Brainscape's Knowledge GenomeTM

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


See full index

Geotechnics > Engineering geology lecture 1 > Flashcards

Engineering geology lecture 1 Flashcards

1
Q

What is the definition of a mineral?

A

Naturally ocuring inorganic substance which has a definite chemical composition and presents an ordered atomic arrangement

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

What is the definition of a rock?

A

An aggregate of one or more mineral, the nature and the properties of a rock are determined by the minerals in it and the manner in whcih the minerals are arranged relative to each other

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

What rock is chrystallised from molten magma?

A

Igneous

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

How are sedimentary rocks fromed?

A

From erosion on the Earth’s surface

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

How are metamorphic rocks formed?

A

They are altered by heat and/ or pressure

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

Which environment do Igneous rocks come from?

A

Underground, as lava flows

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

What rocks are formed in deposition basins, mainly sea?

A

Sedimentary

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

Where are metamorphic rocks found?

A

Mostly deep inside mountain chains

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

What type of rock is described as a mosaic of interlocking crystals?

A

Igenous and metamorphic

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

What is the texture of a sedimentary rock?

A

mostly granular and cemented

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

Wnat is the structure of an ingeous rock?

A

massive (structureless)

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

What is the structure of a sedimentary rock?

A

Layered, bedded, bedding planes present

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

What is the structure of a metamorphic rock?

A

Chrystal orientated

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

What type of rocks have uniform high strength?

A

Igneous

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

How strong are sedimentary rocks?

A

Variable low, planar weaknesses present

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

How strong are metamorphic rocks?

A

Highly variable

Can have planar weakness

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

What are some main types of Igneous rock?

A

Granite
Granodiorite
Basalt

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

What are some main types of Sedimentary rocks?

A

Sandstone
Limestone
Clay

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

What are some main types of metamorphic rocks?

A

Gneiss
Schist
Slate

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

What characteristics are helpful when dealing with minerals?

A
  1. Colour
  2. Lustre (appearance/ reflectance)
  3. Form (shape/ group/ clustering)
  4. Hardness (resistance to abrasion)
  5. cleavage (preferential split)
  6. Fracture (nature of broken surfaces - lack of cleavage)
  7. Tenacity (response upon sudden impact i.e. malleable vs brittle)
  8. specific gravity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the 2 different classifications of minerals?

A
  1. Silicate minerals

2. non - silicate minerals

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

What kind of mineral is olivine, and what colour is it?

A

Pale olive-green

Silicate mineral

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

What kind of mineral is pyroxene and what colour is it?

A 
Dark colour (black)
silicate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What kind of mineral is amphibole and what colour is it?

A 
Dark colours (various) 
silicate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What kind of mineral is Mica?

A

Slicate

It is various colours

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

What kind of mineral is Feldspar and what colour is it?

A

Pink/ white/ colourless

Silicate

27
Q

What kind of mineral and what colour is silica?

A

Colourless

silicate

28
Q

What is the mean feature of the mica group?

A

Readily splits into thin flakes

Transparent in a single sheet

29
Q

Why does the mica group split into thin flakes?

A

it has cleavage perfectly parallel to the basal plane

30
Q

What are two common micas?

A

Muscovite (colourless/ silvery)

Biotite (dark brown to black)

31
Q

What happens when mica weathers?

A

Metal ions are removed from the minerals

Results in soluble metal ions and clay minerals

32
Q

What are 2 common Feldspars?

A 
Alkali Feldspar (pink or white)
Plagioclase feldspar (white, colourless or grey)
33
Q

What reaction occurs when feldspar weathers?

A

Hydrolysis - a reaction between the minerals of water and the H+ and OH- ions present in water

Ksilica +(H+OH-) –> HSilicate + (K+OH-)

34
Q

What is formed during the weathering of feldspar?

A

Kaolinite

35
Q

Where do extrusive igeneos rocks come from?

A

erupting volcanoes

oozing fissures

36
Q

How are extrusive igneous rocks formed?

A

When magma exits and cools above the Earth’s surface

37
Q

Where do intrusive igneous rocks come from?

A

The Earth’s crust, only visible after the higher levels of rocks are eroded away

38
Q

WHow are intrusive igneous rocks formed?

A

From molten rock insed the earth, cool at the earths crust

39
Q

What is the range of silica content in igneous rock?

A

From 40-80%

40
Q

How much silica does a felsic rock have?

A

high amounts

41
Q

How much silica does a mafic rock have?

A

Low amounts

42
Q

What are the 2 main types of Extrusive igneous rocks?

A

Fissure eruptions

Central eruptions

43
Q

What are the characteristics of a fissure erupted igneous rock?

A

Low viscosity, far flowing basaltic lava

Produces fine-grained igneous rocks like plateau-basalt

44
Q

What are the defining characteristics of a central eruption?

A

Ejection of lava, gases and broken rock

45
Q

What is an example of a central erupted igneous rock?

A

Tuff - can be called a pyroclastic igneous rock

46
Q

What texture does an intrusive igneous rock have?

A

Equigranular

47
Q

What texture does and extrusive igneous rock have?

A

Aphantic texture

48
Q

What word describes chrystal of all the same size?

A

Equigranular

49
Q

What word describes crystals that are clearly larger than others?

A

inequigranular

50
Q

What word describes large crystals surrounded by much smaller crystals?

A

Porphyritic

51
Q

What facilitates the growth of larger and larger minerals?

A

The right temperature and pressure conditions for its continued growth

52
Q

Which word describes a crystal with a regular shape?

A

Euhedral

53
Q

What allows Euhedrals to form their natural shape?

A

They have had the space to grow

Anhedral minerals grow to fit in a space

Euhedral minerals form before Anhedral minerals

54
Q

What temperature do olivine and quartz chrystallise at?

A

Olivine: 1200 C
Quartz: 700 C

55
Q

How does susceptibility to chemical weathering relate to the melting point they chrystallise at?

A

The higher the chrystallisation temperature, the more suscpetible to chemical weathering

56
Q

What kind of rocks are produced by the surface processes of the rock cycle?

A

Sedimentary

57
Q

What are the 2 types of sedimentary rocks?

A
  • Clastic “standard” (exogenic)

- Non-clastic “others” (endogenic)

58
Q

What kind of sedimentary rocks have been deposited and either bedified or stratified horizontally?

A

Clastic

59
Q

What are the very important conditions in which sedimentary rocks are formed?

A

Depositional environment

The available settlements

60
Q

What sedimentary rock does mud turn into with pressure and temperature?

A

Shale

61
Q

What sedimentary rocks does sand with pressure and temperature turn into?

A

Sandstone

62
Q

What sedimentary rocks does gravel with pressure and temperature turn into?

A

Conglomerate

63
Q

What is the definition of shale?

A

Rocks formed from compact muds, finely laminated structure with a tendency to break along parallel side fragments.

Mudstones typically break into blocky pieces

64
Q

What is an example of a non-clastic sedimentary rock?

A

Limestone (carbonate rock)

Evaporties (salt rocks)

Geotechnics (12 decks)

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