Geology Test 1

Front 1

what is geology?

Back 1

study of the earth+planets

Front 2

Why is geology important?

Back 2

Materials
Natural disasters
environmental issues

Front 3

What are the 3 major layers of earth's interior?

Back 3

core
mantle
crust

Front 4

what are the 3 parts of the outermost portion?

Back 4

Lithosphere
crust
asthenosphere

Front 5

what are some characteristics of the lithosphere?

Back 5

upper 100 km of earth
relatively rigid, solid, and composed of the upper potion of the mantle and all the crust

Front 6

what are some characteristics of the Asthenosphere?

Back 6

-upper portion of the mantle below lithosphere, 100 km thick
-not really solid, behaves like plastic
-lithosphere floats and moves over asthenosphere

Front 7

heating causes rock to expand and _____ density, causing it to _____

Back 7

decreases
rise

Front 8

where lithosphere is cold, it sinks into the

Back 8

asthenosphere

Front 9

a tectonic plate is

Back 9

broken lithosphere

Front 10

the whole process forms _____ _____ __ and creates ______ _____

Back 10

large convection cells
tectonic forces

Front 11

tectonic forces are forces that cause ______

Back 11

vertical and horizontal movement of the lithosphere

Front 12

there are 3 types of plate boundaries

Back 12

diverging
converging
transform

Front 13

what are some characteristics of diverging plate boundaries?

Back 13

exist where plates are moving apart
hot magma squirts up between the boundaries and create new oceanic crust
crust forming is dense, so it sinks lower in the crust

Front 14

what are some characteristics of converging plate boundaries?

Back 14

exist where plates move toward each other
oceanic plates will sink below the continental crust (called subduction zone)

Front 15

what are some characteristics of transform boundaries?

Back 15

exist where plates most past each other with no convergence of divergence
boundary forms a zone of large faults and earthquakes

Front 16

what is the age of the earth?

Back 16

4.6 billion years

Front 17

what are some evidence for continental drift?

Back 17

shape of coastlines
similar rock types
similar age of rocks
similar fossils
ancient climates are out of place

Front 18

What is paleomagnetism?

Back 18

study of ancient magnetism in rocks

Front 19

magnetite is cold ______

Back 19

magma

Front 20

magnetite is a _____ for where the magnetic poles were at during a specific period of time

Back 20

tracer

Front 21

who and what year was the theory of sea-floor spreading developed?

Back 21

Harry Hess
1962

Front 22

deep place where the ocean floor is being subducted is the ____

Back 22

oceanic trench

Front 23

what is the vine-mathews hypothesis?

Back 23

floor cracks, magma comes up, basalt forms, old crust is the melted and the process repeats itself

Front 24

diverging plates on land creates a valley called a _____

Back 24

rift valley

Front 25

name 3 types of converging plate boundaries

Back 25

ocean-ocean
ocean-continent
continent-continent

Front 26

the suture zone is the area where _____

Back 26

continents collide then fuse

Front 27

mantle plumes are ______ and when it comes out of the ground it is called a ___ ___

Back 27

fixed
hot spot

Front 28

Name the types of Atomic Bonding.

Back 28

Ionic
Covalent
Metallic
Wan Der Waal's forces

Front 29

type of bonding is ionic bonding?

Back 29

bonding by the attraction of negatively and positively charged atoms

Front 30

type of boding is covalent bonding?

Back 30

sharing of electron between atoms

Front 31

type of bonding is metallic bonding?

Back 31

freely moving electrons around closely packed atoms

Front 32

type of bonding is Van Der Waal's forces?

Back 32

weak bonds between sheets of bonded atoms

Front 33

name strongest to weakest bonds.

Back 33

covalent
ionic
metallic
Van der Walls forces

Front 34

Name the four most abundant elements in the crust

Back 34

1) oxygen
2)silicon
3)aluminum
4)iron

Front 35

what is silica and what percent of the earths crust do they compose?

Back 35

silica-oxygen bonded with silicon
90%

Front 36

silica tetrahedron

Back 36

four oxygen atoms packed around a single, much smaller silicon atom
total charge of negative 4

Front 37

what are isolated silicate minerals

Back 37

no oxygen atoms shared by tetrahedrons and are bonded by positively charged ions

Front 38

chain silicate structures

Back 38

oxygen atoms shared with adjacent silica tetrahedrons, bonded together by positive ions

Front 39

sheet silicate structures

Back 39

three oxygen aroms forming a sheet like structure bonded by positive ions

Front 40

framework silicate structure

Back 40

all four oxygen atoms shared with other tetrahedrons, forming a tree-dimensional or framework structure

Front 41

what are the 3 types of rock?

Back 41

igneous
sedimentary
metamorphic

Front 42

igneous rocks are

Back 42

rocks formed by the cooling of magma

Front 43

two types of igneous rocks are

Back 43

extrusive (at surface)
intrusive (below surface)

Front 44

lithified rocks are

Back 44

rocks that stick together

Front 45

lifhified sediments are called

Back 45

sedimentary rocks

Front 46

metamorphic rocks are

Back 46

sedimentary rock buried to great depths, heat and pressure to recrystallize the rock

Front 47

evidence that intrusive igneous rocks cooled below surface of the earth

Back 47

composition
intrusive igneous rocks contain minerals that form under high pressure
nature of intrusive contacts

Front 48

xenoliths are:

Back 48

pieces of country rock enclosed in an intrusive rock`

Front 49

composition of igneous rocks are classified as:

Back 49

felsic
intermediate
mafic
ultramafic

Front 50

felsic characteristics include:

Back 50

light colour
greater that 65% silica

Front 51

intermediate rocks characteristics are:

Back 51

medium-gray in color
silica percentage between mafic and felsic

Front 52

mafic rock characteristics are:

Back 52

dark-coloured
silica percentage ~50%

Front 53

ultramafic rock characteristics are:

Back 53

dark green to black in colour
silicia percentage: less than 45%

Front 54

Intrusive bodies include:

Back 54

volcanic necks
dikes
sills

Front 55

deep intrusive bodies include:

Back 55

pluton
stock
batholith

Front 56

a pegmatite is an:

Back 56

extremely coarse-grained intrusive igneous rock

Front 57

what are the 3 ways to form magma?

