Rock Formation Q & A

ROCK FORMATIONROCK FORMATION

Multiple ChoiceMultiple ChoiceIdentify the choice that Identify the choice that bestbest completes the completes the statement or answers the statement or answers the question.question.

Intrusive Rocks• As magma cools, atoms and compounds in the

liquid rearrange themselves into new crystals called mineral grains.

• Rocks form as these mineral grains grow together.

Igneous RocksIgneous Rocks

• Rocks that form from magma below the surface are called intrusive igneous rocks.

1.1. Magma that cools below Earth’s Magma that cools below Earth’s surface forms ________ rock.surface forms ________ rock.

Answer?Answer?

D.D. INTRUSIVE IGNEOUSINTRUSIVE IGNEOUS

• The rock cycle shows how rock can be weathered to small rock and mineral grains. This process, which breaks rocks into smaller pieces, is called weathering.

• The movement of weathered material is called erosion.

• Where sediments are deposited, layer upon layer builds up. Pressure from the Pressure from the upper layers pushes down on the lower upper layers pushes down on the lower layers. layers. If the sediments are small, they can stick together and form solid rock. This process is called compaction.

2.2. The processes involved in the The processes involved in the rock cycle include all of the rock cycle include all of the following EXCEPT _______ .following EXCEPT _______ .

Answer?Answer?

A.A. CONDENSATIONCONDENSATION

When mineral grains line up in parallel layers, the metamorphic rock is said to have a foliated texture. Two examples of foliated rocks are slate and gneiss.

3. 3. Foliated rocks are distinguished Foliated rocks are distinguished by _____________ . by _____________ .

Answer?Answer?

B.B. LAYERSLAYERS

Extrusive igneous rocks are formed as lava cools on the surface of Earth. When lava flows on the surface, it is exposed to air and water, and cools quickly under these conditions.

44. . Lava that cools quickly forms Lava that cools quickly forms __________ rocks.__________ rocks.

Answer?Answer?

B. B. EXTRUSIVE IGNEOUSEXTRUSIVE IGNEOUS

Fluids, which are mostly water with dissolved elements and compounds, can react chemically with a rock and change its composition, especially when hot. Heat, pressure, and hot fluids trigger the changes. In the presence of hot, water-rich fluids, solid rock can change in mineral composition without having to melt.

5. 5. Metamorphic rocks can be Metamorphic rocks can be formed from all of the following formed from all of the following EXCEPT _____________.EXCEPT _____________.

Answer?Answer?

A.A. THE FORMATION OF MINERALS THE FORMATION OF MINERALS FROM SOLUTIONSFROM SOLUTIONS

In some metamorphic rocks, layering does not occur. The mineral grains grow and rearrange, but they don’t form layers. This process produces a nonfoliated texture.

• Metamorphic rocks form from igneous, sedimentary, or other metamorphic rocks. Each resulting rock can be classified according to its composition and texture. When mineral grains line up in parallel layers, the metamorphic rock is said to have a foliated texture.

6. 6. A classification of metamorphic A classification of metamorphic rocks would include whether they rocks would include whether they are _______.are _______.

Answer?Answer?

C.C. FOLIATED OR NONFOLIATED FOLIATED OR NONFOLIATED

• Sediments are loose materials such as rock fragments, mineral grains, and bits of shell that have been moved by wind, water, ice, or gravity. Sediments come from already-existing rocks that are weathered and eroded. Sedimentary rock forms when sediments are pressed and cemented together, or when minerals form from solutions

75 % of the rocks exposed at the surface are sedimentary rocks. Sedimentary rocks often form as layers.

7.7. Sedimentary rocks are __________.Sedimentary rocks are __________.

Answer?Answer?

D. D. FORMED FROM ALREADY FORMED FROM ALREADY EXISTING ROCKS THAT ARE EXISTING ROCKS THAT ARE WEATHERED AND ERODEDWEATHERED AND ERODED

Basaltic (buh SAWL tihk) igneous rocks are dense, dark-colored rocks. They form from magma that is rich in iron and magnesium and poor in silica, which is the compound SiO2.

Granitic igneous rocks are light-colored rocks of lower density than basaltic rocks. Granitic magma is thick and stiff and contains lots of silica but lesser amounts of iron and magnesium.

