Regents Earth Science
Mr. Ferro
Name ____________
Geological Junk Food
Introduction
Igneous rocks are divided into two groups. The first group is called intrusive rocks because they
form inside the Earth. Intrusive rocks crystallize slowly resulting in rocks with large crystals.
When the magma breaks through the crust as lava and solidifies, the rocks formed are called
extrusive rocks. These rocks solidify so quickly that the crystals are very small or don’t even
form at all.
Sedimentary rocks are deposited in horizontal layers. Studies of modern environments where
deposition occurs help geologists understand conditions that existed long ago when sedimentary
rocks were deposited. For example, modern organisms that live in tropical seas are closely
related to fossils found in some limestone deposits. Therefore, geologists theorize that some
types of limestone formed in tropical seas. A rock that contains fossils is almost certainly a
sedimentary rock.
Metamorphic rocks are rocks that were changed by high heat or pressure. Like igneous rocks,
metamorphic rocks are usually composed of intergrown crystals. But, the crystals are pushed
together by pressure to form bands or layers of mineral crystals (this is called foliation).
Metamorphic rocks can also be bent or distorted.
Materials and Methods
Wash hands before making cookies!
Metamorphic Outcrop Chocolate
3 oz white chocolate chip minerals
3 oz chocolate chip minerals
3 oz of any of the other mineral chips
Place minerals in separate bowls. Place bowls in microwave oven for one minute to melt
minerals. Stir and repeat until melted. When minerals are melted, pour chocolate minerals on the
wax paper. Stir lightly to swirl the minerals, not to mix them. Remember, you want to create a
model of a metamorphic rock. Refrigerate until hard. Record your observations in the proper
section.
Sedimentary Rock Cookies
1/3 of a stick of margarine
10 oz package of marshmallows
6 ½ cup rice crispy
½ oz chocolate sediments
Melt margarine and marshmallows the big bowl by placing in microwave oven for 35 seconds.
Heat again for 20 seconds or until melted. Stir in rice crispy cereal. Form mixture by layering on
wax paper. Sprinkle "sediments" in layers on top of the rice crispy sediment layer.
Observations and Data
Record the defining rock features that you see in your cookies that are also found in sedimentary
and metamorphic rocks.
Conclusions
In a paragraph or two describe how your “rock” represents a specific rock type. Answer the
following questions.
1. Which is the best description of the properties of basalt?
a. fine-grained and mafic
b. fine-grained and felsic
c. course-grained and mafic
d. course-grained and felsic
2. The particles below are drawn to scale. What specific rock is formed when these sized
particles become lithofied.
. . .
..
. . . .. ..
3. It is possible to have a rock model represent more then one rock type. For example, the
metamorphic outcrop chocolate you made can also be a model for igneous rocks because
you melted and solidified chocolate (magma). How can the sedimentary rock cookies (rice
crispy treats) you made represent another type of rock?
4. What type of cookie (or other food) represents metamorphic rock and why?
5. Smores are marshmallows and chocolate sandwiched between graham crackers and lightly
toasted. What type of rock does this represent and why?