Back 57

heat rock till it melts
decrease pressure of a hot, dry rock
adding water to hot dry rocks

Front 58

3 processes that change the comp. of magma:

Back 58

differentiation by crystal settling
assimilation
mixing of magmas

Front 59

mafic rocks are most common in _____ crust

Back 59

oceanic

Front 60

felsic composition eruptions are more _____

Back 60

explosive

Front 61

James Hutton

Back 61

was the founder of the Plutonists
• Uniformitarianism – Laws of nature haven’t changed so that the “present is key to the past”
• Actualism - Natural laws governing both past and present processes on Earth are the same

Front 62

The use of radioactive elements has proven successful for determining absolute (Quantitative) ages because

Back 62

the rate of decay is constant for a particular element

Front 63

A geologic feature that cuts across another feature must be younger

Back 63

Principle of crosscutting relationships

Front 64

Strata extend until they terminate by thinning, grading into another type of sediment, or running into a barrier

Back 64

Principle of lateral continuity

Front 65

In undisturbed strata, the oldest rocks are at the bottom, and youngest rocks are at the top

Back 65

Principle of superposition

Front 66

different life forms existed at different times

Back 66

Principle of biological succession

Front 67

Sediments must have been deposited nearly horizontal and parallel to the underlying surface

Back 67

Principle of original horizontality

Front 68

Lord Kelvin attempted to provide an absolute geologic age for the Earth by

Back 68

calculating how long it took for the Earth to cool from a molten mass to its current temperature

Front 69

True

Back 69

According to the principle of inclusions, rock fragments included in another rock must be older than the surrounding rock. T/F

Front 70

_________ believed that the earth originally consisted of a hot, planet-wide ocean that cooled to precipitate rocks that formed mountains.

Back 70

Abraham Werner

Front 71

Rocks of the Precambrian period generally have few to no fossils contained within them. T/F

Back 71

True

Front 72

The rock age that is based on whether particular layers or bodies are older or younger than others is called

Back 72

relative age

Front 73

A geologic time scale was developed using relative time dating T/F

Back 73

True

Front 74

The absolute age of the Earth was estimated to be 1 million to 1 billion years using sedimentation rates. Which of the following is NOT a problem with sedimentation rates?

Back 74

need answer

Front 75

dolomite

Back 75

sedimentary rock

Front 76

schist

Back 76

metamorphic rock

Front 77

shale

Back 77

sedimentary rock

Front 78

gneiss

Back 78

metamorphic rock

Front 79

quartzite

Back 79

metamorphic rock

Front 80

evaporite

Back 80

sedimentary rock

Front 81

A mineral is not ______

Back 81

organic

Front 82

Clastic sedimentary rocks are ____ times more common than chemical sedimentary rocks.

Back 82

need answer

Front 83

Minerals that form by cooling of molten material form by ______.

Back 83

solidification

Front 84

Silicates form _______ percent of the Earth's crust.

Back 84

over 90

Front 85

A combination of high heat and/or pressure can lead to formation of minerals by __________.

Back 85

rearrangement

Front 86

Granite is a mafic rock. T/F

Back 86

False. Granite is a sialic (or felsic) rock.

Front 87

A ______ is an intrusion that cuts across layers.

Back 87

dike

Front 88

The metamorphic rock gneiss has weak foliation. T/F

Back 88

False

Front 89

_________ forms from hot ash and molten rock thrown into the air by a volcano.

Back 89

need answer

Front 90

Reefs form in shallow marine environments. T/F

Back 90

True

Front 91

The tremendous weight of sediment in a delta can cause the area to sink into the ocean. T/F

Back 91

True

Front 92

In a river, erosion occurs when water flows fast, deposition of sediment occurs when the river slows down. T/F

Back 92

True

Front 93

Playas form in ______ environments.

Back 93

arid

Front 94

Meandering streams require a ______ river gradient.

Back 94

low
low gradient and contorted pathway
Sands accumulate in the channels, while silt and clays accumulate in the floodplain

Front 95

Braided streams require a ______ river gradient.

Back 95

high
steep gradient and relatively straight river
deposits (fast moving water) tend to consist of gravels, sands, and silt

Front 96

The craton is

Back 96

a stable region with both crystalline and sedimentary rocks

Front 97

Tidal flats do not form where?

Back 97

in a beach environment.

Front 98

Sediments that form when a glacier melts are

Back 98

Glaciers deposit boulders to clay-sized material. This poorly sorted sediment forms a moraine.

Front 99

Fiords are U-shaped valleys that have been flooded by sea water. T/F

Back 99

true

Front 100

Gregor Mendel proposed the evolutionary theory of Natural Selection. T/F

Back 100

False

Front 101

proposed the theory of natural selection, which states that competition between members of a species ensures the survival of the fittest.

Back 101

Charles Darwin

Front 102

Gregor Mendel

Back 102

proposed the principle of inheritance, which states that traits are passed from adults to offspring through genetic inheritance.

