chapter 4. classifying rocks rocks are made up of two or minerals. about 20 minerals make up most...
TRANSCRIPT
![Page 1: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/1.jpg)
ROCKSChapter 4
![Page 2: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/2.jpg)
Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the
earth’s rocks. When studying rocks, geologists
observe the mineral composition, color and texture of the rock.
This rock contains
three minerals.
![Page 3: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/3.jpg)
Rock color A rock’s color can indicate the rock’s
mineral composition. Certain minerals are light in color while other minerals are dark in color.
Granites are usually light Basalts are usually dark
![Page 4: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/4.jpg)
Rock Texture
Texture involves 3 components:
1) Grain size2) Grain shape3) Grain pattern
Fine grained Coarse grained
Rounded grains Jagged grains
Nonbanded banded
![Page 5: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/5.jpg)
Three Groups of Rocks
Igneous – form from the cooling of magma or lava
Sedimentary – form when particles of rocks are pressed & cemented together
Metamorphic – when existing rocks are changed by heat, pressure, or chemical reactions.
![Page 6: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/6.jpg)
This is NOT the correct answer!
![Page 7: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/7.jpg)
IGNEOUS ROCKS Igneous rocks are
classified according to their origin, texture, and mineral composition.
ORIGIN:
Extrusive – formed from lava that has erupted.
Intrusive – formed when magma hardens under the earth’s surface.
Basalt
Granite
Most commonIntrusive rock
Most common Extrusive rock
![Page 8: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/8.jpg)
Extrusive vs. Intrusive Extrusive Rapid cooling Small crystal size;
fine grained Can have a glassy
texture
Intrusive Slow cooling Larger crystals;
coarse grained
![Page 9: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/9.jpg)
![Page 10: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/10.jpg)
Types of Magma/Lava Different
compositions of lava or magma determine the types of igneous rocks formed.
Magma that contains SILICA will form light colored rocks such as
granite.
If the magma is low in silica will form dark colored rocks
such as basalt.
![Page 11: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/11.jpg)
Uses of Igneous Rock Igneous rock has
been used for thousands of years for buildings and statues. Granite is the most widely used igneous rock.
![Page 12: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/12.jpg)
SEDIMENTARY ROCKS Sediments are small bits & pieces of
rocks, shells, sand, bones, or parts of plants.
Can you see the shells?
This is called silt
Sediments can be carriedaway by water to be deposited somewhere else.
![Page 13: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/13.jpg)
From Sediment to Rock
• Particles are carried away by wind or water• Particles are deposited• DEPOSITION
ErosionSteps 1 & 2
Step 3
Step 4
![Page 14: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/14.jpg)
Sedimentary rock formation
![Page 15: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/15.jpg)
![Page 16: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/16.jpg)
Formation under water
![Page 17: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/17.jpg)
Three Major Types of Sedimentary Rocks
Clastic
• Rock formed by rock fragments that are cemented together; sometimes visible large fragments, sometimes small, fine fragments
• Two common types are conglomerates, sandstone, breccias
Organic •Rocks formed by the remains of plants/animals that are cemented together.•Two common types are coal and limestone
Chemical •Formed when minerals dissolved in water are crystallized when the water evaporates away•Calcite and Halite can form this way.
![Page 18: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/18.jpg)
CLASTIC SEDIMENTARY ROCKS
These are conglomerates
This is a breccia.Notice the jaggededges.
This is sandstone.The individual fragmentsAre not easily seen.
This is shale, splitseasily into thin sheets.
![Page 19: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/19.jpg)
ORGANIC SEDIMENTARY ROCKS
Limestone – forms in the ocean from shells, corals, calcite skeletons being compacted
Coquina- a special type of limestoneIn which shells can be easily seen
Fossils are found mainlyIn sedimentary rocks.
Coal is one of the most important organic rocks.
![Page 20: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/20.jpg)
The formation of COAL
![Page 21: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/21.jpg)
Coal is made from once living plants & animals.
![Page 22: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/22.jpg)
Limestone is formed from corals, and other sea animals.
These shells and animal remains get crushed and cemented together over time to form limestone.
![Page 23: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/23.jpg)
Limestone formations
These are called pancake
rocks!
These are
located in
Vietnam.
![Page 24: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/24.jpg)
More limestone formations
Many cave formations are
made of limestone.
Here are some hot springs in
limestone.
![Page 25: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/25.jpg)
Chemical Sedimentary Rocks Gypsum and Halite are two of the most
common chemical sedimentary rocks. They can also be minerals! They formed by dissolved chemicals
crystallizing as water evaporates. For this reason they are sometimes
called EVAPORITES.
![Page 26: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/26.jpg)
This is GYPSUM in a cave in New Mexico. Gypsum is Calcium Sulfate. It is usedIn plaster of paris, drywall, and Cement.
This is a chemical form of limestone. It is called TUFA.
![Page 27: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/27.jpg)
Coral Reefs are responsible for much of the limestone on earth.
Coral is an animal much like a sea anenome. They have tentacles and eat plankton. To protect their soft bodies they secrete a hard substance called CALCITE. When they die, these calcite shells remain.
![Page 28: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/28.jpg)
Ancient Coral Reef vs. Living Coral Reef
Great Barrier ReefAustralia
![Page 29: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/29.jpg)
METAMORPHIC ROCKS Heat & pressure deep in the earth can change
any rock into a metamorphic rock. They can form from igneous, sedimentary and other metamorphic rocks.
Extremely high temps and pressures deep in the earth can actually change a rocks mineral composition.
![Page 30: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/30.jpg)
Two Types of Metamorphic Rocks FOLIATED
Rocks grains are arranged in
parallel bands or layersCommon
examples:Slate, gneiss,
schist
NONFOLIATEDGrains are
arranged randomly.Common
examples:Marble, quartzite
![Page 31: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/31.jpg)
Increasing pressure causes greater foliation
Increasing Pressure
![Page 32: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/32.jpg)
SHALE SLATE SCHIST GNEISS
SEDIMENTARY
ROCK
![Page 33: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/33.jpg)
With pressure, granite becomes gneiss. Igneous rock is changed to a metamorphic rock.
![Page 34: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/34.jpg)
Nonfoliated Metamorphic Rocks
![Page 35: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/35.jpg)
USES OF METAMORPHIC ROCK
![Page 36: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/36.jpg)
World’s Largest Marble QuarryTate, GA
![Page 37: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/37.jpg)
Uses of SLATE
![Page 38: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/38.jpg)
![Page 39: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/39.jpg)
The Rock Cycle
It is a series of processes
in the earth’s crust, mantle
and on the earth’s surface
that SLOWLY change
rocks from one kind to
another.
![Page 40: Chapter 4. Classifying rocks Rocks are made up of two or minerals. About 20 minerals make up most of the earth’s rocks. When studying rocks, geologists](https://reader036.vdocuments.us/reader036/viewer/2022062315/56649cb75503460f9497c721/html5/thumbnails/40.jpg)