Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Fall 2018 > Geology 101 Quiz 6 > Flashcards

Geology 101 Quiz 6 Flashcards

1
Q

sedimentary rocks form in one of two ways

A

(1) by accumulation and lithification of particles or (2) by precipitation from solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

in either case of formation, sedimentary rocks form by accumulating or precipitating what?

A

existing particles or ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

weathering

A

the process of breaking down rocks both physically and chemically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

physical weathering

A

refers to physical breakage of rocks and minerals. Smaller pieces retain the same chemical and mineral structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

chemical weathering

A

refers to the chemical alteration of minerals by either complete dissolution, or by reactions that partially dissolve a mineral and leave a new mineral phase in its place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

physical weathering: breaking rock down into smaller pieces can be done in two ways

A

fracturing and abrasion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

fracturing

A

creating a break to separate one piece into two or more pieces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

joints

A

fractures with no displacement on either side of the break

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

faults

A

fracture where the rock on one side of the break has moved relative to the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

abrasion

A

wearing away the surface of a rock by striking or scraping with other rock fragments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

causes of fracturing (large scale processes to smaller scale)

A
  1. tectonics
  2. uplift and erosion
  3. cooling
  4. undermining
  5. ice wedging (or frost wedging)
  6. roots
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

tectonics

A

fracturing causes by tectonic plates moving

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

uplift and erosion

A

as overlying rock is removed, the reduced pressure allows the exposed rock to expand - since expansion is always uneven, the rock fractures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

special cases of uplift and erosion can

A

produce layers of rock breaking away like layers on an onion (called exfoliation or spheroidal weathering)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

cooling

A

as newly solidified igneous rock cools, it contracts; contraction is always uneven, and fractures develop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

undermining

A

if erosion cuts away lower rock resulting in overhang, the rock will eventually fracture and fall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

example of undermining

A

the Old Man in the Mountain (New Hampshire) gone in 2003

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

ice wedging (or frost wedging)

A

water expands when it freezes and can exert an incredible force; if water fills a crack and freezes, the expanding ice can widen the crack or cause the rock to completely split

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

roots

A

small roots can grow into a small fracture; as the root grows, it can widen the fracture or split the rock open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

causes of abrasion (large scale processes to smaller scale)

A
  1. tectonic faulting
  2. glaciers
  3. landslides
  4. water carried rocks
  5. wind blown sand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

tectonic faulting

A

where two plates slide past each other, rock can be pulverized and smeared along the fault

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

glaciers

A

glaciers trap blocks of rock in the ice that grind over rocks beneath the glacier; this process can grind rock so fine it is referred to as rock/glacial flour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

landslides

A

as rocks fall, they strike other rocks and both break and abrade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

water carried rocks

A

water borne rocks strike other rocks and slowly abrade the surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

wind blown sand

A

in water, sand may travel around a rock without striking it due to the cushioning effect of the water; in air, the cushioning effect is reduced, and blowing sand strikes and abrades the surface - same principle as a sand blaster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

fracturing and abrasion can reduce a mineral down to a powder, but it will not produce

A

most of the clay minerals commonly found throughout this area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

chemical weathering is typically achieved by either

A

dissolution or oxidation reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

two ways dissolution can occur

A

congruent and incongruent dissolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

congruent dissolution

A

complete dissociation of the atoms in the molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

examples of congruent dissolution

A

halite: NaCl -> Na^+ + Cl^-
calcite: CaCO3 -> Ca^2+ + CO3^2-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

when a small crystal of halite or calcite is placed in water

A

it completely dissolves; no residue is left behind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

if a large mass of halite or calcite is placed in water

A

the minerals completely dissolve until the water cannot hold any more of the dissolved ions, then dissolution stops (the portion that did dissolve, however, dissolves completely with no residue left behind)

33
Q

incongruent dissolution

A

partial dissolution of a mineral resulting in a new mineral phase

34
Q

example of incongruent dissolution

A

orthoclase to kaolinite (clay) - some of the ions of orthoclase are dissolved, some are rearranged in the new mineral (kaolinite) and water has been incorporated into the new mineral

