Brainscape's Knowledge GenomeTM

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


See full index

EAS 201 > Sedimentary Rocks > Flashcards

Sedimentary Rocks Flashcards

1
Q

____% of the land being sedimentary rocks

A

75%

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

Deposition or sedimentation occurs when

A

particles settle out or dissolved minerals precipitate

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

Burial occurs when

A

layers of sediment accumulate and compact previous layers

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

As a river carrying sediments enters the ocean, the coarser material (sand) is deposited ___

A

first

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

As a river carrying sediments enters the ocean, the finer material (silts and clays) is deposited ___

A

last (into deeper waters)

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

Clastic sedimentary rocks

A

products of the mechanical weathering of pre-existing rocks and are transported by gravity, water, ice or wind to accumulate as sediments in streams, lakes, oceans, soils or deserts

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

Chemical sedimentary rocks

A

do not form from themechanical break-up and transport of grains. Instead, they derive from the precipitation of minerals from supersaturated solutions

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

Examples of chemical sedimentary rocks

A

limestone (composed of calcite)
chert (composed of silica)
iron formations (composed of Fe oxides)
evaporites (gypsum and halite)

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

Biological sedimentary rocks

A

formed biologically from the shells of plankton

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

Examples of biological sedimentary rocks

A

diatoms and foraminifera

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

Sorting

A

the tendency for variations in current velocity to segregate sediments according to size (larger sand particles being deposited first)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Well-sorted sediments have been subject to ____ water or wind action

A

prolonged ( a lot)

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

Poorly-sorted sediments are either ____ from their source or deposited by ____

A

not far from their source (not far removed)

glaciers

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

The more round sand is, the ____ it has been transported

A

longer

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

The longer the transport process the more ____ the particles are subject to, making the rocks ____ and ____

A

abrasion, smaller, rounder

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

Sedimentary structures

A

sediment is deposited in horizontal layers called beds. in a sequence called strata. The sediment sinks and becomes thicker, with the oldest sediment at the bottom

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

Cross bedding

A

Changing the orientation of grains, consisting of bedding material deposited by wind or water and inclined at angles

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

Areas where cross-bedding occurs

A

steeper slopes of sand dunes and sandbars in rivers under the sea

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

Ripples

A

very small dunes of sand or silt whose long dimensions are at right angles to the wave direction

20
Q

Graded bedding is deposited by

A

dense muddy turbidity currents

21
Q

each layer in a graded bed progress from ___ grained to ___ grains

A

fine

coarse

22
Q

turbidites

A

accumulations of many fine grained-beds

23
Q

Bioturbated Structures

A

Bedding in sediments that are broken down due to the burrowing activity of animals (can be seen as cylindrical tubes the represent burros excavated by worms, clams, shrimp, etc).

24
Q

Process of forming sediment

A

sediments are buried, compacted, and lithified at earth’s crust

25
Q

Process of diagenesis

A

changing sediment into sedimentary rocks:
compaction by burial which squeezes out water, cementation (precipitation or addition of new minerals) causes the sediment particles to be segmented, and the cement becomes lithified (turned into a rock)

26
Q

Peak oil generation

A

100 degrees Celcius and 2750 m depth

27
Q

Peak gas generation

A

150 degrees Celcius and 4100 m depth

28
Q

Maturation

A

the process of turning the organic components in shale into oil and gas due to increasing temperatures

29
Q

Classifications of sedimentary rock

A

The coarse-grained, medium-grained, fine-grained, ad even finer

30
Q

Examples of coarse-grained sediment

A

gravel, boulder, cobble, and pebble

31
Q

Example of coarse-grained sedimentary rock

A

conglomerate

32
Q

examples of medium-grained sediment

A

sand

33
Q

Examples of medium-grained rocks

A

sandstone

34
Q

examples of fine-grained sediments

A

mud, silt

35
Q

Exmaple of fine-grained sedimentary rock

A

siltstone

36
Q

Example of finer sediment

A

clay

37
Q

Example of finer sedimentary rock

A

mudstone, shale, claystone

38
Q

The particle size of coarse grains

A

larger than 2 mm

39
Q

The particle size of medium-grains

A

2-0.062 mm

40
Q

Particle size of fine-grains

A

0.062-0.00393 mm

41
Q

Classifications of biological sediment

A

Sand and mud, siliceous sediment, peet (organic matter)

42
Q

Classifications of chemical sediment

A

formed by diagenesis, iron oxide sediment, evaporite sediment

43
Q

Carbonate platform process

A
  1. Reefs made of warm, shallow seas cause calcium to be precipitated by organisms
  2. Carbonate forms quickly in areas where there is a lot of organism growth (shallow)
  3. Sedimentation is slower in low light/deep areas
  4. rising sea level rises causes organisms to grow towards the sun (again increasing sedimentation)
  5. this results in a carbonate platform with steep sides falling away to the open ocean
44
Q

Chemical composition of seawater

A

Na+, Cl-, SO4(2-), Mg2+, Ca2+, HCO3(1-)

45
Q

Seawater evaporating causes the ____ of an ordered sequence of minerals of increasing ____.

A

precipitation, solubilities

46
Q

Order of precipitation in the ocean by solubilities

A

Limestone - CaCO3 (aragonite or calcite) at 40-60%, gypsum - CaSO4 (130-160%), Halite - NaCl (340-360%), Potash (bittern Salts - KCl) at 90x concentration.

47
Q

Banded iron formation

A

Precipitated iron and silica from ancient ocean showing the ancient ocean was primarily composed of iron and silica.

EAS 201 (12 decks)

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