphic transformation of ultramafic rock from the Earth's mantle.At the sea floor, the mineral alteration is important.[3]
The oxidation of low-silica mafic and ultramafic rocks by the protons of water leads to the formation of H2 in serpentinite.Some rare minerals, such as awaruite (Ni3Fe), and even native iron, can be found at and near the seafloor and in mountain belts.In the process large amounts of water are absorbed into the rock increasing the volume and decreasing the density.[4]
The density goes from 3.3 to 2.7 g/ cm3 with a concurrent volume increase of 30-40%.The energy source for the formation of non-volcanic hydrothermal vents can be found in the rock temperatures raised by the reaction.The hydrogen gas produced by the chemical reactions is far from the Earth's atmosphere.Methane and hydrogen sulfide are formed when carbonates and sulfates are reduced.The hydrogen, methane, and hydrogen sulfide are found in the deep sea.[4]
Serpentinite can be formed from a number of reactions.The solution of forsterite, magnesium-endmember, and fayalite is called olivine.
The hydration of olivine is described in Reaction 1c.In the presence of brucite like calcium silicate hydrate, (C-S-H) phases formed along with portlandite (Ca(OH)2) in hardened Portland cement paste after the hydration of belite, Serpentine is stable at high pH.
The poorly soluble reaction products can be moved out of the serpentinized zone.
A similar suite of reactions involves pyroxene-group minerals, though less readily and with a different set of end-products.The magnesian chlorite can be used together with the antigorite, lizardite, and chrysotile.Rock composition, temperature, and pressure are some of the factors that affect the final mineralogy.During metamorphism, antigorite forms in reactions at temperatures that can exceed 600 C (1,112 ) and it is the group serpentine mineral stable at the highest temperatures.At low temperatures near the Earth's surface, lizardite and chrysotile can form.Metasomatic reaction zones enriched in calcium and called rodingites can be created by fluid reaction with rocks that are involved in serpentinite formation.
In the presence of carbon dioxide, serpentinitization can form either magnesite or methane.Some gas may be produced by serpentinite reactions.
Reaction 2a is favored if the serpentinite is poor or if there isn't enough carbon dioxide.In highly magnesian compositions and low partial pressure of carbon dioxide, Reaction 2b is favored.
The degree to which a mass of ultramafic rock undergoes serpentinisation depends on a number of factors.If an olivine composition contains enough fayalite, it can transform into a closed system.In most ultramafic rocks formed in the Earth's mantle, the olivine is only about 10% forsterite endmember, so magnesium must be transported out of the reacting volume.
Serpentinitization of a mass of peridotite usually destroys previous evidence because the minerals are weak and behave in a very ductile fashion.Some of the serpentinite may have behaved in a rigid fashion, as evidenced by the preservation of texture from the peridotite.
There is a reaction between water and fayalite'sFe2+ ion.The process produces hydrogen gas.
The Schikorr reaction was observed in the oxidation of the ferrous hydroxide in contact with water.
There is a theory that traces of methane in the atmosphere of Mars could be evidence for life.Serpentinization is an alternative non-biological source for methane traces.It was 9 and 10.
Scientists were able to confirm that Enceladus has a liquid water ocean using data from the Cassini probe.A model suggests that the ocean on Enceladus has an alkaline pH.The high pH is thought to be a consequence of serpentinization of chondritic rock that leads to the generation of H2, a source of energy that can support both abiotic and biological synthesis of organic molecule.[11][12]
There is thin or absent soil cover over serpentinite bedrock.The soil with serpentine is rich in elements that are toxic to plants.It was [13].
The verd antique form of serpentinite has historically been used as decorative stones for their marble-like qualities.College Hall at the University of Pennsylvania is made of serpentine.The mountains of Italy and Greece were popular before contact with the Americas.Serpentinites are used in many different ways.The rock has been turned in Zblitz for hundreds of years.[15]
The carved bowl shaped serpentinite Qulliq or Kudlik lamp was used by the Inuit and indigenous people of the north to make light and cook with oil or fat.Inuit made tools and carvings of animals.