Andesitic igneous rocks have mineral compositions between those of basaltic and granitic rocks.

8. 8. Andesitic rocks have mineral Andesitic rocks have mineral compositions between those of compositions between those of ______ and basaltic______ and basaltic..

Answer?Answer?

C. C. GRANITICGRANITIC

Matter and the Rock Cycle

The rock cycle shows how rock can be weathered to small rock and mineral grains. This material then can be eroded and carried away by wind, water, or ice.

This illustrates the principle of conservation of matter. The changes that take place in the rock cycle never destroy or create matter. The elements are just redistributed in other forms.

9. 9. The changes that take place in the The changes that take place in the rock cycle ___________.rock cycle ___________.

Answer?Answer?

D.D. NEVER CREATE OR DESTROY NEVER CREATE OR DESTROY MATTERMATTER

Detrital Sedimentary Rocks

The word detrital (dih TRI tul) comes from the Latin word detritus, which means “to wear away.”

Detrital sedimentary rocks are made from the broken fragments of other rocks.

10.10. Detrital rocks are ________.Detrital rocks are ________.

Answer?Answer?

A.A. MADE FROM THE MADE FROM THE FRAGMENTS OF OTHER FRAGMENTS OF OTHER ROCKSROCKS

11.11. The rock cycle indicates that each The rock cycle indicates that each type of rock can _________.type of rock can _________.

Answer?Answer?

Rocks change by many processes. For example, a sedimentary rock can change by heat and pressure to form a metamorphic rock. The metamorphic rock then can melt and later cool to form an igneous rock.

The igneous rock then could be broken into fragments by weathering and erode away.

(continued)(continued)

The fragments might later compact and cement together to form another sedimentary rock. Any given rock can change into any of the three major rock types. A rock even can transform into another rock of the same type.

D.D. ALL OF THE ABOVE ALL OF THE ABOVE

12. 12. Pumice, obsidian, and scoria are Pumice, obsidian, and scoria are kinds of ___________.kinds of ___________.

Answer?Answer?

Volcanic Glass Pumice, obsidian, and scoria are examples of volcanic glass. These rocks cooled so quickly that few or no mineral grains formed. Most of the atoms in these rocks are not arranged in orderly patterns, and few crystals are present. In the case of pumice and scoria, gases become trapped in the gooey molten material as it cools. Holes are left behind where the rock formed around the pockets of gas.

B. B. VOLCANIC GLASSVOLCANIC GLASS

13.13. A rock is _________. A rock is _________.

Answer?Answer?

What is a rock?—Common Rocks

Most rock used for building stone contains one or more common minerals, called rock-forming minerals, such as quartz, feldspar, mica, or calcite. When you look closely, the sparkles you see are individual crystals of minerals.

A rock is a mixture of such minerals, rock fragments, volcanic glass, organic matter, or other natural materials.

B.B. A MIXTURE OF MINERALS, A MIXTURE OF MINERALS, ORGANIC MATTER, VOLCANIC ORGANIC MATTER, VOLCANIC GLASS, OR OTHER GLASS, OR OTHER MATERIALS.MATERIALS.

14. 14. The crystals that form in slowly The crystals that form in slowly cooling magma are generally cooling magma are generally _________._________.

Answer?Answer?

Magma Because magma is less dense than surrounding solid rock, it is forced upward toward the surface. When magma reaches Earth’s surface and flows from volcanoes, it is called lava. As magma cools, atoms and compounds in the liquid rearrange themselves into new crystals called mineral grains. When cooled slowly these crystals are generally large.

D. D. LARGELARGE

15. 15. Detrital rocks are named Detrital rocks are named according to__________ . according to__________ .

Answer?Answer?

Shape and Size of Sediments Detrital rocks have granular textures, much like granulated sugar. They are named according to the shapes and sizes of the sediments that form them.

C. C. THE SIZE AND SHAPE OF THE SIZE AND SHAPE OF THERE SEDIMENTS.THERE SEDIMENTS.

16. 16. Sedimentary rocks are usually Sedimentary rocks are usually classified as ____________.classified as ____________.

Answer?Answer?

