Sea Floor Metamorphism

Ocean floor metamorphism is a concept that has arisen from recent studies of present oceanic ridges and fracture zones where new crust is being generated altered and deformed.

Sea floor metamorphism. It is suggested that metamorphism took place in a sub sea floor geothermal system and that such systems are an integral part of the sea floor spreading process. Within the metamorphic facies the term mineral assemblage is used when some of the secondary minerals formed suggest a metamorphic paragenesis. Of the samples of ocean crust recovered from the ocean floor by drillling or dredging are altered.

While rocks can be metamorphosed at depth in most areas the potential for metamorphism is greatest in the roots of mountain ranges where there is a strong likelihood for burial of relatively young sedimentary rock to great depths as depicted in figure 7 15. Many good examples of seafloor metamorphism are known from ophiolites in the sierra nevada and klamaths. Recognition of on land ophiolite suites as ancient examples of oceanic crust and mantle provide insights into the thermal and dynamothermal regimes that characterize ocean floors.

Of metamorphism in the mountain belt during orogensis or resulted from the latter is now the favoured explanation. 1 the zeolite facies 2 the prehnite pumpellyite facies 3 the greenschist facies and 4 the amphibolite facies. The ocean floor metamorphics are classified in four major categories.

Most regional metamorphism takes place within continental crust. Hydrothermal circulation produces low p t metamorphism often called seafloor metamorphism. Metamorphism caused by high pressures and temperatures that extend over larger regions as happens where plates collide.

Seafloor metamorphism metamorphism associated with mid ocean ridges in which changes in a rock s bulk chemical composition are produced by fluid transport of chemical components into or out of the rock.