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Flashcards in Test One Key Terms Deck (85):
1

Age of Earth

4.6 billion years old

2

Asthenosphere

the soft, weak layer below the lithosphere

3

Craton

the stable interior of the continents

4

Density

mass per unit volume

5

Differentiation

process by which Earth came to have its present interior structure

6

Earth's spheres

Hydrosphere, Atmosphere, Geosphere, Biosphere

7

Geologic Hazard

natural processes that adversely affect people

8

hypothesis

a tentative or untested explanation

9

Lithosphere

the rigid outer layer of Earth that consists of the crust and the upper mantle

10

Layers of Earth

Crust
Mantle
Core

11

Natural Disaster

flood, earthquake, hurricane, tornado, etc. causes damage and or loss of life

12

Plate tectonics

Continental plates include things like Mountains
Ocean floors include things like ocean ridges

13

Shield

expansive, flat regions of deformed crystalline rocks in the cratons

14

Theory

a well-tested and widely accepted view that the scientific community agrees best explains certain observable facts

15

Uniformitarianism

the physical, chemical, and biologic laws that operate today have operated throughout the geologic past

16

Continental drift

a supercontinent once existed and began to break apart about 200 million years ago

17

Convection currents

in the mantle where warm buoyant rocks rise and cool, dense rocks sink, is the underlying driving force of plate tectonics
major force for transporting heat away from the interior of Earth

18

Convergent boundaries

destructive margins
plates move together

19

Divergent boundaries

constructive margins
plates move apart

20

Magnetic reversal

the north pole becomes the south pole and the south becomes the north pole

21

Mantle plume

cylindrically shaped upwelling of hot rock

22

Mid-ocean ridge

along well developed divergent plate boundaries and the seafloor is elevated

23

Paleomagnetism

magnetite is the frozen in position and indicates the and indicates the position of the north pole at the time of rock solidification

24

Pangea

supercontinent that consistedof all Earth's landmasses
began breaking apart about 200 million ago

25

Plate tectonics

The lithosphere is broken into two dozen smaller sections called lithospheric plates that are in constant motion

26

Rift valley

along the crest of the ridge is a canynon-like feature

27

rifting

elongated depression will develop within the region of the divergence

28

Seafloor spreading

the mechanism that operates along the ridge to create new ocean floor

29

Slab pull

The subduction of cold oceanic lithosphere

30

Subduction zone

the leading edge of one plate is bent downward as it slides beneath the other

31

Transform boundaries

conservative margins
plates grind past each other without the production or destruction of lithosphere

32

Trench

produced at subduction zones

33

Volcanic arc

when volcanoes emerge as islands
when oceanic-continental convergence, partial melting initiates volcanic activity

34

Ion

positively and negatively charged atoms

35

Isotope

same number of protons but different numbers of neutrons

36

Lithology

study of rocks

37

Mineral

Natural occurring
Inorganic
solid substance
crystalline structure
definite chemical composition

38

Mineralogy

study of minerals

39

Mohs hardness scale

tests resistance to abrasion or scratching

40

Oxide

contains at least one oxygen atom and one other element in chemical formula

41

Periodic Table

Elements organized so that those with similar properties line up

42

Silicate

minerals that are the most common type of minerals
make up 90% of the earths crust
silicon and oxygen make up the building blocks

43

Trace elements

elements that occur in such small concentrations they do not change the essence of a material

44

Basaltic

Mafic

45

Batholith

large intrusive body
expansive

46

Bowen's Reaction Series

Minerals crystallize in a systematic fashion based on their melting points
The composition of the liquid portion of the magma continually changes

47

Cooling rate

slow rate = fewer but larger crystals
fast rate = many but small crystals

48

Dike

tabular, discordant pluton
conduits to transport magma

49

Extrusive

Volcanic
solidification of lava or volcanic debris on surface

50

Felsic

light colors
made of quartz and feldspar
high silica content
makes up huge part of continental crust

51

Geothermal gradient

temperatures in the upper crust increase about 25 C per kilometer

52

Granitic

Felsic

53

Igneous

forms as molten rock cools and solidifies

54

Intrusive

plutonic
magma that crystallizes at depth (underground)

55

Laccolith

forcibly injected between sedimentary strata
Causes the overlying strata to arch upward

56

Lava

magma at the surface

57

Mafic

Dark colored
iron and magnesium
higher density
make up ocean floor and volcanic islands

58

Sill

concordant pluton
tend to accumulate magma and increase in thickness

59

Texture

overall appearance of a rock based on the size, shape, and arrangement of mineral grains

60

Vesicular

rocks contain voids left by gas bubbles in the lava
common feature of extrusive igneous rock

61

Volatile

dissolved gases in the melt that vaporize at surface pressure

62

Calderea

volcanic crater that has a diameter of bigger than a kilometer and is produced by a collapse following a massive eruption

63

Crater

a funnel-shaped depression at the summit of most volcanic cones (small)

64

Lava Flow

mostly basaltic
Aa and Pahoehoe

65

Pyroclastic

pulverized rock and lava fragments

66

Quiescent

involves fluid basaltic lavas
Quiet eruptions that last a long time

67

Ring of Fire

Stratovolcanoes that are located adjacent to the Pacific ocean

68

Scoria

Reddish-brown porous rock from frothy basaltic and andesitic lava

69

Types of Volcanoes

Shield Volcanoes
Cinder Cones
Composite

70

Vesicles

holes in rocks left from dissolved gases

71

viscosity

resistance to flow
controlled by: Temperature, Composition, and Dissolved gases

72

Agents of chemical weathering

The most important is water

73

Agents of erosion

n

74

Carbonic acid

created when carbon dioxide dissolves in raindrops
Calcite is easily attacked by weakly acidic solutions

75

Humus

remains of animals that are converted into organic component of soil

76

Hydrolysis

reaction of any substance with water

77

Interface

n

78

Regolith

Earth's land surface is covered by a layer of rock and mineral fragments

79

Residual soil

soil that is in its original location

80

Sheeting

large masses of igneous rocks are exposed by erosion and concentric slabs break loose

81

Soil

combination of mineral and organic matter, water, and air and supports plant growth

82

Spheroidal

Weathering attacks edges from two sides and corners from three sides
Sharp edges become rounded

83

Talus

n

84

Transported soil

soil that has been moved from its original place

85

Types of weathering

Frost wedging
Salt crystal growth
Sheeting/Unloading
Biological activity