Geology Chapter 7 Summary

Metamorphoic rocks are subjected to = high temp and high confining pressure.

Foliation in metamorphic rocks due to = differential stress

differential stress = pressure different on surfaces

confining pressure = pressure applied equally on surfaces

Types of foliation = Slaty, Schistase, Gneissic

Slaty = splits easily along nearly flat and parallel planes

Schistose = platy, needle shaped parallel to plane due to differential stress.

Schist, slate, phyllite, and gneiss are what rocks? foliated rocks that indicate increasing grade of regional metamorphism

Contact metamorphic rocks = produced without significant differential stress but with high temperature

Contact metamorphism occurs in rocks? immediately adjacent to intruded magmas

Contact metamorphism produces = non foliated rocks (marble, quartzite)

Regional metamorphism involves = heat, confining pressure, differential stress

Hydrothermal veins = form when hot water precipitates material that crystallizes into minerals.

Regional metamorphism produces = foliated rocks

Plate tectonic theory explains = 1)the deep burial of rocks originally formed near surface 2) intense squeezing necessary for differential stress (foliated rocks) 3) presence of water deep within lithosphere 4)wide variety of pressures and temperatures present during metamorphism

Marble are from = calcite (nonfoliated)