Chapter 5

Question 1

What are framework grains?

Answer 1

The sediment size of silicate minerals and rock fragments

Question 2

How much does quartz make up of the framework?

Answer 2

50 to 60%

Question 3

How do you distinguish feldspars from quartz under the microscope?

Answer 3

Quartz has undulatory extinction.

Question 4

How do you distinguish between alkali and plagioclase feldspars?

Answer 4

Chemical composition

Question 5

How much do feldspars make up of the framework?

Answer 5

10 to 20%

Question 6

How much do sandstones make up of all sedimentary rocks?

Answer 6

20 to 25%

Question 7

What is the size range for grains in sandstones?

Answer 7

(1/16th-2mm)

Question 8

How much do rock fragments make up of the framework?

Answer 8

15-20%

Question 9

What are the kinds of cement?

Answer 9

Can be of silicate or carbonate origin

Question 10

What is syntaxial overgrowth?

Answer 10

Quartz cement that retains the crystallography of the actual grain

Question 11

How are carbonate cements formed?

Answer 11

precipitated through pore space in framework grains

Question 12

What is a matrix mineral?

Answer 12

Grains in sandstones that are less than 0.03mm that fill space

Question 13

What are the clay mineral groups?

Answer 13

Illite, smectite, kaolinite, chloride

Question 14

What are sandstones that are free of matrix (less than 5%) known as?

Answer 14

Quartzarenites, feldspathic arenites, litic arenites

Question 15

When is the term arkose used?

Answer 15

Arkose is used in feldspathic arenites that is less greater than 25% feldspars

Question 16

When is the term greywacke used?

Answer 16

a matrix rich sandstone that is dark green/gray and very hard

Question 17

What is compositional maturity?

Answer 17

The relative abundance of stable and unstable grains in a sandstone

Question 18

What is a mature sandstone?

Answer 18

A sandstone of mostly quartz

Question 19

What is an immature sandstone?

Answer 19

Sandstone of mostly unstable (feldspars)

Question 20

What is textural maturity?

Answer 20

The relative abundance of matrix and the degree of roundness and sorting of framework grains

Question 21

What is texturally mature?

Answer 21

No clay, well sorted grains that are well rounded

Question 22

What is texturally immature?

Answer 22

Much clay, poorly sorted and angular framework grains

Question 23

What does textural maturity represent?

Answer 23

the degree of sediment transport and reworking

Question 24

What are quartz arenites composed of?

Answer 24

greater than 90% silica grains

Question 25

What are the common colors?

Answer 25

Light gray, can be stained red, pink, yellow, or brown

Question 26

what is the textural maturity of quartz arenites

Answer 26

Mature to super mature

Question 27

What is the percentage of quartz arenites in all sandstones?

Answer 27

!/3rd of all sandstones

Question 28

What is the composition of feldspathic arenites?

Answer 28

less than 90% quartz

Question 29

What are the common colors of feldspathic arenites?

Answer 29

Pink/red light gray to white

Question 30

What is the grain size/ shape of feldspathic arenites?

Answer 30

medium to coarse angular to subangular

Question 31

What is the amount of matrix in f-arenites?

Answer 31

trace amounts to 15%

Question 32

What is the textural maturity of f-arenites?

Answer 32

Immature to sub-mature (wacke)

Question 33

What is the composition of lithic arenites?

Answer 33

More unstable rock fragments than feldspars

Question 34

What is the composition of l-arenites?

Answer 34

immature sandstones

Question 35

What is the grain size in conglomerates?

Answer 35

at least 30% grains bigger than 2mm

Question 36

What is a monomict conglomerate?

Answer 36

stable conglomerates composed of a single clast type

Question 37

What is a polymict conglomerate?

Answer 37

a conglomerate that contains an assortment of many clasts types

Question 38

What is a petromict conglomerate?

Answer 38

Polymicts that are composed of unstable or metastable clasts

Question 39

What is monomict derived from?

Answer 39

Sedimentary rocks containing quartzite beds

Question 40

What is petromict derived from?

Answer 40

volcanic, metamorphic, or sedimentary rocks one type is dominant clast

Question 41

What is intraformational derived from?

Answer 41

clast sediments formed within a depositional basin flat pebble conglomerates

Question 42

What is the grain size in shales?

Answer 42

Fine sized grains between 1/16th-1/256mm that make up more than 50% of the rock?

Question 43

What is a shale?

Answer 43

A rock with silt size grains that has laminations?

Question 44

What is a mudrock?

Answer 44

a rock with silt size grains without laminations

Question 45

What is the composition of shales/mudrocks?

Answer 45

Clay minerals, free of quartz and feldspars

Question 46

what is a mudstone?

Answer 46

33-65% clay size constituents

Question 47

What is a mud shale?

Answer 47

33-65% with laminations

Question 48

What is a claystone?

Answer 48

66-100% clay grains

Question 49

What is a clay shale?

Answer 49

66-100% with laminations

Question 50

What is the diagenetic process of clastic rocks?

Answer 50

Uplict to burial and sedimentation