Classifying Sedimentary Rocks

Like igneous and metamorphic rocks, sedimentary rocks are classified by their composition and by the manner in which they formed. Sedimentary rocks usually are classified as detrital, chemical, or organic.

D. D. DETRITAL, CHEMICAL, OR DETRITAL, CHEMICAL, OR ORGANICORGANIC

MatchingMatching

Match the terms with their descriptions Match the terms with their descriptions below.below.

______ 17. Rocks formed by changes ______ 17. Rocks formed by changes in heat and pressure or the pressure in heat and pressure or the pressure of hot, watery fluids.of hot, watery fluids.

• Rocks that have changed because of changes in temperature and pressure or the presence of hot watery fluids are called metamorphic rocks.

B. METAMORPHIC ROCKSB. METAMORPHIC ROCKS

18. 18. Rocks formed from molten Rocks formed from molten materialsmaterials

• When hot magma cools and hardens, it forms igneous (IHG nee us) rock.

J. IGNEOUS ROCKSJ. IGNEOUS ROCKS

19.19. Rocks formed from sedimentsRocks formed from sediments

• Sediments are loose materials such as rock fragments, mineral grains, and bits of shell that have been moved by wind, water, ice, or gravity. Sediments come from already-existing rocks that are weathered and eroded. Sedimentary rock forms when sediments are pressed and cemented together, or when minerals form from solutions

D. SEDIMENTARY ROCKSD. SEDIMENTARY ROCKS

20. Igneous rocks formed on or 20. Igneous rocks formed on or near the earths surfacenear the earths surface

Extrusive Rocks Extrusive igneous rocks are formed as

lava cools on the surface of Earth.

When lava flows on the surface, it is exposed to air and water, and cools quickly under these conditions.

H. EXTRUSIVEH. EXTRUSIVE

21. Layered metamorphic rocks21. Layered metamorphic rocks

Foliated Rocks• When mineral grains line up in

parallel layers, the metamorphic rock is said to have a foliated texture.

• Two examples of foliated rocks are slate and gneiss.

Slate

M. FOLIATEDM. FOLIATED

22.Process by which sediments are 22.Process by which sediments are pressed together to form rock.pressed together to form rock.

Compaction• Where sediments are deposited,

layer upon layer builds up. • Pressure from the upper layers

pushes down on the lower layers.• If the sediments are small, they can

stick together and form solid rock. This process is called compaction.

K. COMPACTIONK. COMPACTION

23. Light colored igneous rocks 23. Light colored igneous rocks with a lower density than basaltic with a lower density than basaltic rocksrocks

Granitic Rocks• Granitic igneous rocks are light-

colored rocks of lower density than basaltic rocks.

• Granitic magma is thick and stiff and contains lots of silica but lesser amounts of iron and magnesium.

A. GRANITIICA. GRANITIIC

24. Dense, dark colored igneous 24. Dense, dark colored igneous rocks.rocks.

Basaltic Rocks• Basaltic (buh SAWL tihk) igneous

rocks are dense, dark-colored rocks. • They form from magma that is rich in

iron and magnesium and poor in silica, which is the compound SiO2.

• The presence of iron and magnesium in minerals in basalt gives basalt its dark color.

• Basaltic lava is fluid and flows freely from volcanoes in Hawaii, such as Kilauea.

F. BASALTICF. BASALTIC

25. Metamorphic rocks that don’t 25. Metamorphic rocks that don’t have layershave layers

Nonfoliated Rocks• In some metamorphic rocks,

layering does not occur.• The mineral grains grow and

rearrange, but they don’t form layers.

• This process produces a nonfoliated texture.

O. NONFOLIATEDO. NONFOLIATED

26. Process by which large 26. Process by which large sediments are glued together by sediments are glued together by dissolved minerals to form rockdissolved minerals to form rock

Cementation• If sediments are large, like sand and

pebbles, pressure alone can’t make then stick together.

• Large sediments have to be cemented together.

• As water moves through soil and rock, it picks up materials released from minerals during weathering.

• The resulting solution of water and dissolved materials moves through open spaces between sediments.

E. CEMENTATIONE. CEMENTATION

27. Igneous rocks formed below 27. Igneous rocks formed below Earth’s surfaceEarth’s surface

Intrusive Rocks• As magma cools, atoms and compounds

in the liquid rearrange themselves into new crystals called mineral grains.

