Chapter 8 test 2 Flashcards
Metamorphism
the transition of one rock into another by temperature and/or pressure.
contact or thermal metamorphism
rocks that change by a rise in temperature within the hose rock
hydro thermal metamorphism
chemical alterations from hot, ion rich water
regional metamorphism
produces the greatest volume of metamorphic rock.
rocks usually display zones of contact and/or hydro thermal metamorphism
occurs during mountain building.
texture
refers to the size, shape, and arrangement of grains within a rock.
foliation
any planar arrangement of mineral grains or structural feature within a rock
parallel alignment of flattened mineral grains and pebbles
compression
flat arrangement of mineral grains.
slaty cleavage
where rocks can be easily split into thin tabular sheets
foliated textures
rock or slaty cleavage
schistosity
gneissic
nonfoliated
marble
quartzite
Slate
very fine grained
excellent rock cleavage
most often generated from low grade metamorphism of shale, mudstone, or siltstone
schist
medium coarse grained
platy minerals predominate
commonly include the micas
parent rock is shale
Gneiss
medium coarse grained
branded apperance
high grade metamorphism
metamorphism of granite
Marble
coarse crystalline
parent rock is limestone or dolostone
used as decorative and monument stone
quartzite
formed from quartz rich sandstone. quartz grains are fused together.
contact or thermal metamorphism
occurs due to a rise in temperature when magma invades a host rock.
a zone of alteration called an aureole forms in the rock surrounding the magma.
hydro thermal metamorphism
chemical alteration caused when hot ion rich fluids called hydro thermal solutions circulate through fissures and cracks that develop in the rock.
mid ocean ridge.
regional metamorphism
produces the greatest quantity of metamorphic rock
associated with mountain building and subduction.
burial metamorphism
associated with very thick sedimentary strata
required depth varies from one location to another depending on the prevailing geothermal gradient.
metamorphism along fault zones
occurs at depth and high temps
pre existing minerals elongate so the rock becomes foliated
impact metamorphism
occurs when high speed projectiles called meteorites strike the earths surface
products are called impactites.
