Name___________________________________ J#______
Interactive Rock Cycle
1.
Go to http://www.learner.org/interactives/rockcycle/ *First check to make sure your computer will
print!
2. Take notes based on the clues I have provided you:
The three main types, or classes, of rock are sedimentary, metamorphic, and igneous and the differences
among them have to do with how they are formed.
Sedimentary
How are sedimentary rocks formed?
Sedimentary rocks are formed from particles of sand, shells, pebbles, and other fragments of material.
 Sediment accumulates in layers
 Over a long period of time hardens into rock
 Can be fairly soft and may break apart or crumble easily
 Can often see sediment pieces in the rock
 Usually the only type that contains fossils
What is sediment?
Particles of sand, shells, pebbles, and other fragments of material= Products of Erosion and Weathering.
Give two examples:
Limestone, Shale, Sandstone, Conglomerate
Metamorphic
How are metamorphic rocks formed?
Metamorphic rocks are formed under the surface of the earth from the metamorphosis (change) that
occurs due to intense heat and pressure (squeezing).
Describe them:
 Often have ribbonlike layers
 Can have shiny crystals formed by minerals growing slowly over time, on their surface (not
throughout the rock).
Give two Examples:
Gneiss, Quartzite, and Marble
Igneous
How are igneous rocks formed?
Igneous rocks are formed when magma (molten rock deep within the earth) cools and hardens.
Describe the TWO ways igneous rocks form:


Magma cools inside the earth—Intrusive Igneous
Magma erupts onto the surface from volcanoes (in this case, it is called lava)—Extrusive
* When lava cools very quickly, no crystals form and the rock looks shiny and glasslike (obsidian).
Sometimes gas bubbles are trapped in the rock during the cooling process, leaving tiny holes and
spaces in the rock (basalt).
Give two examples:
Basalt, Granite and Obsidian
Complete the chart below: This chart shows the characteristics that help scientists to identify rocks within the
three classes.
Crystals
Small, flat
surfaces that are
shiny or sparkly,
like tiny
mirrors.
Marble
Fossils
Imprints of
leaves, shells,
insects, or other
items in the
rock.
Limestone
Gas bubbles
"Holes," like
Swiss cheese,
in the rock.
Basalt
Glassy surface
A shiny and
smooth surface,
like colored
glass.
Obsidian
Ribbonlike
layers
Straight or
wavy stripes of
different colors
in the rock.
Gneiss
Sand or
pebbles
Individual
stones, pebbles,
or sand grains
visible in the
rock.
Conglomerate
Think **and actually attempt an answer:
Which rock do you think takes the least amount of time to weather? Sedimentary
Do you think igneous rocks weather more slowly or more quickly than this type of rock? Slowly –It is the
hardest rock!
Back to the interactive lesson:
Describe the following rocks:
Conglomerate—Sedimentary—Finding a bed of this means a river or beach once existed there, sand and
pebbles are easily seen, sediments are compacted by the waves of water compressing sediments together
Limestone—Sedimentary—found near lakes and oceans, fossils form easily in limestone (as shells and
other hard parts cement with other sediments during formation and are not destroyed in the process)
Basalt—Extrusive Igneous—known for its gas bubbles from gas escaping lava as it cools, dark in color,
makes up the ocean floor, most common type of rock found in the earth’s crust
Gneiss –Metamorphic--Ribbon like layers, squeezed and heated and then uplifted
Obsidian—Extrusive Igneous--lava from a volcano that has cooled super fast, very sharp, glassy looking
Marble—Metamorphic—Limestone that has been heated and pressurized, crystals, can be pure white or
swirls of color, used in construction/sculpture
Take the quiz: Write your score here ______________
How Rocks Change
Heat and Pressure:
Explain, in detail, HOW rocks change beneath the surface of the earth. *Include how far below the surface this
occurs.




Movement in the crust pulls rocks down under the surface of the earth (100-200 Km or 62-124
miles)
Temperature dramatically increases the further the rock is pulled down--hot enough to melt most
rocks. BUT before the melting point is reached, a rock (solid) can morph from one type to another
without melting.
Pressure caused by tons of other rocks pressing down on it from above is an additional factor
Heat and pressure usually work together to MORPH or Change the rocks.
*Make sure to watch the simulation!!!!
Melting:
What temperature is required to melt rocks turning them into magma?
Between 600 and 1,300 degrees Celsius (1,100 and 2,400 degrees Fahrenheit)
Cooling:
Explain the difference between Extrusive Igneous Rocks and Intrusive Igneous Rocks:
Extrusive igneous rock—Cools quickly, extruded, or pushed, out of the earth's interior and cools outside
of or very near the earth's surface.
Intrusive igneous rock—Cools slowly, intrudes, or pushes, into the earth's interior and cools beneath the
surface--pushed slowly upward toward the earth's surface over hundreds, thousands, or even millions of
years, thus cooling very slowly. * A rock melting (into magma eventually) under the conditions of
metamorphism then slowly cooling magma is a great example.
*Make sure to watch the simulations!!!
Weathering and Erosion
Explain:
Weathering—The break down of a rock into sediments by wind, rain, running water, temperature
changes (freezing/thawing), sun **Think, water breaks limestone down easy (under the ground) to form
caves, water seeps in the cracks of rocks then freezes to break apart the rock, the sun evaporates water in
rocks making them dry and crumbly, etc. ALL weathering!
**BTW, ALL of the above are examples of MECHANICAL/PHYSICAL Weathering (as opposed to
Chemical Weathering –dissolving minerals ie. Oxidation, thus making a weaker rock to break apart).
Erosion—The continued breakdown of sediment due to the transportation of that sediment.
Compaction and Cementation (Lithification)
Explain:
 Sediment builds up in oceans, lakes, and valleys in layers
 Layers weigh down the material underneath. compacting the sediment
 Water passing through the spaces in between the particles helps to cement them together even
more.
*Make sure to watch the simulations!!!
Take the quiz: Write your score here ______________
The Rock Cycle Diagram
Click around the diagram to familiarize yourself with the processes and the examples.
Think **and actually attempt an answer:
Which type of rock is most likely to contain a fossil? Sedimentary
Why?
It is the softest, thus when it is formed it is the least likely to destroy the hard parts of a fossil
Which of the following do you think is NOT a major factor that can cause one type of rock to change into
another?
*CIRCLE
Temperature, Pressure, Water, Erosion
Why? All are FACTORS, but water is only ONE weathering agent. All other choices are steps that
more largely contribute to the changing of rocks from one to the other.
Take the quiz: Write your score here ______________
Final procedure:
1. Click to complete the final chapter which is the “Test Your Skills” chapter.
2. Type in ALL names who are completing the interactive lesson with you where it asks for this
information.
3. Take the quiz.
4. Print the results!!!
5. Turn in your paper to the TURN IN BIN for a grade.
6. Go to
http://www.classzone.com/books/earth_science/terc/content/investigations/es0602/es0602page02.cfm
and follow this interaction to see how well you know it!