Lesson 6: Types of Rocks and their Properties Flashcards
Earth is a solid rock to a depth of
2,900 kilometers
a naturally occurring solid aggregate of one or more minerals.
rock
The
aggregate minerals forming the rocks are held together by
chemical bonds
the scientific study of rocks
petrology
how are rocks classified
based on how they were formed
three types of rocks
igneous, sedimentary, and metamorphic rock
formed from hardening and crystallization of magma or molten material that
originates deep within the earth.
Igneous
two types of igneous rock
extrusive/volcanic and intrusive/plutonic
forms when magma makes its way to Earth’s surface
as lava and then cools.
extrusive/volcanic
the crystals of extrusive/volcanic rocks are:
very small (fine grained) since the cooling process is fast
It cools slowly beneath the Earth surface and are created by magma.
intrusive/plutonic rock
the crystals of intrusive/plutonic rocks are:
very large (coarse grained)
igneous rocks are classified based on
composition and texture
four types of igneous rock composition
FELSIC, MAFIC, INTERMEDIATE, and ULTRAMAFIC
light in color; feldspar and silicates
FELSIC
dark in color; made up of magnesium and iron
MAFIC
between mafic and felsic
INTERMEDIATE
very dark color
ULTRAMAFIC
overall appearance of rock
texture
fine grained
aphanistic
coarse grained
phaneritic
large crystals with small crystals
porphyritic
non-ordered solid from rapid quenching
glassy
composite of ejected fragments
pyroclastic
provide information about surface conditions that existed in the
Earth’s past.
sedimentary rocks
Particles of sand, shells, pebbles, and other fragments of materials called
sediments
due to increase of pressure of layered sediments it bind together to form
sedimentary rocks
three types of sedimentary rocks
clastic, chemical, and organic
formed from accumulation of clasts: little pieces of broken
rocks and shells.
clastic sedimentary rock
formed when dissolved minerals precipitate from a solution
chemical sedimentary rock
rocks formed from the accumulation of animal debris
organic sedimentary rocks
formed when a body of seawater becomes closed off and evaporates.
halite
composed of organic matter in the form of plants fragments.
coal
forms from pre-existing rocks: either metamorphic, igneous,
sedimentary
metamorphic rocks
transformation of one rock type into another.
metamorphism
two types of metamorphism
regional and contact
mainly by heat due to contact with magma
contact
due to changes in pressure and temperature over large region of the crust
regional
two classifications of metamorphism
texture and foliation
refers to the size arrangement and grains within the rock
texture
any planar arrangement of mineral grains or structural features within the rock
foliation
appeared banded or layered, contains crystals
foliated
made up of only a few minerals
non-foliated
are formed from melted rock deep inside the Earth.
igneous rocks
are formed from layers of sand, silt, dead plants, and animal skeletons.
sedimentary rocks
formed from other rocks that are changed by heat and pressure underground.
metamorphic rocks
four steps in the formation of sedimentary rocks
weathering, erosion, deposition, compaction, and cementation
particles are carried away by wind or water
erosion
loosely packed sediments
deposition
closely packed sediments
compaction
tightly packed sediments
cementation
rock cycle
magma > intrusion or eruption > igneous > weathering,erosion, transport, deposition > sedimentary > heat and/or pressure > metamorphic > burial and extreme heat
what parts of the rock cycle are connected
- igneous > magma
- igneous > metamorphic
- metamorphic > sedimentary