Front 103

organisms acquire new traits in response to "inner wants" of the organisms

Back 103

Jean-Baptiste Lamarck

Front 104

genes are transmitted from adults to offspring carrying inherited traits

Back 104

Gregor Mendel

Front 105

Gregor Mendel

Back 105

genetic mutations can cause positive changes in a species and can be passed on to offspring

Front 106

more offspring are produced within a species than are able to survive

Back 106

Charles Darwin

Front 107

competition ensures those better adapted will survive and produce offspring

Back 107

Charles Darwin

Front 108

In younger rocks, fossils increase in complexity and diversity. T/F

Back 108

true

Front 109

In a marine ecosystem, the benthic province consists of the ocean floor. T/F

Back 109

True

Front 110

In marine ecosystems, the benthic province is on the

Back 110

bottom of the ocean

Front 111

In marine ecosystems, the pelagic province is

Back 111

the water above the ocean floor.

Front 112

In marine ecosystems, the epifauna live on top of the sediment in the benthic province. T/F

Back 112

True

Front 113

Gene exchange can occur between two different populations of different species. T/F

Back 113

False

Front 114

An ecological niche is a particular role that an organism plays in the environment. T/F

Back 114

True

Front 115

Possible causes of major extinctions do NOT include

Back 115

Floods

Front 116

The evolutionary model that suggests that evolution occurs slowly

Back 116

the gradualistic model

Front 117

What would be needed for early life?

Back 117

Availability of dissolved minerals
• Abundant water
• Mixing of fluids
• Energy sources

Front 118

To get life we need:

Back 118

Carbon, nitrogen, phosphorous, oxygen, and sulfur (these are abundant)
• Elements must combine to form amino acids and proteins (experiments of Miller)
• A protective membrane (we don't know much
• Organic phosphorous molecules about how
• DNA strands these happened)

Front 119

Ancient Heterotrophs

Back 119

Obtain food externally
• Digested this food externally (using enzymes)
• Fermented their food to make sugar

Front 120

Autotrophs

Back 120

Manufacture their own food
• May use CO2 + hydrogen sulfide or ammonia

Front 121

Photoautotrophs

Back 121

• Make food by photosynthesis
• Process CO2 into energy and excess O2
• Ancient types killed by O2

Front 122

Aerobic Organisms

Back 122

• Use oxygen to convert food into energy
• Efficient - lead to more complex life forms

Front 123

Prokaryotes (~ 3.5 BYA)

Back 123

– Simplest form of life
- Small 1-10 μm
– No cell nucleus
– DNA is spread throughout the organism
– Asexual reproduction

Front 124

Eukaryotes – First
appear 2.2 BY ago

Back 124

More complex cells - large 10-100 μm
– Cell nucleus
– DNA contained in nucleus
– Chromosomes
– Organelle
– Capable of sexual reproduction (which can
lead to more complexity)

Front 125

Origin of Eukaryotes Endosymbiotic Theory

Back 125

Aerobic bacteria are incorporated into prokaryotes
– Live symbiotically within prokaryotes
– Persist to future generations – become mitochondria – Cell nucleus forms
– Photosynthetic bacteria are incorporated and later become chloroplasts
– Mitochondria and chloroplasts have own DNA

Front 126

Cyanobacteria - Prokaryotes
(photosynthesis)

Back 126

Are the oldest fossils (3.5 BY ago -Archean Eon)
– Form stromatolites
• Mounds of sediment bound by sticky cyanobacterial mats
• First appear in the Archean and become more common later
• Provided oxygen to the early atmosphere

Front 127

Eukaryotes
– Acritarchs

Back 127

Unicelluar microfossils with resistant single-layered walls
• Related to phytoplankton (modern phytoplankton cause red tides)
• First appear ~1.6 BY ago
• Began to decline ~ 850 MY ago (neoproterozoic glaciation)

Front 128

Metazoans

Back 128

Multi-cellular organisms with tissues and organs
– Includes: soft corals, segmented worms, jelly fish, etc.

Front 129

In Earth’s solar system, the four rocky planets closest to the sun are

Back 129

Mercury, Mars, Venus, Earth

Front 130

Earth's early crust was felsic (sialic). T/F

Back 130

False. The Earth's crust was originally mafic (oceanic). Continental crust (felsic/sialic) began forming in the Archean when oceanic plates collided with one another.

Front 131

Plate tectonics during the Archean Eon are best described by the Wilson Cycle.

Back 131

False

Front 132

Most scientists now believe that life originated in

Back 132

mid-ocean ridges

Front 133

Repeated Wilson Cycles lead to an increased proportion of oceanic crust.

Back 133

False. Wilson Cycles add continental crust

Front 134

The shields of cratons developed during the Hadean. T/F

Back 134

False. Shields are stable regions within continents that represent the oldest rocks in the continent. They formed during the Archean.

Front 135

Amino acids are required for life. T/F

Back 135

true

Front 136

Plate tectonics originated in the Hadean. T/F

Back 136

False

Front 137

During the closure of an ocean basin in a Wilson cycle, which of the following does NOT occur

Back 137

Rifting. Rifting occurs in the early stages of the Wilson Cycle.