35
Q

? can enhance weather of some minerals

A

acid

36
Q

acid is

A

simply a hydrogen ion H+

37
Q

nature supplies its own acid by

A

dissolving carbon dioxide in water

CO2 + H20 -> H^+ + HCO3^-

38
Q

in most cases, if water is actually part of the reaction, added acid will

A

increase the rate of reaction

39
Q

sulfur and nitrogen emissions from burning fossil fuels (particularly coal) can

A

increase the acid content of rain (known as acid rain)

40
Q

ancient sculptures made of limestone or marble (both calcite) heave weather must faster due to

A

acid rain

41
Q

oxidation

A

alteration of a mineral by removing electrons, usually by oxygen

42
Q

if electrons are removed, the charge on an ion changes, which means

A

the chemical formula must be altered to achieve charge balance

43
Q

physical and chemical weathering ? each other

A

enhance

44
Q

chemical weathering weakens the rock, which results in

A

faster physical weathering

45
Q

common minerals that undergo incongruent dissolution and oxidation to produce clays & oxides

A

muscovite, K-feldspar, biotite, plagioclase, amphibole, pyroxene, olivine

46
Q

common minerals that undergo congruent dissolution and totally dissolve

A

quartz, calcite, halite

47
Q

weathering rates are increased by

A
  1. contact with water
  2. contact with air (CO2 and O2)
  3. higher temperature
48
Q

weathering is greatest in what kind of climates?

A

hot and humid

49
Q

solids also increase weathering by

A

retaining moisture and facilitating root action

50
Q

soil

A

weathered rock plus organic material (humus); typically layered

51
Q

the layers of soil are referred to as

A

horizons

52
Q

entisols

A

soils without layering

53
Q

vertisols

A

contain expandable clays and layers mix

54
Q

inceptisols

A

young soils, poorly formed layering and weathering

55
Q

aridosols

A

desert soils, saline or alkaline soils

56
Q

mollisols

A

calcium rich soils high in humus

57
Q

spodosols

A

light gray, leached A horizon, organic material carried to B horizon

58
Q

alfisols

A

acid soils with clay rich subsoils

59
Q

ultisols

A

more weathered alfisols

60
Q

oxisols

A

intensely weathered and leached soils

61
Q

histosols

A

wetland soils

62
Q

andisols

A

volcanic ash soils

63
Q

gelisols

A

permafrost soils

64
Q

A horizon

A

upper layer (zone of leaching); ranges from topsoil to bottom of root zone, generally rich in organic material (humus) rainwater dissolves minerals (leaching)

65
Q

B horizon

A

zone of deposition; little organic matter, dissolved minerals from A-horizon may precipitate (Fe and Al oxides, calcite), often contains weathered rock fragments

66
Q

C horizon

A

weathered rock

67
Q

soil layers are not always

A

alphabetical (e.g., R, H, E, O)

68
Q

dry climate’s effect on A horizon

A

thin, mostly unweathered

69
Q

dry climate’s effect on B horizon

A

caliche formation

70
Q

temperate climate’s effect on A horizon

A

thick, rich in humus, mildly weathered

71
Q

temperate climate’s effect on B horizon

A

minor precipitates

72
Q

tropic climate’s effect on A horizon

A

very little humus, highly leached

73
Q

tropic climate’s effect on B horizon

A

insoluble Fe and Al minerals that do not leach

74
Q

best quality soil climate & characteristics

A

temperate; rich in humus and not highly leached

75
Q

intermediate quality soil climate & characteristics

A

arid; not highly leached, but poor in humus

76
Q

poor quality soil climate & characteristics

A

tropical; highly leached

77
Q

how can tropical soils be poor if they support lush jungles

A

all the nutrients are in the plants, not the soil

78
Q

why do subsistence farmers only grow crops for a few years before the crops start to fail and they have to clear a new plot of land?

A

the soil is poor and only the dying plants are the source of nutrients for growing plants

Fall 2018 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions