Geology Test 2

Front 1

Rocks are relevant because?

Back 1

•Furthers our understanding of howto live on our planet and important information on natural resources (coal,hydrocarbons, nuclear, groundwater, surface waters)

Front 2

Definition of a mineral?

Back 2

•Naturally occurring,•homogeneous solid,•inorganically formed,•definite chemical composition, andordered atomic arrangement

Front 3

Rock include what kind of sediment material?

Back 3

Uncomplicated and unconsolidated

Front 4

What are the three major rock types?

Back 4

•Igneous•Sedimentary•Metamorphic

Front 5

Igneous rocks turn into_____ because of weathering

Back 5

Sediments

Front 6

Metamorphic rocks can turn into?

Back 6

Sediments or magma

Front 7

Texture of igneous rocks

Back 7

Interlocking crystals

Front 8

What can reveal the origin of an igneous rock?

Back 8

Crystal size and composition

Front 9

Dark colored rocks such as olivine basalt and peridotite have _________ silica saturation

Back 9

Low

Front 10

Quartz has _______ saturation

Back 10

Low silica Saturation

Front 11

What is the Chemical composition of fine grained Andesite?

Back 11

Andesitic

Front 12

Granite is ______ grained

Back 12

Coarse

Front 13

Comatose comes from what chemical composition?

Back 13

Ultramafic

Front 14

Which has higher silica content Quartz or Pyroxene?

Back 14

Quartz

Front 15

What composition has the highest % by volume?

Back 15

Granite

Front 16

At what temperature does Muscovite melt?

Back 16

About 700 C

Front 17

Biotite Mica comes from ____Due to cooling

Back 17

Amphibole, Pyroxene Olivine

Front 18

Quartz comes from

Back 18

Muscovite Mica and Potassium Feldspar

Front 19

Granite and Rhyolite are composed of?

Back 19

quartz, feldspars, and micas

Front 20

What kind of intrusive rock •Magmacools slowly•Crystalshave lots of time to grow•Rockmade up of coarse-grained crystals

Back 20

Granite

Front 21

Rhyolite is an Extrusive rock that

Back 21

•Magmacools rapidly•Crystalsdon’t have much time to grow•Rockmade up of fine-grained crystals

Front 22

What rocks are so fine grained that their mineralcrystals are not detectible by the unaided eye?

Back 22

Aphanitic

Front 23

Phaneritic are

Back 23

•mineralcrystals (matrix) are large enough to be viewed with the unaided eye.

Front 24

largegrained crystals (phenocrysts) in a fine grained matrix?

Back 24

Porphyry

Front 25

What are arethe largest forms of plutons, covering at least 100 km2?

Back 25

Batholiths

Front 26

Sills run_______ to Dikes

Back 26

Parallel Dikes are vertical

Front 27

Lava flows make

Back 27

Ashfalls and pyroclasts

Front 28

The weathered dome, standing above thesurrounding plain is known to geologists as

Back 28

monadnock.

Front 29

How old is the large igneous batholith, called the TownMountain Granite ofmiddle Precambrian?

Back 29

1.082 billion years old ±6 million years

Front 30

What is the material that intruded into earliermetamorphic schist

Back 30

Packsaddle Schist

Front 31

How is intrusive granite of the rock mass, orpluton exposed?

Back 31

Erosion

Front 32

Lavas are

Back 32

Basaltic, Andesitic, Rhyolitic

Front 33

_______ is of •low viscosity, flows readily and fast;simple silicates

Back 33

Blasaltic

Front 34

Rhyolitic lava is

Back 34

•more complex silicate (felsic) minerals;Yellowstone area magma

Front 35

What kind of intermediate silica content is sticky?

Back 35

Andesitic lava

Front 36

What kind of Pyroclastics, makes ash and bombs; makes tuffs and breccias

Back 36

ejecta lava

Front 37

Flows – hot expanding gas lifts __________

Back 37

•density flow of ejecta

Front 38

What kind of lava is ropy?

Back 38

Pahoehoe

Front 39

____ is like peanut butter and •Haslost gases so is more viscous•Occursfarther downhill from eruption vent

Back 39

Aa ( blocky)

Front 40

What lava type is of •Highlyfluid lava spreads in sheets and thin skin cools at surface•Fromnear eruption vent•Thinkhoney

Back 40

Pahoehoe

Front 41

WhereDo Igneous Rocks Form?

