eclogitt

Eclogitt is not a recognized term in standard geology. It is likely a misspelling or informal variant of eclogite, a well-established high-pressure metamorphic rock. This article uses eclogite as the closest established concept to describe what eclogitt may refer to.

Eclogite is a metamorphic rock that forms under high pressure in subduction zones. Its characteristic mineral assemblage is garnet (often almandine or pyrope-rich varieties) and omphacite, a sodium-rich clinopyroxene. The rock is usually dense, coarse-grained, and may display interlocking textures between garnet and omphacite. Accessory minerals such as rutile, amphibole, quartz, or phengite may occur.

Formation and conditions occur deep within the Earth's crust where basaltic or gabbroic protoliths are subjected to pressures typically greater than about 1.0–1.5 gigapascals and elevated temperatures. This eclogite facies metamorphism is commonly associated with subduction zone processes, where crustal rocks are carried to great depths and later exhumed.

Geographic distribution includes numerous continents and mountain belts where ancient subduction and collision have preserved high-pressure rocks. Eclogites provide important records of crustal recycling and subduction zone dynamics, helping to constrain pressure–temperature histories and the evolution of Earth's tectonics.

Eclogite-bearing terranes are often used to interpret the depth and rate of subduction, the age of metamorphism, and the thermal structure of subduction zones. They are contrasted with other high-pressure rocks such as blueschist and granulite, which form under different P–T conditions.

See also: eclogite facies, subduction zone metamorphism, garnet, omphacite.