Earth Science, Lecture pt 2 (ch 3)

Question 1

What are the three broad classifications of rocks?

Answer 1

Igneous
Sedimentary
Metamorphic

Question 2

What is a sediment?

Answer 2

Loose fragments of rocks or minerals broken off bedrock

Question 3

How are sediments produced?

Answer 3

Through weathering

Question 4

What is weathering?

Answer 4

The physical or mechanical and/or chemical breakdown of pre-existing rocks

Question 5

The breakdown of intact rock into unconnected clasts (grains or rock fragments)

Answer 5

physical weathering

Question 6

What are the three ways which rocks can be physically weathered?

Answer 6

1. Abrasion
2. Jointing
3. Wedging

Question 7

What is abrasion?

Answer 7

Breakdown of rocks due to material falling or washing down slopes

Question 8

What is jointing?

Answer 8

Natural cracks that form in rocks due to the removal of overburden or due to cooling

Question 9

What is exfoliation jointing?

Answer 9

A type of jointing where rocks can break into thin sheets along pre-dominantly flat-lying parallel joints

Question 10

What is wedging?

Answer 10

Expansion slowly forces open cracks in rocks

Question 11

What are 2 types of wedging?

Answer 11

Frost wedging
Salt wedging

Question 12

What is chemical weathering?

Answer 12

The decomposition of minerals in rocks via chemical reactions

Question 13

What are 3 types of chemical weathering?

Answer 13

1. Dissolution
2. Hydrolysis
3. Oxidation

Question 14

What is dissolution?

Answer 14

Dissolving of minerals into water

Question 15

What is hydrolysis?

Answer 15

A reaction between water and mineral in which water itself is broken down (typically into a weak acid)

Question 16

What is oxidation?

Answer 16

Loss of electrons from an ion (typically ion) to oxygen. Also know as the “rusting” process

Question 17

What are sedimentary rocks?

Answer 17

Rocks formed through the accumulation of sediment or new minerals formed through chemical precipitation or organic
activity

Question 18

What are the 4 classes of sedimentary rocks?

Answer 18

1. Clastic
2. Biochemical
3. Chemical
4. Organic

Question 19

What are igneous rocks?

Answer 19

Rocks that were formed from originally molten states

Question 20

How do igneous rocks form?

Answer 20

They form when minerals crystallize from a cooling
body of magma (molten rock)

Question 21

What two physical properties are igneous rocks characterized by?

Answer 21

1. Texture (grain size)
2. Chemical composition

Question 22

Igneous rocks are also characterized by composition, what does composition mean?

Answer 22

Composition describes the minerals that make up the rock

Question 23

What are the four major magma types?

Answer 23

1. Felsic
2. Intermediate
3. Mafic
4. Ultramafic

Question 24

What are metamorphic rocks?

Answer 24

Pre-existing rocks that are affected by pressure, substantial changes in temperature, or by chemically active fluids (i.e. hot water), but do not melt!

Question 25

What is metamorphism?

Answer 25

The process by which rocks are altered by some combination of heat, pressure, and/or fluids, producing metamorphic rocks

Question 26

What is prolith?

Answer 26

The name of a rock before it was metamorphosed

Question 27

What are two primary environments of metamorphism?

Answer 27

1. Contact
2. Regional

Question 28

What does a slate rock look like?

Answer 28

Fine-grained, low-grade metamorphic rock

Question 29

What does a schist rock look like?

Answer 29

Fine- to coarse-grained, intermediate grade rock

Question 30

What does gneiss rock look like?

Answer 30

Distinct compositional bands of felsic (light) and mafic (dark) minerals

Question 31

What does the nucleus contain?

Answer 31

Protons and neutrons

Question 32

Atoms that have the same # of protons are called

Answer 32

Elements

Question 33

Elements with different # of neutrons are called

Answer 33

Isotopes

Question 34

What are ions?

Answer 34

Charged atoms that have either gained or lost an electron