• Rocks form as these mineral grains grow together.


L. INTRUSIVEL. INTRUSIVE

28. Bits of weathered rock, 28. Bits of weathered rock, minerals, grains, plants, and minerals, grains, plants, and animals that have been eroded. animals that have been eroded.

• Sediments are loose materials such as rock fragments, mineral grains, and bits of shell that have been moved by wind, water, ice, or gravity.

• Sediments come from already-existing rocks that are weathered and eroded.

I. SEDIMENTSI. SEDIMENTS

29. Model that illustrates the 29. Model that illustrates the processes that create and change processes that create and change rocks.rocks.

• To show how rocks slowly change through time, scientists have created a model called the rock cycle.

• It illustrates the processes that create and change rocks.

The Rock Cycle

C. ROCK CYCLEC. ROCK CYCLE

30. Magma that reaches Earth’s 30. Magma that reaches Earth’s surface and flows from volcanoes.surface and flows from volcanoes.

Magma

• Because magma is less dense than surrounding solid rock, it is forced upward toward the surface.

• When magma reaches Earth’s surface and flows from volcanoes, it is called lava.

N. LAVAN. LAVA

31. A mixture of minerals, organic 31. A mixture of minerals, organic matter, volcanic glass, or other matter, volcanic glass, or other materials.materials.

• A rock is a mixture of such minerals, rock fragments, volcanic glass, organic matter, or other natural materials.

G. ROCKG. ROCK

IdentifyIdentify

identify each rock as igneous, identify each rock as igneous, metamorphic, or sedimentarymetamorphic, or sedimentary

32. Sandstone32. Sandstone

• Sandstone is a sedimentary rock that’s often composed mostly of quartz grains.

• When sandstone is heated under a lot of pressure, the grains of quartz grow in size and become interlocking, like the pieces of a jigsaw puzzle.

• The resulting rock is called quartzite.

C. SEDIMENTARYC. SEDIMENTARY

33. Granite33. Granite

Granitic Rocks• Granitic igneous rocks are light-

colored rocks of lower density than basaltic rocks.


A. IGNEOUSA. IGNEOUS

34. Rock salt34. Rock salt

Rock Salt• When water that is rich in dissolved

salt evaporates, it often deposits the mineral halite.

• Halite forms rock salt. • Rock salt deposits can range in

thickness from a few meters to more than 400 m.

• Companies mine these deposits because rock salt is an important resource.

35. Obsidian35. Obsidian

• Pumice, obsidian, and scoria are examples of volcanic glass.

• These rocks cooled so quickly that few or no mineral grains formed.

Igneous RocksIgneous Rocks

• Most of the atoms in these rocks are not arranged in orderly patterns, and few crystals are present.

A. IGNEOUSA. IGNEOUS

36. Gneiss36. Gneiss

• The sedimentary rock shale will change into slate.

Metamorphic RocksMetamorphic Rocks

• As increasing pressure and temperature are applied, the slate can change into phyllite, then schist, and eventually gneiss.

Slate

B. METAMORPHICB. METAMORPHIC

37. Slate37. Slate

• The sedimentary rock shale will change into slate.


• As increasing pressure and temperature are applied, the slate can change into phyllite, then schist, and eventually gneiss.

Slate

B. METAMORPHICB. METAMORPHIC

38. Limestone38. Limestone

Limestone• Calcium carbonate is carried in solution

in ocean water.

• When calcium carbonate (CaCO3) comes out of solution as calcite and its many crystals grow together, limestone forms.

• Limestone also can contain other minerals and sediments, but it must be at least 50 percent calcite.

• Limestone usually is deposited on the bottom of lakes or shallow seas.

Short answerShort answer

39. Suppose you found an igneous 39. Suppose you found an igneous rock that had almost even rock that had almost even amounts of silica, iron, and amounts of silica, iron, and magnesium. How would you magnesium. How would you classify this rock? Why?classify this rock? Why?

Andesitic Rocks

Andesitic igneous rocks have mineral compositions between those of basaltic and granitic rocks. Granitic rocks contains lots of silica but lesser amounts of iron and magnesium

Basaltic rocks form from magma that is rich in iron and magnesium and poor in silica


40. How do detrital, chemical, and 40. How do detrital, chemical, and organic sedimentary rocks differ organic sedimentary rocks differ from one another? from one another?

