Epidosite
Encyclopedia
Epidosite is a highly altered epidote
and quartz
bearing rock. It is the result of slow hydrothermal fluid alteration of basalt
that occurs below the black smokers within mid-oceanic ridge spreading centers. Similar altered rocks have been identified within ophiolite
complexes and associated sulfide
ore
deposits. Epidosites represent the zone of intense metal leaching below and lateral to the black smoker environment which is the result of convection of ocean water through the fractured basalts of the ridge flanks.
Epidote
Epidote is a calcium aluminium iron sorosilicate mineral, Ca2Al2O, crystallizing in the monoclinic system. Well-developed crystals are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often...
and quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
bearing rock. It is the result of slow hydrothermal fluid alteration of basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
that occurs below the black smokers within mid-oceanic ridge spreading centers. Similar altered rocks have been identified within ophiolite
Ophiolites
An ophiolite is a section of the Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed above sea level and often emplaced onto continental crustal rocks...
complexes and associated sulfide
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...
ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
deposits. Epidosites represent the zone of intense metal leaching below and lateral to the black smoker environment which is the result of convection of ocean water through the fractured basalts of the ridge flanks.