Geology 101 Part 2

Front 1

what is melt below the earths surface

Back 1

magma

Front 2

rock formed by magma

Back 2

intrusive igneous rock

Front 3

rock formed by lava

Back 3

extrusive igneous rock

Front 4

decompression

Back 4

melting as a result of decrease in pressure

Front 5

addition of volatiles

Back 5

flux melting

Front 6

how hot are mantle-derived magmas?

Back 6

over 1,100 celcius

Front 7

at what temperature do rocks of the crust melt?

Back 7

about 650 to 850 celcius

Front 8

what is magma made of?

Back 8

silicon and oxygen/silicon-oxygen tetrahedron. also Al< Ca, Na, K, Fe, and Mg

Front 9

felsic magma

Back 9

high silica, feldspar/quartz

Front 10

intermediate magma

Back 10

52-66% silica, composition between felsic and mafic

Front 11

mafic magma

Back 11

45 to 52% silica, produces rock containing abundant mafic minerals

Front 12

ultramafic magma

Back 12

low silica content

Front 13

viscosity

Back 13

resistance to flow, reflects its silica content

Front 14

viscosity for different types of magma?

Back 14

felsic magma - high viscosity (sticker and flow less easily) than mafic magmas and also makes them less dense

Front 15

fractional crystallization

Back 15

magma changes composition as it cools because formation and sinking of crystals preferentially remove certain atoms from the magma

Front 16

can mafic magma evolve into a felsic magma?

Back 16

yes through fractional crystallization

Front 17

dike

Back 17

place where tabular intrusions cut across rock that does not have layering, a nearly vertical wall-like tabular intrusion

Front 18

sill

Back 18

nearly horizontal, tabletop-shaped tabular intrusion

Front 19

plutons

Back 19

irregular or blob-shaped intrusions that range in size from tens of meters across to tens of kms across

Front 20

what does glassy texture tell us?

Back 20

cooled quickly

Front 21

hot-spot volcanoes

Back 21

isolated volcanoes that are independent of plate-boundary interactions

Front 22

sediment

Back 22

consists of loose fragments of rocks or minerals broken off bedrock, mineral crystals that precipitate directly out of water, and shells (formed when organisms extract ions from water)

Front 23

sedimentary rock

Back 23

rock that forms at or near the surface of the earth by the precipitation of minerals from water solutions, by the growth of skeletal material in organisms, or by the cementing together of shell fragments, or of loose grains derived from preexisting rocks

Front 24

weathering

Back 24

processes that break up and corrode solid rock transforming it into sediment.

Front 25

physical weathering

Back 25

mechanical weathering, breaks rocks - jointing, frost wedging, root wedging, salt wedging, thermal expansion, animal attack

Front 26

chemical weathering

Back 26

refers to chemical reactions that alter or destroy minerals when a rock comes in contact with water solutions or air

Front 27

more cracks in a rock =

Back 27

more surface area

Front 28

transported soil includes those formed from deposits left by..

Back 28

rivers, glaciers, or wind

Front 29

sandstone

Back 29

example of clastic sedimentary rock created from solid grains stuck together to form a solid mass

Front 30

erosion

Back 30

combination of processes that separate rock or regolith from its substrate and carry it away

Front 31

transportation

Back 31

moving air, water, or ice transports sediment from one location to another

Front 32

deposition

Back 32

the process by which sediment settles out of the transporting medium

Front 33

lithification

Back 33

the transformation of loose sediment into solid rock

Front 34

clast size

Back 34

diameter of clasts making upa rock - coarsest to finest = boulder, cobble, pebble, sand, silt, and clay

Front 35

sorting of clasts

Back 35

indicates the degree to which the clasts in a rock are all the same size or include a variety of sizes

Front 36

breccia

Back 36

angular fragments with sharp edges

Front 37

conglomerate

Back 37

rounded clasts

Front 38

ripples

Back 38

relatively small, elongated ridges that form on a bed surface at right angles to the direction of the current flow

Front 39

graded bed

Back 39

layer of sediment at which grain size varies from coarse at the bottom to fine at the top

Front 40

metamorphism

Back 40

the process of forming metamorphic rock, new minerals may grow at the expense of old ones, and/or the shape, size, and arrangement of grains in the rock may change

Front 41

protolith

Back 41

parent rock - subjected to heat, pressure, differential stress, and or hydrothermal fluids

Front 42

metamorphism is a ____ process

Back 42

solid-state

Front 43

metamorphic texture

Back 43

the grains in the rock have grown in place and interlock

Front 44

differential stress

Back 44

the push or pull in one direction differs in magnitude from the push or pull in another direction

