chapter 14 building the crust with rocks Flashcards
our success as a species is directly linked to
earths rocks
about ____ years ago early hominids began chipping and grinding rocks into tools
2.6 million
mineral
a naturally occurring, crystalline, solid chemical element or compound with a uniform chemical composition, minerals are abiogenic - not made by organisms
rock
a solid mass composed of one or more types of minerals
crystallization
the process in which atoms or molecules come together in an orderly patterned structure
four mineral classes
silicates
oxides
sulfides
sulfates
silicate minerals are formed by the combination of ____ and ____
silicon and oxygen
halides
basically different types of salts that are relatively soft
oxides
gives many rocks a reddish color (rust)
sulfides
makes pyrite which is also known as fools gold
carbonates
often bonds sand grains together
sediments
accumulations of small fragments of rock and organic material that are not cemented together
outcrops
exposed areas of bedrock
igneous rocks
form when magma or lava solidifies
sedimentary rock
form through cementation and compaction of sediments
metamorphic rock
form by heat and pressure applied to preexisting rocks
rock cycle(definition)
model of the processes by which rocks form, are transformed from one type to another and are recycled into the mantle
lithification
the transformation into rock
decompression vs flux melting
decompression- melting of hot mantle material into magma as a result of pressure changes
flux- subducted water causes mantle material to melt by lowering its melting point
extrusive vs intrusive igneous rock
extrusive- rock that cooled from lava on crusts surface
intrusive- rock that cooled from magma deep underground
batholith
body of intrusive igneous rock hundreds of kilometers in extent
pluton
igneous rock mass no more than a few tens of kilometers in diameter
sill
flat sheet of igneous rock that has cooled from magma from layers of preexisting rock
dike
vertical sheet of igneous rock
laccolith
shallow dome shaped igneous rock body
types of igneous rock
phaneritic- coarse grained rocks with large crystals that formed slowly deep in the crust
aphanitic- rocks that cool more quickly closer to the surface
glassy- no orderly crystalline arrangement of atoms because they cool at the surface
sedimentary rock groups
clastic- composed of broken pieces of other rocks
organic- composed of organic material derived from ancient organisms or their shells
chemical- formed as dissolved minerals precipitate out and as water evaporates from sedimentary deposits
shale
a clastic sedimentary rock formed from clay sized particles
sandstone
a clastic sedimentary rock composed chiefly of quartz sand grains
limestone
either a chemical sedimentary rock or an organic sedimentary
coal
organic sedimentary rock formed from peat
peat
heavy soil found in wetlands made up of the partially decomposed remains of plants
evaporite
a deposit of one or more minerals resulting from the repeated evaporation of water from a basin
fossils
the remains or impressions of organisms preserved in sedimentary rock
protolith
the og rock
contact vs regional metamorphism
contact- occurs when rock comes into contact with and is heated by magma
regional- where the crust is being compressed, such as in a collision zone between two convergent continental plates
fracking
the procedure in which water, sand, and chemicals are pumped under high pressure into shale bedrock to extract natural gas and petroleum trapped in the pores of the shale
