SEDIMENTARY ROCKS PART 2
CHEMICAL ROCKS
1. CHEMICALsedimentary rocks form when minerals DISSOLVED in a solution CRYSTALLIZE.
2. Chemical LIMESTONE forms when the mineral CALCITE that is dissolved in LAKES,
SEAS, or UNDERGROUNDwater forms CRYSTALS.
3. Another way chemical rocks can form is when water EVAPORATESfrom seas or lakes,
leavingMINERALdeposits behind. ROCK salt from the mineral HALITE
forms in this way.
USES OF SEDIMENTARY ROCKS
1. Like igneous rocks, sedimentary rocks have been used throughout history for BUILDING
materials and TOOLS.
2. FLINThas been used for thousands of years to make ARROWHEADS.
3. SANDSTONEand LIMESTONE are used in building materials.
4. LIMESTONE is also used in making CEMENT and STEEL.
LIMESTONE FROM CORAL REEFS p. 109
1. A coral reef formsORGANIC limestone.
2. Organic limestone can be found in Alabama and many other states such as Texas, Illinois, Indiana
and New Mexico because for MILLIONS of years, the central United States was
A WARMclimate covered by SHALLOWseas.
3. This explains how thick deposits of LIMESTONEformed byCORALreefs are
found 2,600meters above SEAlevel!
METAMORPHIC ROCKS p. 110-112
1. Two forces that can change any existing rock into metamorphic rocks:
HEAT andPRESSURE.
2. When a rock is changed into a metamorphic rock, its APPEARANCE, TEXTURE,
CRYSTALstructure, and CHEMICALcontent change.
3. Deep inside the Earth, heat from pockets of MAGMA or the MANTLEproduce
METAMORPHIC rocks.
4. TheDEEPERa rock is buried, the greater the PRESSURE on that rock.
TYPES OF METAMORPHIC ROCKS
1. Geologists classify metamorphic rocks according tothe ARRANGEMENT of the GRAINS
thatmake up the rock.
2. Metamorphic rocks with grains arranged in parallel layers are called FOLIATED,
which comes from the Latin word forLEAF.
3. Examples of foliated metamorphic rock on p. 111 are GNEISS and SLATE.
4. GNEISS forms from the igneous rock granite.
5. Metamorphic rocks with grains arranged randomly are called NON-FOLIATED.
6. Two examples of non-foliated metamorphic rock on p. 111 are QUARTZITE and MARBLE.
7. QUARTZITEforms from the sedimentary rock sandstone.
8. Classify each metamorphic rock as FOLIATED or NON-FOLIATED
NON-FOLIATED--Marble FOLIATED--Slate FOLIATED--Gneiss
USES OF METAMORPHIC ROCK
1. The 2 most useful metamorphic rocks are MARBLEand SLATE.
2. Marble forms from LIMESTONE.
3. Marble is used in many building materials and statues because it can be CUT into thin slabs,
CARVED into many shapes, is easy to POLISH and comes in a variety of COLORS.
4. Because SLATE comes in a variety of COLORSand SPLITSeasil into FLAT pieces, it is used in flooring,
ROOFING, outdoor walkways, CHALKBOARDS, and TRIMfor stone buildings.