Topic 3 Rocks and Minerals

Question 1

What is the crust mainly made up of?

Answer 1

75% of crust composed of oxygen and silicon, 8% Aluminum, and 5% iron

Question 2

What are the four major types of material that form Earth’s surface?

Answer 2

Rock, sediment, organic matter, and water

Question 3

What is rock?

Answer 3

a solid, cohesive aggregate of grains composed of one or more materials. Grains are essentially all inorganic

Question 4

What is sediment?

Answer 4

Generally, unconsolidated inorganic materials originally derived from the fractionation of rocks.

Question 5

What is organic matter?

Answer 5

Deposits composed of mainly dead or decaying matter from organisms (such as plants or animals). Includes upper horizons of soil, peat, shell beds, organic muds, Also includes coal and oil shales (sometimes classified as rocks)

Question 6

How much of Earth’s surface is covered in water?

Answer 6

70% of earth’s surface is covered in water

Question 7

What are minerals?

Answer 7

Any naturally occuring inorganic, solid substance possesing a definite chemical composition and characteristics atomic structure (usually crystaline)

Question 8

what are common types of minerals?

Answer 8

Felsic and Mafic minerals

Question 9

felsic Minerals

Answer 9

Light in colour or white mineral. e.g. Quartz, plagioclase, orthoclase

Question 10

Mafic Minerals

Answer 10

Dark green or black in colour mineral. e.g. Basalt, olivine, hornblende, augite

Question 11

What are the 3 types of rocks?

Answer 11

igneous, sedimentary, and metamorphic rock

Question 12

What are the two types of igneous rock?

Answer 12

Intrusive and extrusive

Question 13

Intrusive (plutonic) igneous rocks

Answer 13

Magma cools slowly below the surface, creates large crystals (Dikes, sills, and batholith/large pool)

Question 14

Extrusive (volcanic) igneous rocks

Answer 14

Magma cools rapidly above the surface, creates small crystals

Question 15

Magma rich in Fe and Mg

Answer 15

Have a high content of mafic minerals (dark coloured rock)

Question 16

Magma deficient in Fe and Mg, yet rich in Si and Al

Answer 16

produce abundant felsic minerals (Light coloured rocks)

Question 17

How are igneous rocks classified?

Answer 17

Based on the relative abundances of felsic and mafic mineral species in the rocks

Question 18

Types of weathering

Answer 18

Chemical weathering and physical weathering

Question 19

Chemical weathering

Answer 19

Examples: oxidation: addition of oxygen to minerals (e.g. Rust), Hydrolysis: addition of water to minerals (e.g. Granite reacts with water creating clay)

Question 20

Physical weathering

Answer 20

Breaks off individual mineral grains (fragmentation), facilitates chemical weathering

Question 21

formation of sedimentary rock

Answer 21

Weathering of rocks create small mineral particles; particles are transported by air, water or gravity; sediment is deposited in various environments; strata becomes burried; strata hardens, compacts and cemented to form sedimentary rock

simplified: Erosion, Deposition, compaction, cementation

Question 22

Types of sedimentary rocks

Answer 22

Clastic, precipitate, fossils, organic

Question 23

Clastic sedimentary rock

Answer 23

Inorganic rock and mineral fragments

Question 24

Precipitate sedimentary rock

Answer 24

Chemical precipitation of inorganic compounds from solution or as hard parts of organisms (e.g. shells, calcium carbonate precipitated on sea or lake floors)

Question 25

fossil sedimentary rock

Answer 25

organisms preserved as fossils when their bodies are burried by layers of sedimentary rock

Question 26

organic sedimentary rock

Answer 26

fragments of tissues of organisms (e.g. peat moss) can harden into coal

Question 27

Metamorphic Rock formation

Answer 27

when other types of rock are altered by intense heat and/or pressure (plate tectonics); often producing a harder, changed form of rock; recrystallization of existing materials/ formation of new crystals (e.g. mica from clays); foliation (preferred orientation of minerals within a rock); mineral layering due to different melting temperatures/ directional pressure (tectonic stress); classified by degree of metamorphism (grade)

Question 28

The Rock Cycle

Answer 28

Extrusive igneous rocks break down into small fragments, nature may move it, fragments settle, layering into sediment, get burried and compressed, turning into sedimentary rock, which is transformed by extreme heat and pressure through metamorphism, turning to metamorphic rock, which is melted by the even hotter heat and pressure turning to intrusive or extrusive igneous as it’s lifted: extrusive then repeats the cycle, intrusive is covered under the surface until it is revealed and which will break apart and too will repeat the cycle.