Definition of blueschist
plural blueschists
geology
: a metamorphic rock that is formed under high pressure and low temperature and is characterized by the presence of glaucophane
- Also radiometric ages of blueschists from the same regions cluster around 400-500 Myr.
- —T. Nakajima et al., Nature, 19 July 1990
- At this depth, where the pressure is 15 to 20 kilobars and temperatures reach about 500 degrees C, rocks called blueschists and eclogites form.
- —Ian Anderson, New Scientist, 29 Mar. 1997
