What is a peridotite in geology ?
Peridotite : definition
A peridotite is a granular ultrabasic plutonic rock, dark in color, made up of more than 90% ferromagnesian minerals : dominant olivine, accompanied by pyroxene and spinel (picotite, chromite), sometimes amphibole, garnet (especially pyrope), and biotite. According to the mineralogical composition, we distinguish : dunites (more than 90% olivine), and among peridotites containing between 40% and 90% olivine : wehrlites (with clinopyroxene), harzburgites (with orthopyroxene) and lherzolite (with clinopyroxene and orthopyroxene.
Peridotites form the basis of ophiolitic complexes and stratified lopolites, as well as most of the upper mantle, making them probably the most abundant rock on earth.
Some volcanic rocks, such as komatiites andkimberlites (olivine, phlogopite and serpentine), have a peridotitic affinity.
Peridotites form the basis of ophiolitic complexes and stratified lopolites, as well as most of the upper mantle, making them probably the most abundant rock on earth.
Some volcanic rocks, such as komatiites andkimberlites (olivine, phlogopite and serpentine), have a peridotitic affinity.