Front 138

If I had a compass and traveled back through time while remaining in the same location, my compass would always point north. T/F

Back 138

False

Front 139

The Hawaiian Islands are

Back 139

guyots

Front 140

The jigsaw fit of the continents is evidence of Continental Drift. T/F

Back 140

True

Front 141

The oldest rocks are in the center of

Back 141

an anticline

Front 142

The youngest rocks are in the center of a

Back 142

basin

Front 143

Endosymbiotic Theory

Back 143

Aerobic bacteria are
incorporated into
prokaryotes
– Live symbiotically within
prokaryotes
– Persist to future
generations – become
mitochondria
– Cell nucleus forms
– Photosynthetic bacteria are
incorporated and later
become chloroplasts
– Mitochondria and
chloroplasts have their own
DNA

Front 144

The Proterozoic Eon
• Divided into

Back 144

Paleo (old), Meso (Middle), and Neo (New)
• 2.5 BY to 544 MY ago

Front 145

Proterozoic Plate Tectonics

Back 145

Shields mostly Archean
• Proterozoic rocks often metamorphosed and form the platform
• Craton consists of both

Front 146

Wilson Cycle

Back 146

Oceans opened and closed
A) Stable Craton
B) Rifting due to convection cell
C) Development of a full ocean basin
D) Closure of the ocean,and subduction
E) Remnant ocean basincloses
F) Collusion Orogeny -Mountain building
G) Peneplained Mountains- Mountains erode

Front 147

The Wopmay Orogen shows evidence of

Back 147

a Wilson Cycle

Front 148

Wopmay Orogen

Back 148

Ocean opening
1) Normal faults (tension)
2) Basin sediments with volcanics
3) Passive continental margin:
a) quartz sandstones on the shelf
b) coastal plain clastic rocks
c) carbonate platform
d) turbidite deposits on the slope
Ocean Deepening/Closing
• Subduction to the east deepens basin
• Uplift causes basin to fill with
– sandstone on west
– shale to east

Front 149

Micro-Continent Collusion Orogeny

Back 149

Structural Deformation (Folding)
• Thrust Faults
• Granitic Intrusions
• Metamorphism

Front 150

Development of an Aulacogen: (failed arm of a rift)

Back 150

1) Hot spot causes crust to bulge
2) Stretched crust breaks into 3 arms
3) Two of the arms (rifts) widen and become continental margins
4) The third trends inland and becomes filled with
sediment and later fails – The third arm is the
aulacogen

Front 151

This process leads to
the 3 arms we see in aulacogens

Back 151

Triple junctions form when something is stretched in all
directions (e.g., shrinking clay)

Front 152

Rodinia formed during the

Back 152

Mesoproterozoic

Front 153

Rodinia Broke up in the

Back 153

Neoproterozoic

Front 154

Oxygen began to accumulate during the

Back 154

Proterozoic
Evidence:
– Banded Iron Formations:
• Without oxygen, iron was dissolved in the ocean
• Photosynthesis by algal stromatolites released oxygen into the ocean
• Iron precipitated as banded iron formations
• When the iron was exhausted, oxygen began to accumulate in the atmosphere (~ 2 BY Ago)

Front 155

Red Beds appear

Back 155

from 2 BY ago to present:
– Sandstones, siltstones and shales that contain oxidized iron - coloring the rocks red
– Require atmospheric oxygen
– Became more abundant through the Proterozoic

Front 156

Paleoproterozoic Ice Age:

Back 156

Evidence found north of Lake Huron
• Conglomerates
• Varved mudstones
• Glacial till
– Likely our planet’s first ice age

Front 157

Neoproterozoic Ice Age:

Back 157

Evidence found in Utah, Nevada, western Canada, Alaska, Greenland, South America, Scandinavia, and Africa
• Conglomerates
• Glacial boulders
• Glacial till – Ice sheets even covered land at the
equator
– Continents located near equator

Front 158

Cosmology

Back 158

the study of the universe

Front 159

Cosmologists estimate the age of the universe as

Back 159

15 to 18
Billion Years
– How do we know? We use the doppler effect and the red shift

Front 160

Our solar system contains 9 planets

Back 160

Four rocky planets close to the sun (Mercury, Venus, Earth, and Mars)
– Four gassy planets further away (Jupiter, Saturn, Uranus, and
Neptune)

Front 161

Cold Accretion Model for the origin of the earth

Back 161

A) Planet grows by accumulating dust
and particles
B) Gravity causes compression
– The Earth is homogeneous
– Internal temperatures increase
– Heavier elements sink
– Lighter elements rise
C) Differentiation yields the core,
mantle, and crust

Front 162

The Hadean Atmosphere

Back 162

Early Earth had a molten surface or thin, unstable crust
• Sustained by heat from abundant meteorites striking the
Earth and the decay of radioactive elements
• Primitive atmosphere probably comprised of Hydrogen
(H2) and Helium (He)
– Primitive gases lost to space early in Earth's history
– Weak gravity prohibited retention of lighter gases
– Dispersed by strong solar winds

Front 163

Early atmosphere was likely derived from

Back 163

volcanic
outgassing

Front 164

Hadean Ocean Formation

Back 164

Early gases highly reflective – nearly 60% of incoming
solar radiation blocked
• Resulted in planetary cooling and condensation of the
water produced by out-gassing
• Early rain vaporized upon hitting the still hot planetary
surface
• Eventually formed superheated water
• Finally collected into warm seas and oceans above and
around cooling crustal rock

Front 165

Shields of Cratons Developed During the

Back 165

Archean

Front 166

Archean Plate Tectonics

Back 166

Began ~3.5 billion years ago
• Different from today - 1) more dynamic; 2) very little continental
crust; 3) oceanic plates collided with each other

Front 167

Seismic waves

Back 167

Body waves:
P waves "push-pull, fastest, pass through solids, liquids, gases
S waves "right angle to wave movement", slower than P waves, pass through solids only
Surface waves - occur with P or S disturb the surface

