What is the protolith of eclogite?
Eclogite contains no plagioclase although its protolith is full of this mineral. The protoliths of eclogites are igneous rocks with a basaltic composition (basalt, diabase, gabbro). The lack of relatively light-weight plagioclase is the reason why it is so dense compared to its protoliths.
What is the density of eclogite?
3.45 to 3.75 g/cm3
The STP densities of peridotites vary from 3.3 to 3.47 g/cm3; eclogite densities range from 3.45 to 3.75 g/cm3.
What is the grain size of eclogite?
Phengite and ilmenite are rarely present. Omphacite occurs as aligned elongated crystals that impart a strong compositional layering and a penetrative lineation to the eclogite. Garnets occur as small subidioblastic grains, usually 0.3 mm in size; larger grains (up to ∼0.6 mm) are rare.
What is the protolith for calcareous rocks?
Pelitic protoliths are mainly composed of clay minerals derived from weathered and eroded continental crust. Low-grade metamorphic marls are calcareous micaschists, whereas the formation of Ca-rich silicate minerals during higher-grade metamorphism results in calcsilicate rocks.
Which is the protolith of an eclogite rock?
The protoliths of eclogites are igneous rocks with a basaltic composition (basalt, diabase, gabbro ). The lack of relatively light-weight plagioclase is the reason why it is so dense compared to its protoliths. The formation of eclogite may be expressed by the following chemical equation:
What kind of density does eclogite rock have?
Eclogite is unusually dense for a silicate rock (3.4–3.5 g/cm 3) which suggests that very high pressure was involved in the formation of this rock type. Eclogite is a very beautiful rock.
Is it possible to melt eclogite to produce basalt?
Melting of eclogite to produce basalt directly is generally not supported in modern petrology. Unreasonably high degrees of partial melting are required to attain basaltic compositions.
Why is there no plagioclase in an eclogite?
Eclogite contains no plagioclase although its protolith is full of this mineral. The protoliths of eclogites are igneous rocks with a basaltic composition (basalt, diabase, gabbro). The lack of relatively light-weight plagioclase is the reason why it is so dense compared to its protoliths.
