exam 1

Question 1

What is Geology?

Answer 1

A branch of science that explains the surface and inside of Earth

Question 2

What are the three inner composition layers of the earth?

Answer 2

Crust, mantle, and core

Question 3

The two other major interior layers based on physical properties are:

Answer 3

Lithosphere and Asthenosphere

Question 4

What characteristics make a mineral a mineral?

Answer 4

• Naturally occurring
• Inorganic
• Has a specific composition and structure
• Have a specific and consistent chemical composition

Question 5

What characteristics make a rock a rock? What are the three types based on how they’re formed?

Answer 5

• Natural, solid materials
• Are composed of one or more naturally occurring solid materials (i.e biogenic materials)
• Igneous, sedimentary, and metamorphic

Question 6

What are the two mineral types?

Answer 6

• Silicates (most common type)
• Nonsilicates (many are economically important

Question 7

What is the formation process of igneous rocks?

Answer 7

Igneous rocks crystallize from cooling magma/lava

Question 8

What is the formation process of sedimentary rocks?

Answer 8

Sedimentary rocks form from the lithification of sediments/fragments and precipitation from liquid water solution

Question 9

What is the formation process of metamorphic rocks?

Answer 9

Metamorphic rocks from from temperature change applied to the rocks, and/or pressure applied to rocks, and/or when rocks interacts with chemically active fluids

Question 10

What is the formation process for silicate minerals?

Answer 10

Silicates crystallize from cooling magma/lava, recrystallize during metamorphic event, or precipitate from liquid water solution (Can be included in igneous, sedi., and meta. rocks)

Question 11

What is the formation process for nonsilicate minerals?

Answer 11

Nonsilicates recrystallize from a metamorphic event, or precipitate from liquid water solution (Can be included in sedi., and meta. rocks)

Question 12

What does coarse-grained mean? (igneous)

Answer 12

Slow cooling

Question 13

What does fine-grained mean? (igneous)

Answer 13

Fast cooling

Question 14

What examples of textures can be used to help identify igneous rocks?

Answer 14

Coarse/fine grain, porphyritic, glassy, vesicular (contains voids/holes, very porous; i.e pumice), & pyroclastic (erupted fragments from volcanoes)

Question 15

What are the two broad chemistry compositions of igneous rocks?

Answer 15

Mafic (black or red, rich in iron and magnesium) or felsic

Question 16

What are the two broad material categories of sedimentary rocks?

Answer 16

Detrital (Sandstone, Siltstone, Shale) or chemical and biochemical (organic; limestone, chert, coal)

Question 17

What examples of textures can be used to help identify sedimentary rocks?

Answer 17

Grain size (small to large), grain sorting (size-range, poorly sorted or well sorted), or grain shape (angular/rounded)

Question 18

What is the composition of metamorphic rocks?

Answer 18

They are inherited from the parent rock (original rock before heat and pressure; may change during metamorphism)

Question 19

What examples of textures can be used to help identify metamorphic rocks?

Answer 19

• Grain shape
• Grain size
• Foliation
  - Foliated
  - Nonfoliated
• Metamorphic grade

Question 20

What are the different types of foliation found in metamorphic rocks?

Answer 20

Slaty cleavage, phyllitic sheen, schistose, and gneissic banding

Question 21

What is low-grade metamorphism?

Answer 21

• Little metamorphic change
• Low temp, low pressure

Question 22

What is high-grade metamorphism?

Answer 22

• Significant metamorphic change
• High temp and/or high pressure

Question 23

What are the characteristics of rocks with a felsic composition?

Answer 23

• Light silicates
• Low in Fe and Mg
• Varying amounts of Al, K, Ca (reactive), Na

Question 24

What are the characteristics of rocks with a mafic composition?

Answer 24

• Dark silicates
• High in Fe and Mg

Question 25

What kinds of minerals are found in Granite/Rhyolite rocks (igneous)?

Answer 25

Light silicates (quartz, feldspar)

Question 26

What kinds of minerals are found in Gabbro/Basalt rocks (igneous)?

Answer 26

Dark silicates (amphibole, pyroxene, olivine)

Question 27

Where does the economic value of rocks come from?

Answer 27

The value of minerals found inside the rocks (Except coal and building and art grade rocks

Question 28

What are some economic values for minerals?

Answer 28

• Precious gems and metals
• Nonprecious but useful minerals and metals
• Food products (i.e table salt)
• Building products (drywall, cement, clay tiles)
• Many other industrial and consumer products