Detrital rocks form by compaction Detrital rocks form by compaction and cementation of rock fragments and cementation of rock fragments and bits of minerals, plant, and and bits of minerals, plant, and animals.animals.

Chemical rocks form from minerals Chemical rocks form from minerals dissolved in solution and deposited dissolved in solution and deposited after evaporation.after evaporation.

Biochemical rocks form from the Biochemical rocks form from the remains of once living things remains of once living things compacted and cemented together.compacted and cemented together.


41. Your friend challenges you to 41. Your friend challenges you to tell what you know about a rock tell what you know about a rock without seeing it. You are given a without seeing it. You are given a one word hint: clasticone word hint: clastic

What can you tell your friend What can you tell your friend about the rock?about the rock?

The word clastic means that the rockThe word clastic means that the rock

has a broken texture. It could be ahas a broken texture. It could be a

detrital sedimentary rock or andetrital sedimentary rock or an

organic rockorganic rock..


42. What makes the rock cycle a 42. What makes the rock cycle a cycle?cycle?

There is no beginning or end. RocksThere is no beginning or end. Rocks

Are constantly changing from one toAre constantly changing from one to

another.another.


43. What is cementation?43. What is cementation?

Cementation occurs when water soaks Cementation occurs when water soaks through rock, picking up atoms and through rock, picking up atoms and molecules released from minerals molecules released from minerals during weathering. This solution of during weathering. This solution of water and dissolved materials moves water and dissolved materials moves through open spaces between through open spaces between sediments. Minerals are deposited sediments. Minerals are deposited between the pieces of sediments, between the pieces of sediments, holding the particles together like glue, holding the particles together like glue, making a detrital sedimentary rock.making a detrital sedimentary rock.

44. Use the information about igneous rocks a-d 44. Use the information about igneous rocks a-d to classify each one as intrusive or extrusive and to classify each one as intrusive or extrusive and basaltic or granitic. Fill in the chart with a,b,c,dbasaltic or granitic. Fill in the chart with a,b,c,dRock a- dark colored large grainsRock a- dark colored large grainsRock b- large crystals, high percentage of silicaRock b- large crystals, high percentage of silicaRock c- fine grained texture, light coloredRock c- fine grained texture, light coloredRock d- from Hawaiian volcano area no visible Rock d- from Hawaiian volcano area no visible crystals crystals

extrusiveextrusive intrusiveintrusive

basalticbasaltic 11 22

graniticgranitic 33 44

• Basaltic (buh SAWL tihk) igneous rocks are dense, dark-colored rocks.


• Granitic igneous rocks are light-colored rocks of lower density than basaltic rocks.


extrusiveextrusive intrusiveintrusive

basalticbasaltic 1 D1 D 2 A2 A

graniticgranitic 3 C3 C 4 B4 B

45.45. In a concept map, would you list In a concept map, would you list basaltic lava under high silica basaltic lava under high silica content or low silica content.content or low silica content.

Basaltic Rocks• Basaltic (buh SAWL tihk) igneous

rocks are dense, dark-colored rocks. • They form from magma that is rich in

iron and magnesium and poor in silica, which is the compound SiO2.

• The presence of iron and magnesium in minerals in basalt gives basalt its dark color.


Low silica contentLow silica content

46. In a concept map, would you list 46. In a concept map, would you list intrusive rocks under rocks that form intrusive rocks under rocks that form above ground or belowabove ground or below

Intrusive Rocks


belowbelow


47. If you were shown one 47. If you were shown one photograph of pumice and one of photograph of pumice and one of granite, how could you distinguish granite, how could you distinguish between the two rocks?between the two rocks?

• In the case of pumice and scoria, gases become trapped in the gooey molten material as it cools.

• Holes are left behind where the rock formed around the pockets of gas.

•These rocks cooled so quickly that few or no mineral grains formed.

• When you look closely, the sparkles you see are individual crystals of minerals.

• Granite has visible crystals.Granite has visible crystals.

Granite has visible crystals; pumice Granite has visible crystals; pumice has no visible mineral grains and has no visible mineral grains and is full of holes.is full of holes.