Front 168

Wave that causes most damage in an earthquake

Back 168

Surface waves

Front 169

– Gutenburg Discontinuity:

Back 169

P waves slow
• S waves disappear
• Half way to Earth’s center (~ 2900 km)
• Transition between mantle and the outer core
• S waves do not travel through liquid – outer core is liquid

Front 170

Shadow Zone

Back 170

Due to refraction and reflection of
P waves

Front 171

Mohorovicic Discontinuity

Back 171

30-40 km below continents (~ 70 km below
mountains) and ~ 5-10 km below oceans. Zone where P wave velocity
increases. Transition between crust and mantle. Mantle - higher density and
more elastic - P Waves travel faster

Front 172

Core

Back 172

• Inner solid core
• Outer liquid core

Front 173

Mantle

Back 173

Lower Mantle
• Upper Mantle (includes
Asthenosphere – rock near its
melting point)

Front 174

Lithosphere

Back 174

Includes solid mantle and crustal
rocks

Front 175

Faults

Back 175

B) Normal Fault
– C) Reverse Fault
– D) Lateral Fault
– E) Oblique Normal
Fault with Rotational
Movement
– F) Thrust Fault

Front 176

to make a normal fault

Back 176

we need to pull the rocks apart (put the rock in tension

Front 177

To make a reverse fault

Back 177

we need to push the rocks together (compress the rock)

Front 178

to create a lateral (strike-slip) fault

Back 178

we need to shear the rocks

Front 179

types of folds

Back 179

A) Anticline
– B) Syncline
– C) Monocline
– D) Dome
– E) Basin

Front 180

transform faults form because

Back 180

spreading occurs at different rates along a spreading center

Front 181

Granite

Back 181

Felsic (Sialic) rocks

Front 182

Basalt

Back 182

Mafic rocks

Front 183

Transform Plate Boundaries occur

Back 183

where two plates
slide past one another – transform faults in oceans

Front 184

Thermal Plumes (Hot Spots) can form

Back 184

Island chains

Front 185

Continental Accretion

Back 185

Continents can Grow!
– Continents run into
• islands
• microcontinents
– that are “pasted” onto the continent

Front 186

Paleontology

Back 186

The study of ancient life

Front 187

Fossil

Back 187

Any remains, trace, or imprint of a plant or animal from
the geologic past that has been preserved in the earth's
crust
− Body Fossils: Actual remains of plants and animals
− Trace Fossils: Evidence of activity by organisms, e.g., tracks,
trails, and borings

Front 188

Carbonization:

Back 188

The organism is altered leaving behind a thin film
of carbon

Front 189

Mold:

Back 189

An impression made in sediment by organism

Front 190

Permineralization:

Back 190

Mineral precipitates into void spaces

Front 191

Petrification:

Back 191

Transformation into stone

Front 192

Replacement:

Back 192

Organic materials are replaced by minerals

Front 193

Cast:

Back 193

Secondary material fills a mold making a replica of the
organism

Front 194

Preservation in Amber:

Back 194

Insects are sometimes trapped in tree
resin that hardens to amber

Front 195

Freezing:

Back 195

Some areas never thaw, frozen organisms can be
preserved for long periods of time

Front 196

Worm Trails

Back 196

A) Crawling
B) Resting
C) Dwelling
D) Grazing
E) Feeding

Front 197

Index Fossils

Back 197

Used to correlate rocks from one region to another
• Characteristics:
− Rapid Evolution
− Short Vertical Range
− Many distinct Features
− Independent of Facies
− Strong, Hard Makeup for Good Preservation
− Geographically Widespread
− Occur in Large Numbers

Front 198

Species

Back 198

a group of organisms that have structural,
functional and developmental similarities and are able to
breed and produce fertile offspring

Front 199

There are six Kingdoms of Life

Back 199

Archaeobacteria
Eubacteria
Protista
Fungi
Pantae
Animalia

Front 200

Ecosystem

Back 200

defined by roles of life forms (producers,
consumers, and secondary consumers)

Front 201

Habitat

Back 201

Place
where an organism
lives

Front 202

Niche

Back 202

Particular
role that the
organism plays in
the environment

Front 203

Marine Ecosystem

Back 203

Divided into two realms:
• Benthic – Bottom of the
ocean,
• Pelagic – water above
ocean floor

Front 204

Benthic Province

Back 204

Supralittoral Zone – Beach, above high tide, harsh environment, few
plants and animals
− Littoral Zone – Beach, between high and low tide, crabs, etc that can
adapt to wet and dry conditons
− Sublittoral Zone – From low tide region to edge of continental shelf
• Epifauna – live on top of the sediment
• Infauna – burrowers and borers – live in the sediment
− Bathyal, Abyssal and Hadal Zones – Beyond the edge of the
continental slope, mainly scavengers that feed on the organic material
that rains down from above

Front 205

Pelagic Province

Back 205

Zooplankton – Planktonic animals (e.g., radiolaria, foraminifera, etc)
− Nekton: Swimmers – Invertabrates (e.g., shrimp, cephalopads);
Vertabrates (e.g., fish, whales, turtles)

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Jean-Baptiste Lamarck

Back 206

Acquired Characteristics
− Developed characteristics could be passed on

Front 207

Charles Darwin

Back 207

Natural Selection
− Variation always exists in a species
− More offspring produced than are able to survive
− Competition ensures those better adapted will survive and
produce offspring

