Earth Composition 2

Question 1

What are the two main types of rocks based on their formation environment?

Answer 1

Endogenous (internal processes) and Exogenous (external processes)

Question 2

What is the rock cycle?

Answer 2

The continuous process of rock formation, breakdown, and reformation involving igneous, sedimentary, and metamorphic rocks

Question 3

What is petrology?

Answer 3

The scientific study of rocks and the conditions under which they form

Question 4

What is the difference between weathering and erosion?

Answer 4

Weathering breaks down rocks without movement; erosion involves the removal and transport of rock material

Question 5

What are the two types of weathering?

Answer 5

Physical (mechanical) and Chemical

Question 6

What is diagenesis?

Answer 6

The suite of processes that convert sediments into sedimentary rock

Question 7

What are the key diagenetic processes?

Answer 7

Compaction, cementation, dissolution, transformation, and recrystallization

Question 8

What are detrital sedimentary rocks formed from?

Answer 8

Fragments (clasts) of pre-existing rocks

Question 9

What is sedimentary differentiation?

Answer 9

Sorting of sediment components by solubility and energy of the environment

Question 10

Name two types of chemical sedimentary rocks.

Answer 10

Limestone (calcareous) and evaporites (e.g. gypsum, halite)

Question 11

What is coalification?

Answer 11

Transformation of plant material into coal under pressure and heat

Question 12

List the types of coal in increasing order of carbon content.

Answer 12

Peat, lignite, sub-bituminous, bituminous, anthracite

Question 13

What conditions are needed for petroleum formation?

Answer 13

Accumulation of plankton, burial, migration through rocks, presence of reservoir and cap rock

Question 14

How are igneous rocks formed?

Answer 14

By the cooling and solidification of magma

Question 15

What is the difference between intrusive and extrusive igneous rocks?

Answer 15

Intrusive rocks cool slowly underground; extrusive rocks cool quickly at the surface

Question 16

What factors affect magma formation?

Answer 16

Temperature, pressure, and water content

Question 17

What is Bowen’s Reaction Series?

Answer 17

A sequence describing the order of silicate mineral crystallization from magma

Question 18

What are the two branches of Bowen’s Reaction Series?

Answer 18

Discontinuous and Continuous

Question 19

What is magmatic differentiation?

Answer 19

Process by which magma composition changes due to crystal fractionation

Question 20

What is magma assimilation?

Answer 20

Incorporation of surrounding rock into magma altering its composition

Question 21

What is magma mixing?

Answer 21

Combining of two different magmas to form a new composition

Question 22

Where do basaltic magmas commonly form?

Answer 22

At mid-ocean ridges and hot spots

Question 23

Where do andesitic magmas form?

Answer 23

At subduction zones

Question 24

Where do rhyolitic magmas form?

Answer 24

In orogenic zones (e.g. continental subduction)

Question 25

What type of volcano forms from basaltic lava flows?

Answer 25

Shield volcano

Question 26

Which volcano type is built from pyroclastic material?

Answer 26

Cinder cone

Question 27

What is a stratovolcano?

Answer 27

A large volcano with alternating layers of lava and ash

Question 28

What are the main volcanic materials?

Answer 28

Lava, pyroclastic material, and lahars

Question 29

What is metamorphism?

Answer 29

The transformation of rocks under heat and pressure without melting

Question 30

What is anatexis?

Answer 30

Partial melting of a rock during high-grade metamorphism

Question 31

Name three agents of metamorphism.

Answer 31

Heat, pressure, and chemically active fluids

Question 32

What is foliation in metamorphic rocks?

Answer 32

Alignment of minerals into planes due to directional pressure

Question 33

What are the two broad categories of metamorphism?

Answer 33

Local (contact, dynamic) and regional (burial, hydrothermal)

Question 34

What is a metamorphic facies?

Answer 34

A set of mineral assemblages formed under similar pressures and temperatures

Question 35

Which facies are associated with high-pressure, low-temperature?

Answer 35

Blueschist and eclogite

Question 36

Which facies are associated with contact metamorphism?

Answer 36

Hornfels and sanidinite

Question 37

Which facies form in medium pressure and temperature?

Answer 37

Greenschist, amphibolite, granulite

Question 38

What is a protolith?

Answer 38

The original rock before metamorphism

Question 39

What determines the grade of metamorphism?

Answer 39

Temperature and pressure intensity

Question 40

What is recrystallization in metamorphism?

Answer 40

Growth of new minerals from old ones under new conditions