Brainscape's Knowledge GenomeTM

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


See full index

Geology AS > AS Sedimentary Rocks > Flashcards

AS Sedimentary Rocks Flashcards

1
Q

Weathering

A

the in situ chemical alteration and mechanical and biological breakdown of rocks by exposure to the atmosphere, water and organic matter.

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

Carbonation

A

the reaction between carbonic acid and minerals.

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

Hydrolysis

A

is the reaction between minerals and water, causing the minerals to decompose.

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

Exfoliation

A

occurs when sheets of rock split off due to differential expansion and contraction of minerals, during diurnal heating and cooling.

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

Frost shattering

A

caused by the expansion of freezing water in fractures, which forces rocks apart.

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

Pressure release

A

caused by the expansion and fracturing of rock due to removal of overlying rock.

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

Root action

A

causes the mechanical and chemical weathering of rocks by the wedging action of plant roots.

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

Burrowing

A

by invertebrate and vertebrate animals mixes and brings rock and soil particles to the surface. This facilitates weathering at greater depth, by providing access for atmospheric gases and water.

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

Erosion

A

the wearing away of the land surface and removal of sediment by means of transport.

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

Abrasion

A

the wearing away of the Earth’s surface by the action of wind, water or ice dragging sediment over or hurling it at a surface.

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

Attrition

A

the wearing down of sedimentary grains due to collisions with other grains during transport.

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

Mineralogical maturity

A

a measure of the extent to which minerals have been destroyed by weathering and attrition.

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

Solution

A

the transport of ions dissolved in water, particularly K, Ca and Na.

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

Traction

A

the transport of material by rolling and sliding along a surface.

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

Saltation

A

the transport of material by bouncing.

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

Suspension

A

the transport of material in water or air, without it touching the Earth’s surface.

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

Roundness

A

defines the relationship of the outline of a grain to a circle. A grain with few sharp corners has a high degree of roundness.

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

Shape

A

defines the relationship of a grain to a sphere, rod, disc or blade.

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

Phi scale

A

expresses grain size on a logarithmic scale. Phi values increase arithmetically as the grain size decreases geometrically.

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

Textural maturity

A

a measure of the extent to which a sediment is well sorted and well rounded.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Sorting

A

the degree to which particles are the same size.

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

Mechanically formed

A

sedimentary rocks result from the processes of erosion, transport and deposition of clasts.

23
Q

Siliciclastic rocks

A

form from sediments composed of silicate minerals and rock fragments.

24
Q

Matrix

A

the background material of small grains in which larger grains occur.

25
Q

Clay minerals

A

a group of sub-microscopic platy aluminium silicates related to mica.

26
Q

Plasticity

A

the ability of a material to permanently change shape without fracturing.

27
Q

Fissile

A

refers to the tendency of a rock to split into thin layers.

28
Q

Ooliths

A

spherical grains showing concentric banding of carbonate material. These are less than 2 mm in diameter, if larger they are called pisoliths.

29
Q

Micrite

A

a microcrystalline calcite, a depositional matrix of lime mud.

30
Q

Sparite

A

a coarse grained (>0.01 mm) crystalline calcite cement, formed after deposition.

31
Q

Cement

A

the minerals precipitated between grains in sedimentary rocks binding them together.

32
Q

Pellets

A

are carbonate material excreted by animals. They lack concentric structures and are normally 0.04 to 0.08mm diameter.

33
Q

Diagenesis

A

all the changes that take place in sediments at low temperature and pressure, at or near to the Earth’s surface.

34
Q

Lithification

A

the process of changing unconsolidated sediment into rock.

35
Q

Pressure dissolution

A

(sometimes called pressure solution) occurs where minerals dissolve as the result of applied pressure. Because pressure dissolution leads to a reduction of volume of the rock in which it occurs, it is also called chemical compaction.

36
Q

Porosity

A

the volume occupied by spaces in between sedimentary grains. A reduction in porosity squeezes fluids from pore spaces.

37
Q

Peat

A

partly decomposed plant remains with high water content.

38
Q

Coal

A

a carbon-rich rock formed from fossil plant remains.

39
Q

Permeability

A

is the ability of a rock to allow fluids such as water to pass through it.

40
Q

Breccia

A

A coarse, angular grained, poorly sorted siliciclastic sedimentary rock

41
Q

Conglomerate

A

A coarse, rounded grained, poorly sorted sedimentary rock

42
Q

Orthoquartzite

A

A coarse, well sorted, well-rounded sandstone, quartz grains with a quartz cement, >90% quartz

43
Q

desert sandstone

A

A coarse, well sorted, well rounded sandstone. Red in colour due to iron present around the grains, often an iron oxide cement

44
Q

Arkose

A

Medium to coarse grained sandstone that contains over 25% feldspar. Sub angular to sub rounded.

45
Q

Greywacke

A

Poorly sorted, angular sandstone, dark in colour. Contains some feldspar and clay in addition to quartz

46
Q

Clay

A

A fine grained, plastic siliciclastic rock, contains mostly clay minerals.

47
Q

Mudstone

A

A fine grained siliciclastic rock that contains clay, mica and quartz. No layers, not plastic.

48
Q

Shale

A

A fine grained, dark, siliciclastic rock that shows alignment of flat platy clay minerals, also contains some mica and quartz.

49
Q

Oolitic limestone

A

A limestone consisting of calcium carbonate ooliths, approximately 1mm in diameter, form in tropical seas. Held together by calcite cement

50
Q

Fossiliferous limestone

A

Limestone made up of a large proportion of fossils or fossil fragments held together with a calcite cement

51
Q

Chalk

A

A limestone composed of coccoliths, the calcareous skeletons of single celled algae

52
Q

Folk classification

A

A limestone classification based on the type of grains present and the cement. E.g. oo, intra, bio, pel, micrite, sparite

53
Q

Dunham classification

A

A limestone classification system based on texture and mud content:
<10% grains - Mudstone,
>10% grains - Wackstone.
Grains and mud - Packstone,
Grains, lacks mud - Grainstone

Geology AS (10 decks)

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