Front 208

Gregor Mendel

Back 208

Principle of Inheritance:
− Genes are transmitted from adults to offspring and carry
inherited traits
− Genes are distinct segments of DNA
− Changes in traits are caused by random mutations and sexual
recombinations
− Mutations can cause positive change and be passed on

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Adaptive Evolution

Back 209

Dissimilar species develop similar traits
(bats and birds)

Front 210

Divergence evolution

Back 210

Similar species develop dissimilar traits – reduces
competition (seed vs nectar)

Front 211

Convergence evolution

Back 211

Similar ecological circumstances sometimes yield
similar adaptations (tree lizards on different islands look the
same, but are genetically very different)

Front 212

Punctuated Evolution

Back 212

Long periods with little
change
− Punctuated with brief
periods of rapid change
− More Common in Fossil
record

Front 213

Gradualistic Evolution

Back 213

All change is slow
− Numerous in between
forms
− Does occur rarely in fossil
record

Front 214

Extinctions possible causes

Back 214

Extraterrestrial Impacts
− Loss of Food Source
− Climatic Changes (Glaciation)
− Disease
− Competition
− Lowering of the Sea
− Human Competition

Front 215

Clastic rocks consist of:

Back 215

Clastic grains - Individual particles of rock or mineral
− Cements or Matrix - bonds the grains together
• Common Cements - Calcite or Quartz
• Matrix is often clay

Front 216

Clastic Sediments are classified based on grain
size, e.g.,

Back 216

Conglomerate - A mix of large grain sizes (e.g., lithified
gravel)
− Sandstone - Consists mainly of Sand (0.0625 -1.0 mm)
− Siltstone - Mainly silt (0.0039 - 0.0625 mm)
− Shale - Mainly clay (<0.0039 mm)

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Common Sandstones

Back 217

A - Quartz Sandstone: >90% quartz, mature
B - Arkose: > 25%feldspar, immature
C - Graywacke: > 30%clay and silt matrix,immature
D - Lithic Sandstone:< 15% matrix materials,
with rock (or lithic) fragments, immature

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Sedimentary Structures
• Ripple Marks: Symmetric

Back 218

Symmetric ripples form when a current moves back and forth
over an area – commonly in the intertidal zone of a beach

Front 219

Sedimentary Structures
• Ripple Marks: Asymmetric

Back 219

Asymmetric ripples form when a current in one direction (e.g., a
sand dune or a stream)

Front 220

Chemical Sedimentary Rocks
• Limestone

Back 220

Shallow marine environments
− Primarily from organic activity
− Calcareous shells, corals, and excretions
− Mainly in warm, clear water with minimal clastic input.

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Chemical Sedimentary Rocks
Dolomite

Back 221

Forms when calcium in a limestone is replaced by magnesium

Front 222

Chemical Sedimentary Rocks
Evaporites

Back 222

− Forms in arid regions - playa lakes
− Forms in restricted marine environments
− Requires high evaporation rates (dry)

Front 223

Sedimentary Facies
• Facies

Back 223

Lithologic or biogenic characteristics from
which the depositional environment can be inferred
Lithofacies can cross time lines
− A single type of rock may have different ages in different locations

Front 224

Lithofacies can cross time lines

Back 224

− A single type of rock may have different ages in different locations

Front 225

Facies onlap

Back 225

if the sea-level rises
(transgression)

Front 226

Facies offlap

Back 226

if the sea-level drops
(regression)

Front 227

Walther’s Principle

Back 227

Lateral Succession of Facies
• Often the lateral succession reflects the vertical
succession

Front 228

Each continent has a
craton consisting of a

Back 228

shield - ancient
crystalline rocks
− platforms - ancient flat
lying sedimentary rocks)

Front 229

The craton is bounded
by

Back 229

orogenic belts
(regions of deformed
younger rocks)

Front 230

Environments of Deposition

Back 230

3 types:
− 1) Continental
− 2) Marine
− 3) Transitional

Front 231

Continental Environments – Fluvial (River) Systems

Back 231

Most important process for transporting sediment from
mountains to lowlands and the oceans
− Erodes mountains and flattens topography
− River type depends on the gradient of the river:
• High gradient (e.g., in the mountains) – Braided stream
• Low gradient (e.g., the Mississippi Delta Region) – Meandering
stream

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Sediments in flowing water move by

Back 232

) traction, 2) saltation,
and 3) Suspension

Front 233

Water moves faster on

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steeper slopes (with high gradients)
Channel width also influences water speed
Water moves faster in the narrow part of the stream.
Erosion will be more likely there because the stream can carry larger particles. Deposition will occur when the water slows down.

Front 234

Alluvial Fans

Back 234

− Form at the foot of mountains
− Coarse sediments near the apex, fine sediments in the distal fan

Front 235

Eolian Deposits (Sand
Dunes)

Back 235

Form in arid environments from sediment (sand) transported by
wind

Front 236

Glacial Deposits

Back 236

Form in cold regions (in mountains or as continental ice sheets)
Ice moves fastest at the top, but is warmer at the base
Glaciers deposit boulders to clay-sized material
Glaciers erode mountain valleys into a U-shape

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Fiords

Back 237

U-shaped valleys that have been flooded by sea
water – Ocean levels rose after the last ice age.

