Download sedimentary rocks

IGNEOUS ROCKS (FROM MAGMA SOLIDIFICATION)
Intrusive (plutonic)
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Extrusive (volcanic)
slow cooling of magma
mineral size: medium and large size
fast cooling
tiny size or no minerals (glass forms)
or large minerals in amorphous matrix
(porphiric texture)
CHEMICAL COMPOSITION (% SiO2, silica)
FELSIC
>65%
INTERMEDIATE
55-65%
MAFIC
45-55%
GRANITE (I)
ANDESITE(e)
BASALT(E)
RHYOLITE(e)
DIORITE(I)
GABBRO(i)
LIGHT COLORED
INTERM. COLORED
ULTRAMAFIC
DARK COLORED
<45%
PERIDOTITE (I)
DARK/GREEN
SEDIMENTARY ROCKS
Sedimentary rocks are formed from pre-existing
rocks or pieces of once-living organisms. They form
from deposits that accumulate on the Earth's surface.
Origin of sediments
CLASTIC
CHEMICAL
from pieces of
formed by chemical precipitation
pre-existing rocks
from clay
from sand
LIMESTONE
SHALE
CHERT
SANDSTONE
BIOLOGIC
TRAVERTINE
from pebbles and cobbles
from deposit of
CONGLOMERATE
animal shells
Ca carbonate
Ca, Mg carbonate
LIMESTONE
DOLOSTONE
METAMORPHIC ROCKS
Metamorphic rocks are rocks that have been changed from their original igneous,
sedimentary, or metamorphic form. Metamorphic rocks form when rocks are subjected to
high heat and/or high pressure.
FOLIATED
NON FOLIATED
PRESSURE
squeezes the flat or elongate
minerals within a rock so they become
aligned.
Contact metamorphism: preexisting rocks are baked by the
HEAT
rocks cleavage: rock splits along a plane
created by parallel grains
SCIST
GNEISS (HEAT+PRESSURE)
no cleavage
MARBLE (from LIMESTONE)
QUARTZITE(from SANDSTONE)
SLATE (from SHALE)