Where can you find eclogite facies?
Transitional granulite-eclogite facies granitoid, felsic volcanics, mafic rocks and granulites occur in the Musgrave Block of the Petermann Orogeny, central Australia. Coesite- and glaucophane-bearing eclogites have been found in the northwestern Himalaya.
Where is eclogite formed?
Laboratory experiments have revealed that eclogites will crystallize from basaltic magma under very high pressure conditions common to the deeper portions of the Earth’s upper mantle, the mantle constituting the layer that lies between the crust and core and that comprises about two-thirds of the planet’s bulk.
What grade is eclogite facies?
Amphibolite facies: medium-grade metamorphism. Granulite facies: high-grade metamorphism. Blueschist facies: low-temperature/high-pressure metamorphism. Eclogite facies: high-grade metamorphism.
What is the importance of eclogite?
Eclogites are helpful in elucidating patterns and processes of plate tectonics because many represent oceanic crust that has been subducted to depths in excess of 35 km and then returned to the surface.
What type of metamorphic rock is eclogite?
Eclogite is a metamorphic rock consisting of pyroxene omphacite and pyrope-rich garnet. It is a rare but geologically significant rock type. It is common in the upper mantle, especially in regions occupied by subducted oceanic plates.
What are the characteristics of eclogite facies?
Eclogite facies is characterized by pressures in excess of 1.2 GPa (45 km depth) and temperature exceeding at least 400-500 °C. 400-500 degrees at 45 km depth is below the crustal average (25 °C per kilometer of depth).
What is the composition of eclogite?
The eclogite facies was initially recognized in rocks only of basaltic composition, which are transformed at the pressure-temperature conditions of the eclogite facies into spectacular red and green rocks composed of the anhydrous mineral assemblage garnet plus omphacite.
What is the width of view of eclogite?
Width of view is about 15 cm. It is chiefly composed of red (garnet) and green (omphacite) minerals. Garnet in eclogite is usually iron-rich pyrope (contains similar amount of Mg and Fe). Omphacite is a pyroxene group mineral with a composition in the middle between jadeite and diopside.
Where can you find eclogite in the US?
Eclogite from Almenning, Norway. The red-brown mineral is garnet, green omphacite and white quartz. Occurrences exist in western North America, including the southwest and the Franciscan Formation of the California Coast Ranges.