Front 238

Lacustrine Deposits (Lakes)

Back 238

In glacial lakes,
turnover controls
sedimentation:
− Coarse sediment in
the summer
− Fine sediments (e.g.,
clay) settle out in the
winter
− Forms alternating
layers of coarse and
fine called varves

Front 239

Playa Deposits (Dry Lakes)

Back 239

− Form in arid environments – may be mudflats
May contain salt deposits

Front 240

Transitional Environments – Delta

Back 240

Where rivers deposit sediments into the sea
Delta deposits - broad expanses of mud deposits, crossed in places by meandering "ribbons" of sand
deposited in the river channels
• The tremendous weight of sediment in a delta can
cause the area to sink

Front 241

Transitional Environments – Tidal Flats

Back 241

Form in low-lying coastal areas
Sediments consist of muds, organic materials, and some sands

Front 242

Transitional Environments – Lagoon

Back 242

− Restricted from the ocean – often contains mud, silt, organic
material, and may contain evaporites

Front 243

Transitional Environments – Beach

Back 243

Beach sediments reflect nearby source rocks can vary from sands to gravel

Front 244

Transitional Environments – Barrier Island

Back 244

Separated from the shore by a lagoon
Has a combination of environments

Front 245

Marine Environments - Types

Back 245

Shallow Marine -Coast to continental shelf (submerged edge of continent) • <200 m deep
− Continental Slope/Rise - Sloping region from
continental shelf to deep sea −
Deep marine - Deep ocean beyond slope

Front 246

Marine Environments – Shallow Marine - Clastic

Back 246

Sands near the beach, fine grained mud away from the beach,
shells throughout, local organic rich sediments in deeper water

Front 247

Marine Environments – Shallow Marine – Reefs

Back 247

− Coral reefs grow in shallow water

Front 248

Marine Environments – Reefs

Back 248

Reefs grow on themselves, shed talus into deeper water, create shallow lagoons between the reef and the land

Front 249

Marine Environments – Continental Slope/Rise

Back 249

Sands, silts, and muds carried by turbidity currents (sediment laden underwater flows) in submarine canyons are deposited inthe deep marine (abyssal plain) environment

Front 250

Marine Environments – Deep Marine (Abyssal Plain)

Back 250

Mud, fine-grained carbonates, and chert deposits accumulate here

Front 251

Why do we need to know about minerals and rocks?

Back 251

Minerals often form under unique conditions.
• Conditions tell us about the environment in which the mineral formed
− Rock types can reveal the geologic history, for example:
• Sandstone can’t come from volcano (Forms when eroded grains accumulate)
• Granite does not form on the ocean floor (Forms deep below the Earth’s surface)

Front 252

Minerals - definition

Back 252

naturally occurring (natural vs. man-made diamond)
− crystalline solid (crystal structure) (gold vs. mercury)
− definite chemical composition (NaCl or SiO2)
− inorganic (salt vs. sugar)

Front 253

Ways that minerals form:

Back 253

solidification: Cooling of molten material
precipitation: Forming a solid from ions dissolved in water
rearrangement: Atoms in a solid are rearranged - requires water, heat, and/or pressure

Front 254

Minerals: solidification:

Back 254

Cooling of molten material
− Example: Slow cooling of underground molten rock

Front 255

Minerals: precipitation:

Back 255

Forming a solid from ions dissolved in water
− Example: Accumulation of salt (halite) in a saline lagoon

Front 256

Minerals: rearrangement:

Back 256

Atoms in a solid are rearranged - requires
water, heat, and/or pressure
− Example: Metamorphic minerals derived from other minerals

Front 257

Minerals: Polymorphs

Back 257

Same chemical composition, but
different crystal structure
− Diamond and graphite are different minerals, both made of pure
carbon

Front 258

Mineral Groups:

Back 258

native elements: copper - Cu
• oxides/hydroxides: hematite, brucite
• halides: halite - NaCl
• carbonates: calcite - CaCO3
• sulfates/sulfites: anhydrite. pyrite - FeS2
• silicates: quartz – SiO2, olivine - Mg2SiO4

Front 259

Silicates

Back 259

over 90% of the earth's crust
feldspars, micas, amphiboles, pyroxene, olivine, clay minerals

Front 260

Quartz

Back 260

Very common - Hard Minerals
− Gem varieties of quartz:
amethyst, citrine, rose quartz,
− Microcrystalline quartz:
agate, chert, flint, jasper

Front 261

Feldspars

Back 261

the most abundant - 60% of the earth's crust
by weight.
− Orthoclase - potassium (K) feldspar
-Plagioclase - Sodium Calcium (Na,Ca) feldspar

Front 262

Micas

Back 262

muscovite and biotite

Front 263

Sedimentary rocks

Back 263

• Accumulation and cementation of mineral grains
− e.g., Sandstone
• Chemical precipitation
− e.g., Limestone

Front 264

Igneous Rock Types

Back 264

Intrusive Igneous Rock -
• Solidified underground
Extrusive Igneous Rock
• Solidified at the surface,
• Usually forms from Volcanoes

Front 265

Intrusive Igneous Rocks
• Forms:
− Pluton:

Back 265

Massive igneous bodies formed at depth

Front 266

Intrusive Igneous Rocks
• Forms:
− Sill:

Back 266

Horizontal intrusion between existing layers of rock

Front 267

Intrusive Igneous Rocks
• Forms:
− Dike:

Back 267

Intrusion that cuts across existing layers (cm to
hundreds of meters)

Front 268

Intrusive Igneous Rocks
• Forms:
− Vein:

Back 268

Deposit of foreign minerals within a rock fracture

Front 269

Extrusive Igneous Rocks
• Forms:
− Lava:

Back 269

Magma (molten rock) that has flowed to the surface

Front 270

Extrusive Igneous Rocks
• Forms:
− Pyroclastic Rock (Tuff):

Back 270

Hot ash and magma thrown into the
air, settled, and cooled

Front 271

Igneous Rocks - Other Textures (cont)
• Forms:
− volcanic glass

Back 271

either lava or pyroclastic, no crystals
• obsidian - volcanic glass with no bubbles, solid rock,
generally black

Front 272

Igneous Rocks - Other Textures
• Porphyry -

Back 272

a mix of fine crystals with larger crystals
(phenocrysts)

Front 273

Igneous Rocks - Other Textures
• Porphyry -

Back 273

Slow cooling magma begins forming
crystals. If then cooled quickly, small crystals form and
encase the larger phenocrysts.

