Coal Explained

rock

During subduction, a tectonic plate, consisting of oceanic crust and lithospheric mantle, is recycled back into the deeper mantle. In most subduction zones the subducting plate is relatively chilly compared with the excessive temperature it had when first fashioned at a mid-ocean spreading ridge. Subduction takes the rocks to nice depth within the Earth comparatively rapidly. This produces a characteristic kind of metamorphism, typically known as excessive-pressure, low-temperature (excessive-P, low-T) metamorphism, which solely happens deep in a subduction zone.

(Foliated means the parallel arrangement of sure mineral grains that gives the rock a striped appearance.) Foliation forms when stress squeezes the flat or elongate minerals within a rock so they turn into aligned. These rocks develop a platy or sheet-like structure that reflects the direction that pressure was utilized. Metamorphic rocks started out as some other type of rock, but have been substantially changed from their originaligneous,sedimentary, or earlier metamorphic … Read More