Back 41

•Plate Margins, •Large Igneous Provinces (LIPs), •Intraplate Volcanics (Hot Spots)

Front 42

A Fissure Eruptions ia an ________ Bundary

Back 42

Divergent

Front 43

What is an example of an Convergent Boundary?

Back 43

Volcanic Mountains

Front 44

Where are there a lot of active volcanoes?

Back 44

On the pacific plate

Front 45

Magma comes from

Back 45

Melted lithosphere

Front 46

Crystalssettle out of the magma, forming the

Back 46

peridotite layer.

Front 47

Differentialmelting enriches

Back 47

•the magma in silica and iron

Front 48

Magma

Back 48

•becomes basalt

Front 49

Magma leaves behind what after it becomes basalt?

Back 49

•Leaves behind massive gabbro

Front 50

The ______ layer metamorphosesby contact with the magma.

Back 50

Gabbro

Front 51

A ______ includes •Highlyfluid basalt•Lavaflows readily away from vent •Formswidespread layers rather than mountains

Back 51

Fissure erruption

Front 52

Volcanic IslandArc (Ocean-Ocean)Magmasource is?

Back 52

Oceancrust and sediments

Front 53

What kind of volcano has magmasource: mix of oceanic & continent crust and sediments

Back 53

Continent-Ocean

Front 54

Magma of intermediate composition is erupted to form

Back 54

Arc volcanoes

Front 55

Moltensediments combinewith ____ to make arc volcanoes

Back 55

lithosphericmagma

Front 56

An oceanic trench goes all the way to _______ to melt and become an island arc?

Back 56

Asthenosphere

Front 57

Fluid-Induced Melting is?

Back 57

when an oceanic crust goes to the asthenosphere and melts and releases the water causing the sediments to melt at lower temperatures

Front 58

LIPs(Large Igneous Provinces) are mainly?

Back 58

•Mainly “mafic” or basaltic lavas•Continental “flood” basalts•Ocean basin

Front 59

What event •at end of Permian Period (~225 mya)might have been involved in mass extinctions

Back 59

Siberian event

Front 60

•1 LIP event can erupt as much lavaas the entire ocean ridge system’s annual output TRUE OR FALSE

Back 60

True

Front 61

A “MantlePlume” Generatesmuch greater volume of ______ thana simple Hawaiian Island-type “hot spot”

Back 61

Basalt

Front 62

From where does the Plume Head in a volcano Hot Spot come from

Back 62

Outer core

Front 63

How can a hot spot create a chain of volcanoes?

Back 63

after the lithosphere is melted from the magma it moves out of the way of the magma creating a chain of extinct volcanoes.

Front 64

Rocks traveling through •narrow cylindrical jetMelt to magma because?

Back 64

Of pressure drop

Front 65

what is an •Aseismic

Back 65

•Inactive volcanoes along ridge withactive volcano at end

Front 66

What hot spot volcano is 4200m above SL and another 6000 m tosea floor-Base diameter of 120 km and where is it located?

Back 66

MaunaLoaHawaii

Front 67

_______ LeavesTrail of Old Extinct Volcanoes over Mantle “Hot Spot”

Back 67

Plate motion

Front 68

The yellowstone volcanism created ____ by ongoing volcanic activity

Back 68

Calderas as well as ―Geysers, boiling springs, uplift,earthquakes

Front 69

What are the three lava types and their characteristics

Back 69

•Basaltic – low viscosity, flows readily and fast;simple silicates (think honey)•

•Andesitic – intermediate silica content; sticky;can plug up volcanoes creating explosion hazard (think peanut butter)•

•Rhyolitic – more complex silicate (felsic)minerals; Yellowstone area magma

Front 70

Basaltic eruptions come from____ by accumulation of

Back 70

Shield volcanoes and have –Fluidbasalt – gentle sloped shape

Front 71

What has a ropy surface form?

Back 71

Pahoehoe

Front 72

What is Low Si magma is less viscous and morefluid than high Si magma

Back 72

Basalt from a shield volcano

Front 73

What dimensions can a Shield volcano have?

Back 73

60x10 km (HUGE)

Front 74

Hot spot volcanoes are huge

Back 74

that is all

Front 75

what are the three different basaltic eruptions and what are their characteristics?