Front 274

Igneous rock names are based on

Back 274

mineral composition
and texture

Front 275

Sedimentary Rocks
• Divided into two categories:

Back 275

− Clastic Rocks - formed from accumulation of particles
− Chemical - formed by precipitation of dissolved particles

Front 276

Clastic Sedimentary Rocks
• Types are based on size (sometimes shape) of particles

Back 276

Conglomerates - Poorly sorted sediment including gravel
− Breccia - Angular clasts
− Sandstone - Sand
− Siltstone - Silt
− Mudstone and Shale – Mud and clay
− Descriptors are often added, e.g., calcareous shale (shale made mostly of calcite particles)
− Some are named based on composition, e.g., arkose (sandstone made of quartz and feldspars)

Front 277

Sedimentary Rocks
• Chemical - formed by precipitation of dissolved particles

Back 277

Limestone - Calcareous sand, mud, coral and/or shells
(CaCO3)
− Dolomite - Similar to limestone but some Ca replaced with Mg
− Evaporite - Salts (gypsum, halite, borax)
− Chert - Nodular - SiO2 replacement in limestone bedded - siliceous shells (microscopic)
− Organics - organic debris (peat and coal)
− Iron Oxides - common in deep soils

Front 278

Metamorphic rock grades:

Back 278

High-grade - formed at high temperature or pressure
− Low-grade - formed at low temperature or pressure

Front 279

Metamorphic rock Compositional alteration

Back 279

rearrangement of atoms in minerals resulting in new minerals (temp or press)
• The types of Minerals are controlled by temperature and pressure (stability relationships). Results in a progression in mineral types.

Front 280

Metamorphic rock Textural alteration

Back 280

Alteration of the texture of the rock
• Recrystallization - results in a new texture (ex: larger or intergrown crystals), caused by pressure or heat
• Deformation - altering the shape of minerals (pressure)

Front 281

Nicolas Steno

Back 281

− Principle of Superposition
Principle of Original Horizontality
Principle of Lateral Continuity
Developed Stratigraphy - The study of layered rocks

Front 282

Abrahm Werner

Back 282

Lead the Neptunists

Front 283

Charles Lyell

Back 283

Principle of Crosscutting Relationships
Principle of Inclusions

Front 284

William “Strata” Smith

Back 284

− Principle of Biological Succession –
• Rock units often contain unique fossils
• These fossils represent a unique time period
• Unique fossils can be used to identify time-equivalent rocks

Front 285

Cuvier and Brongniart

Back 285

Founded vertebrate paleontology
− Paleontology: The study of all ancient life forms, their interaction, and their evolution
− Catastrophism - Believed history of earth

Front 286

Geologic Time Scale Phanerozoic –

Back 286

“evident life”. Only 1/8 geologic time, but represents 90% of what we know about life on earth.

Front 287

Geologic Time Scale Precambrian–

Back 287

“Hidden Life” Poor or no fossil record.

Front 288

Geologic Time Scale -
• System versus Period

Back 288

System is used for rocks
− Period is used for time

Front 289

Relative Age Dating

Back 289

Order of events tells older vs. younger
− Doesn’t require actual age or actual time
− Uses the principles of geology:
• Superposition, Lateral Continuity, Cross-Cutting , Relationships, Inclusions

Front 290

Absolute Age Dating − Bishop Usher -

Back 290

• Used ages of people in the Bible
• Earth created in 4004 B.C Oct 26, at 9:00 am.
• Problem: Doesn’t match geologic evidence

Front 291

Absolute Age Dating −− Sedimentation Rates -

• Problems

Back 291

Sedimentation has no
− uniform rate
− compaction rate
− erosion rate

Front 292

Absolute Age Dating
− Seawater Salinity -

Back 292

• When water evaporates, it becomes saltier
• Estimate: 90 million years.
• Problems: Doesn’t account for salts leaving water

Front 293

Absolute Age Dating
− Cooling Rate -

Back 293

• Lord Kelvin calculated how long for the earth to cool from a molten mass to its current temp
• Estimate: 24 – 40 million years
• Problem: Heat from Radioactive Decay slowed this process

Front 294

Absolute Age Dating - Continued
− Radioisotope Dating -

Back 294

Atoms are the smallest particle of matter that can form an element
Unstable isotopes decay to a more stable form by emitting radiation
Once an unstable nucleus decays it forms a new atom called a “daughter element”
Daughter elements may be unstable and decay again forming “Decay Series”

Front 295

Radioisotope Dating – Methods
Half-life concept – critical to radioisotope age dating

Back 295

The half life is the time required for 50% of the parent nuclide to decay into a daughter nuclide.
− The rate of decay is constant and unaffected by changes in pressure, temperature, or chemistry.
− Each isotope has a unique half life.
− We can not predict when a particular atom or particle will decay, only know that, on average, half of a sample will decay during the span of one half life.
− If the parent nuclide is trapped within a mineral, thenthe ratio of the parent to daughter nuclide can be used to determine the minerals age.