For each item, tell which would occur For each item, tell which would occur first.first.

48. Molten material cools and forms 48. Molten material cools and forms igneous rocks. Lava flows from a igneous rocks. Lava flows from a volcanovolcano

Formation of Igneous Rocks• When some volcanoes erupt, they

eject a flow of molten rock material.• Molten rock material, called magma,

flows when it is hot and becomes solid when it cools.

• When hot magma cools and hardens, it forms igneous (IHG nee us) rock.

Lava flows from a volcanoLava flows from a volcano

49. Gneiss is formed. The mineral 49. Gneiss is formed. The mineral grains in granite are flattened under grains in granite are flattened under pressure.pressure.

Heat and Pressure


• Schist also can form when basalt is metamorphosed, or changed, and gneiss can come from granite.

The mineral grains in granite are The mineral grains in granite are flattened under pressure.flattened under pressure.


50. Describe the differences among 50. Describe the differences among detrital, chemical, and organic detrital, chemical, and organic rocks.rocks.

Detrital, chemical, and organic rocks are all Detrital, chemical, and organic rocks are all sedimentary rocks, but they form in sedimentary rocks, but they form in different ways. Detrital rocks are made different ways. Detrital rocks are made from broken fragments of rocks. These from broken fragments of rocks. These sediments are compacted and cemented sediments are compacted and cemented together. Chemical sedimentary rocks together. Chemical sedimentary rocks form when minerals are precipitated from form when minerals are precipitated from a solution or are left behind when a a solution or are left behind when a solution evaporates. Organic rocks form solution evaporates. Organic rocks form from the remains of once living things.from the remains of once living things.


51. Where does the rock cycle 51. Where does the rock cycle begin?begin?

It has no beginning; rocks are It has no beginning; rocks are constantly changing from one constantly changing from one type to another.type to another.

True or false rewrite false True or false rewrite false statements to make them correct.statements to make them correct.

52. The composition of a 52. The composition of a sedimentary rock depends upon sedimentary rock depends upon the composition of the rocks and the composition of the rocks and living things its sediments came living things its sediments came from.from.

Classifying Sedimentary Rocks

• Sedimentary rocks can be made of just about any material found in nature.

• Sediments come from weathered and eroded igneous, metamorphic, and sedimentary rocks.

• Sediments also come from the remains of some organisms.

• The composition of a sedimentary rock depends upon the composition of the sediments from which it formed.

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53. All igneous rocks have the same 53. All igneous rocks have the same mineral compositions.mineral compositions.

Classifying Igneous Rocks

• The type of magma that cools to form an igneous rock determines important chemical and physical properties of that rock.

• These include mineral composition, density, color, and melting temperature.

False, igneous rocks are formed from three False, igneous rocks are formed from three basic types of lava basaltic, andesic, and basic types of lava basaltic, andesic, and graniticgranitic

54. Nonfoliated rocks have very narrow 54. Nonfoliated rocks have very narrow layering.layering.

• When mineral grains line up in parallel layers, the metamorphic rock is said to have a foliated texture.

• The mineral grains grow and rearrange, but they don’t form layers, the metamorphic rock is said to have a nonfoliated texture.

False, foliated rocks have tightly False, foliated rocks have tightly pressed together layers (or) pressed together layers (or) nonfoliated rocks have no layersnonfoliated rocks have no layers

55. Sedimentary rock can be formed from 55. Sedimentary rock can be formed from changes in igneous rock, but igneous rock changes in igneous rock, but igneous rock cannot be formed from changes in cannot be formed from changes in sedimentary rock.sedimentary rock.

Any given rock can change into any of the three major rock types. A rock even can transform into another rock of the same type.

False, sedimentary rock can form False, sedimentary rock can form from changes in igneous rock; from changes in igneous rock; igneous rock can form from igneous rock can form from changes in sedimentary rockchanges in sedimentary rock..

56. Metamorphic rocks can form 56. Metamorphic rocks can form from other metamorphic rocks.from other metamorphic rocks.

• Metamorphic rocks can form from igneous, sedimentary, or other metamorphic rocks.

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Rock Formation Q & A

Technology

Transcript of Rock Formation Q & A