Front 45

normal stress

Back 45

pushes or pulls perpendicular to the surface, push = compression, pull = tension

Front 46

shear stress

Back 46

moves one part of the material sideways relative to the other

Front 47

types of metamorphic rocks

Back 47

foliated/non-foliated

Front 48

foliated

Back 48

phyllite, slate, schist, gneiss - they have layers

Front 49

non-foliated

Back 49

hornfels, amphibolite, quartzite, marble

Front 50

thermal metamorphism/contact metamorphism

Back 50

caused by igneous intrusion , develops adjacent to to an intrusion

Front 51

what drives rock cycle

Back 51

internal heat, gravitational field

Front 52

basaltic lava flows

Back 52

low viscosity

Front 53

pahoehoe

Back 53

flows with warm, pasty surfaces wrinkle into smooth, glassy, rope-ike ridges

Front 54

a'a'

Back 54

if the surface layer of the lava freezes and then breaks up due to the continued movement of lava underneath, it becomes a jumble of sharp, angular fragments

Front 55

rhyoltic lava flows

Back 55

most viscous of all lavalas, most silicic and the coolest

Front 56

caldera

Back 56

formed after major eruptions, the center of the volcano may collapse into the large partly drained magma chamber below

Front 57

greatest number of fatalities result from...?

Back 57

pyroclastic flows

Front 58

pyroclastic flows

Back 58

race down the flanks of a volcano at speeds of 100 to 300 km per hour, cloud can be so hot and poisonous that it can result in instant death and the force can flatten buildings and forests

Front 59

active volcanoes

Back 59

are erupting, have erupted recently, or are likely to erupt soon

Front 60

dormant volcanoes

Back 60

have not erupted for 10,000 years but do have potential to erupt again

Front 61

extinct volcanoes

Back 61

active in the past but have shut off entirely and will never erupt again

Front 62

hypocenter

Back 62

focus, the place in the earth where rock ruptures and slips or the place where the explosion occurs

Front 63

epicenter

Back 63

lies directly above the hypocenter

Front 64

body waves

Back 64

pass through the interior of the earth

Front 65

surface waves

Back 65

travel along the earth's surface

Front 66

P-waves

Back 66

primary, compressional body waves

Front 67

S-waves

Back 67

secondary, shear body waves

Front 68

R-waves

Back 68

Rayleigh, surface waves that cause the ground to ripple up and down

Front 69

L-waves

Back 69

Love, surface waves that cause the ground to ripple back and forth in a snake-like movement

Front 70

seismograph

Back 70

systematically records the ground motion from an earthquake happening anywhere one arth

Front 71

seismogram

Back 71

the waves traced by a pen on a seismograph provide a record of the earthquake

Front 72

travel-time curve

Back 72

plots the time since the earthquake began on the vertical axis and the distance to the epicenter on the horizontal axis

Front 73

mercalli intensity scale

Back 73

defines intensity of an earthquake by the amount of damage it causes

Front 74

magnitude

Back 74

number than indicates the earthquake's relative size as determined by measuring the maximum amplitude of ground motion recorded by a seismograph at a given distance from the epicenter

Front 75

Richter scale

Back 75

scale used to define and measure earthquake magnitude

Front 76

P-waves

Back 76

primary, compressional body waves

Front 77

S-waves

Back 77

secondary, shear body waves

Front 78

R-waves

Back 78

Rayleigh, surface waves that cause the ground to ripple up and down

Front 79

L-waves

Back 79

Love, surface waves that cause the ground to ripple back and forth in a snake-like movement

Front 80

seismograph

Back 80

systematically records the ground motion from an earthquake happening anywhere one arth

Front 81

seismogram

Back 81

the waves traced by a pen on a seismograph provide a record of the earthquake

Front 82

travel-time curve

Back 82

plots the time since the earthquake began on the vertical axis and the distance to the epicenter on the horizontal axis

Front 83

mercalli intensity scale

Back 83

defines intensity of an earthquake by the amount of damage it causes

Front 84

magnitude

Back 84

number than indicates the earthquake's relative size as determined by measuring the maximum amplitude of ground motion recorded by a seismograph at a given distance from the epicenter

Front 85

Richter scale

Back 85

scale used to define and measure earthquake magnitude

Front 86

Wadati-Benioff zone

Back 86

downgoing slab sinks into the mantle

Front 87

liquefaction

Back 87

the abrupt loss of strength of a wet sediment in response to ground shaking

Front 88

why do most earthquakes happen

Back 88

when rock breaks during faulting

Front 89

different types of faults

Back 89

normal, reverse, thrust, and strike-slip faults

Front 90

stuff about the richter scale

Back 90

a magnitude 8 earthquake yields about 10 times as much ground motion as a magnitude 7 earthquake and releases about 32 times as much energy

Front 91

where do most earthquakes occur?

Back 91

in seismic belts, or zones, of which the majority lie along plate boundaries

Front 92

earthquakes don't occur where?

Back 92

in the continent crust where rocks become ductile