Ch 3 earth science PPT

The Rock Cycle


Ag Earth Science – Chapter 3.1

3.1 Vocabulary


mineral



A natural occurring, inorganic crystalline
material with a unique chemical
composition.


rock



A consolidated mixture of minerals


igneous rock



A rock formed by the crystallization of
molten magma

sedimentary rock



Rock formed by from weathered products
of preexisting rocks that have been
transported, deposited, compacted, and
cemented.


metamorphic rock

Rock formed by the alteration of preexisting rock
deep within the Earth by heat, pressure, and/or
chemically active fluids.


rock cycle

A model that illustrates the origin of the three
basic rock types and the interrelatedness of Earth
materials and processes.


magma

A body of molten rock found at depth including
any dissolved gases and crystals.

lava

Magma that reaches the Earth’s surface.


weathering

The disintegration and decomposition of rock at
or near the Earth’s surface.


sediments

Loose particles created by weathering and
erosion of rock, by chemical precipitation from
solution in water, or from the secretions of
organisms and transported by water, wind, or
glaciers.


Rocks



A rock is any solid mass of mineral or
mineral-like matter that occurs naturally as
part of our planet.



Rocks are classified into 3 major types

 Igneous Rocks
 Sedimentary Rocks
 Metamorphic Rocks




Interactions among the Earth’s water, air, and
land can cause rocks to change from one type to
another



The continuous processes that cause rocks to
change make up the rock cycle

 When magma (molten material beneath
the Earth’s surface) cools and hardens,
igneous rocks form. Magma that reaches
the surface is called lava.

The Rock Cycle


 When weathered (process by which rocks
are physically and chemically broken
down into small pieces called sediments)

sediments are compacted and cemented
together, they form sedimentary rocks.

 When sedimentary rocks are subjected to
extreme pressure and heat, they change in
metamorphic rock.


The Rock Cycle


Powers of the Earth’s Rock Cycle



Heat from the Earth’s interior are
responsible for forming both igneous and
metamorphic rocks



Weathering and the movement of
weathered materials are generated by the
sun’s energy and produce sedimentary
rock.


Ag Earth Science – Chapter 3.2

3.2 Vocabulary

ignis



Latin word for “fire”


intrusive igneous rock



Igneous rock that formed below the Earth’s
surface


extrusive igneous rock



Igneous rock that has formed on the
Earth’s surface


porphyritic texture



An igneous texture consisting of large

crystals embedded in a matrix of much
smaller crystals


granitic composition



A compositional group of igneous rocks
that indicate a rock is composed entirely of
light-colored silicates, mainly quartz and
feldspar


basaltic composition



A compositional group of igneous rocks
indicating that the rock contains
substantial dark silicate minerals and
calcium-rich plagioclase feldspar


andesitic composition



A composition of igneous rocks lying
between felsic and mafic