Back 75

•Fissureeruptions – lowviscosity lava exuding from cracks•

•Floodbasalt –very large, rapid, fissure eruption•

•Lava(basalt) plateau – many cubic kilometers sized event

Front 76

•CinderCones come from?

Back 76

–Frompyroclastic fragments–Oftensteep, small, symmetrical–Mayfrom abruptly

Front 77

What kind of volcano is formed from deposits of ejected material as layers?

Back 77

Cinder cone volcano

Front 78

the profile of a cinder cone volcano is determined by

Back 78

Profiledetermined by maximum angle at which material remains stable instead of slidingdownhill.

Front 79

What kind of volcanos are –aka:stratovolcanoes–Layersof lava and pyroclasticsform hard surface, resists erosion–Steepsided profile

Back 79

Composite volcanoes

Front 80

STRATOVOLCANOES form _____ to strengthen its cone?

Back 80

Riblike dikes

Front 81

What kind of volcano has Andesite,high silica content

Back 81

STRATOVOLCANOES

Front 82

Stratovolcanoes have High Si magma is more viscousthan low Si magmaLava tends not to flow very farVolcanoes have steep slopesVents can block up and explode

Back 82

that is all

Front 83

•VolcanicDomes have what characteristics?

Back 83

–Thickflowing lava plugs the top of the volcano–Pressurebuilds up behind the dome–Violenteruptions

Front 84

Mt ST helens erupted in 1980 and had a crater what type of volcano was this?

Back 84

Volcanic dome and ejected pyroclastic content

Front 85

Was the direct blast from MT ST Helens straight up or tilted?

Back 85

It was tilted and had a bulge forming before it erupted

Front 86

what is –Collapsedevacuated magma chamber–Steepsided–Circular–40+km in diameter

Back 86

Caldera

Front 87

How does a caldera form

Back 87

A magma chamber ecplodes with gas rich magma and spread ash all over the surface once the gas is used up the surface collapses in on itself due to the ash forming a giant hole

Front 88

•Yellowstone– has 3 calderas when did they erupt?

Back 88

–(1.9mya)– 2,500 km3 of pyroclastic materials (2500larger than Mt St Helens),

–(0.6mya)– 1,000 km3 of ash & debris•

Yosemite’s Long Valley (BishopTuff)–170times larger than Mt St Helens –

1994CO2 releases denote magma activity

Front 89

Where are calderas and ash deposits abundant in?

Back 89

Western North America

Front 90

A shield volcano is slightly sloped at

Back 90

6-12

Front 91

what is flat to gentle slope?

Back 91

A Basalt plateau

Front 92

What kind of volcanoes are violent?

Back 92

Calderas and composite volcanoes

Front 93

hat kind of volcanoes are made of granite?

Back 93

Calderas

Front 94

What stratovolcano was near Naples, Italy and had –5-8meter ash flowIntermittentactivity in early – mid 1900s?

Back 94

Mt Vesuvius

Front 95

What are some risk assessments we can take to minimize the danger of volcanoes?

Back 95

•Regional prediction where volcanoes are most likely active.

Observe the kinds of rocks found for example granite can be a sign of caldera meaning a violent volcanoe. Basalt can be of a less dangerous volcanoes

Short term prediction by seeing lumps in mountains over time –Gas/ ash emission–Temperatureanomalies

Front 96

•Montserrat, 1997 - pyroclastic flows–1992earthquake swarms–1995steam /ash–predictionskept fatalities down to 19

Back 96

That is all

Front 97

•Mt St Helens, 1980 –`78Crandall & Mullineaux–1980Earthquake swarms, gas, ash–USGSpredictions averted even larger losses

Back 97

That is all

Front 98

What volcano caused –Ash& sulfur clouds–Solar radiation reaching Earth declined by 2-4%–Globalcooling – high alt dust reflects radiation

Back 98

•Pinatubo, 1991

Front 99

•Permian extinction, 225 mya–90%of marine species, 65% reptile & amphibians–Siberianflood basalts

Back 99

That is all

Front 100

•Mantle carbon–Basalteruption 0.44% weight/weight CO2––120mya– mid-Cretaceous superplumein Pacific Ocean – lowered temperatures +10-15°C••Volcanoes linked to both warming & cooling

Back 100

That is all

Front 101

Volcanoes are usually at what temperature before and after they erupt?

Back 101

Before its usually hotter after its cooler.