What minerals make up serpentinite?
What minerals make up serpentinite?
Serpentine rock is primarily composed of one or more of the three magnesium silicate minerals, “lizardite,” “chrysotile,” and “antigorite.” Chrysotile often occurs as fibrous veinlets in serpentine.
How is serpentinite formed?
The serpentinite is formed by the hydrous alteration and low-temperature metamorphic alteration of igneous ultramafic rocks. These rocks are composed of olivine and pyroxene in different ratios to form peridotite and pyroxenite.
What is the process of Serpentinization?
Serpentinization is a processes whereby rock (usually ultramafic) is changed, with the addition of water into the crystal structure of the minerals found within the rock. A common example is the serpentinization of peridotite (or dunite) into serpentinite (the metamorphic equivalent).
What type of metamorphism is serpentinite?
Serpentinite is a metamorphic rock that is mostly composed of serpentine group minerals. Serpentine group minerals antigorite, lizardite, and chrysotile are produced by the hydrous alteration of ultramafic rocks. Brucite forms if the precursor rocks are rich in magnesium (dunite, for example).
Is serpentinite regional metamorphism?
Contact metamorphic rocks are found in contact with igneous intrusions (or near such a contact), hence the name….
| Foliated Metamorphic Rocks | Crystal Size | medium to coarse |
|---|---|---|
| Mineralogy | serpentine, magnetite, talc, chlorite | |
| Parent Rock | peridotite, dunite | |
| Metamorphism | low grade regional | |
| Rock Name | serpentinite |
What is Coolac serpentinite belt?
The Coolac Serpentinite Belt extends over 130 km from Young in the north to Tumut in the south and hosts a number of chromite deposits/occurrences. The prominent deposits are Wallendbeen, Gundagai, and Tumut. The host rock represents a deformed and disrupted oceanic crust of the Late Silurian to Early Middle Devonian.
Is there talc in serpentinite?
Mafic lithologies within serpentinite are rodingitized in many instances, and in the shear zones the foliated serpentinite adjacent to mafic blocks may also include tremolite. Talc has not been found, though it may have been replaced during the 90 Myr exhumation history of the LFC.
Where does serpentine come from?
Serpentine has been mined from several Alpine-type serpentinite deposits in eastern New South Wales, including the Somerset Mine in the Coolac Serpentine Belt (Figure 24) (Ambler 1984); and the Ironbark Creek serpentine quarry, Attunga magnesite quarry and Tundi deposits in the Great Serpentinite Belt of the New England Orogen.
What is the great serpentinite belt?
The Great Serpentinite Belt extends ∼120 km hosting four major deposits from north to south: Bingara, Barraba, Attunga, and Nundle. The chromite pods developed along the Peel Thrust and extend southeasterly from Bingara, through Barraba, to Bowling Alley Point near Nundle.
