http://www.learner.org/interactives/rockcycle/
Catherine M.
A group of processes through
which Earth materials may pass
as they are transformed from one
major rock type to another.
Three Major Rock Types
• Uplift and Magma dispersement
• Weathering and Erosion
• Deposition of material
• Sedimentary Rock is created
• Heat + Pressure + Time = Metamorphic Rock
• More Heat + Pressure = Igneous Rock
http://www.windows.ucar.edu/tour/link=/earth/geology/rock_cycle.html
Sedimentary rock is formed when sediment
comes together and bonds either by
compaction, cementation or both.
There are three types of sedimentary rocks:
Quartz Sandstone
Clastic – formed by mechanical weathering
debris
Chemical – formed by dissolved materials in a
solution
Organic – accumulation of plant or animal
debris Shelf Shale (Clay)
Each type of sedimentary rock has its own
distinct composition, color and texture.
Sedimentary rock is the only place where we
find fossils.
Limestone (crushed shell)
http://csmres.jmu.edu/geollab/fichter/SedRx/SimpModl.html
Breccia - Clastic Coal - Organic Iron Ore - Chemical
Conglomerate - Clastic Sandstone - Castic Rock Salt - Chemical
http://geology.com/rocks/sedimentary-rocks.shtml
Metamorphic rock is any rock that has
been changed from its original
condition by heat, pressure and the
chemical activity of fluids, as in marble
and slate.
This change usually occurs under the
Earth’s surface and when conditions are
right, heat and pressure cause the mineral
composition and/or texture to transform the
original rock into a newly formed rock.
http://www.windows.ucar.edu/tour/link=/earth/geology/meta_intro.html
• Rocks that are in contact with hot magma
or lava often become metamorphosed.
This is called contact metamorphism.
• Contact metamorphism can either happen
deep underground or at the Earth's
surface. Underground, hot magma, fills
areas within the crust; large areas are
called batholiths. The hot magma alters
the surrounding rocks. The amount of
rock that is changed depends on how
much magma there is producing heat.
http://www.windows.ucar.edu/tour/link=/earth/geology/meta_contact.html
• Above ground, lava erupting from a
volcano alters the rock that it erupts onto.
• Sometimes rocks are metamorphosed over
large areas that are the size of many states
or even several countries. This is called
regional metamorphism.
• Pieces of the Earth's surface layer (called
the lithosphere) crash into each other,
rocks are squished and changed deep
within mountain ranges. This type of
process happens along convergent
boundaries.
• One piece of the lithosphere is pulled below
another and the rocks are altered deep
underground by the high pressure and
temperature. This type of process is
referred to as Subduction.
http://www.windows.ucar.edu/tour/link=/earth/geology/meta_regional.html
Slate
Gneiss
Marble
Hornfels Garnet Schist Quartzite Schist (Muscovite)
• Igneous rocks are divided
into two groups, based on
where the rock forms.
• Intrusive igneous rocks are
formed inside the Earth and
extrusive igneous rock are
formed when they cool on
the surface.
http://volcano.und.edu/vwintl/vwintl.html
Soufriere Hills, Montserrat
• Many kilometers below the Earth’s
surface, molten rock called magma
flows into cracks or underground
chambers. There, the magma sits,
cooling very slowly over thousands to
millions of years. As it cools, elements
combine to form common silicate
minerals, the building blocks of
igneous rocks. These mineral crystals
can grow quite large if space allows
and can be seen with the naked eye.
http://www.windows.ucar.edu/tour/link=/earth/geology/ig_intrusive.html
• There are many different types of
intrusive igneous rocks but granite is
the most common type.
Granite
Gabbro
Pegmatite
http://www.beg.utexas.edu/mainweb/publications/graphics/granite-400.jpg http://geology.com/rocks/igneous-rocks.shtml (2)
The molten rock (magma) erupts or flows
above the surface as lava, and then cools
forming rock.
When lava erupts onto the Earth's surface, it
cools quickly. If the lava cools in less than a
day or two, there is no time for elements to
form minerals. Instead, elements are frozen
in place within volcanic glass. Often, lava
cools over a few days to weeks and minerals
have enough time to form but not time to
grow into large crystals.
Basalt is the most common type of extrusive
igneous rock and the most common rock
type at the Earth's surface.
Stromboli, Italy
http://www.windows.ucar.edu/tour/link=/earth/geology/ig_extrusive.html
Basalt Obsidian
Scoria
Pumice Welded Tuff
http://geology.com/rocks/igneous-rocks.shtml
http://www.msnucleus.org/membership/html/k-6/rc/rocks/6/rcr6_2a.html