Geology 101 Cumulative Final Exam University of Alabama

luster

the way light is reflected by the surface of a mineral. Two luster groups are METALLIC and NON-METALLIC

Color

Results from a mineral's chemical composition, impurities that may be present, and flaws or damage in the internal structure.

Color is not a diagnostic way to identify minerals.

Streak

Color of a mineral when powdered.

Hardness

resistance to scratching.

Cleavage

tendency to break along flat planes which represent where the bonds between atoms are weaker.

Lava

extruded and cooled onto the earth's surface from volcanoes.

Magma

molten rock that cools below the earth's surface

Composition is controlled by the type of plate tectonic environment in which _____ or _____ forms.

magma, lava

What are the 4 types of composition for igneous rocks?

1. Felsic

2. Intermediate

3. Mafic

4. Ultramafic

Felsic

high amount of quartz and feldspar, light colored igneous rock. white and pink color

Intermediate

"middle" composition between felsic and mafic. gray color.

Mafic

High. Dark color

Ultramafic

very dark. commonly green due to the presence of olivine

Two examples of Volatiles

water, CO2

Igneous rock textures

phaneritic

porphyritic

aphanitic

vesicular

glassy

pyroclastic

Physical weathering

breaks down rock into smaller fragments of rock

Chemical weathering

breaks down internal structures of the minerals in the rock, and the minerals are dismantled ion by ion.

What is the most important chemical weathering agent?

Water

Lithification

occurs after the fragments have been buried, compacted, and cemented.

Types of sedimentary rocks

clastic

chemical

biochemical

organic

Sorting

refers to the degree of uniformity of partial size within a sediment

A well sorted rock has usually traveled far from its source.

Geologic maps

represent the type of rock unit that is visible at the surface of the land.

Strike

is always perpendicular from the direction of the dip

Dip

the number of degrees that the bed is tilted from horizontal.

Fold

rock layers that have been compressed to bend in different directions

Stress

force applied over a given area

Aquifer

a geologic stratum that is completely saturated with water and sufficiently permeable to transmit economic quantities of water to wells and springs.

sediment or rock that transmits water easily

has high porosity and high permeability

Permeability

the ability of the geologic stratum to transmit water - the ease of flow of water through a geologic media.

the degree to which a material allows fluids to pass through it via an interconnected network of pores and spaces

Porosity

the percent of pores space available for water to reside - the ratio of void spaces in a rock or sediment to the total volume of the rock or sediment

The total volume of empty space (pore space) in a material, usually expressed as a percentage

Hydraulic conductivity

describes how well a fluid moves through a particular geologic stratum. Describes the physical characteristics of the sediment and the characteristics of the fluid flowing through that sediment.

Aquitards

restrict the flow of water and are typically associated with clay layers in the subsurface

sediment or rock that does not transmit water easily and therefore slows down or stops the motion of water

low porosity and low permeability

water-table

the surface that joins the unsaturated zone and the saturated zone.

it is the bottom of the unsaturated zone.

artesian well

when water flows freely to the surface from a well.

a well in which water rises on its own due to angled bedrock and natural pressure within the system

Spit

partially blocks a bay mouth

baymouth bar

entirely blocks a bay mouth

Barrier island

a section of a spit or a baymouth bar breaks off from the larger sandbar

An offshore bar that rises above sea level, forming an island

Groin

lines of rock set perpendicular to shore to trap sediments moving with longshore drift.

A concrete or stone wall built perpendicular to a shoreline in order to prevent longshore drift from removing sand

Jetties

extend out from the mouths of rivers, bays, and inlets to maintain deep shipping channels.

How old is the universe?

13.7 billion years old

As the universe cooled, what two gases were most abundant?

Hydrogen - 74%

Helium - 24%

how many elements naturally occur in the universe?

92

Planet

an object that orbits a star, is spherical, and has cleared its neighborhood of other objects

Asteroid

chunks of rock and/or metal

Comet

chunks of mostly ice with a path that sometimes approaches the sun

What protects us from most solar wind?

The magnetic field

Earth's atmosphere is made up of:

78% nitrogen

21% oxygen

Mineral

a solid, natural substance in which atoms are arranged in an orderly pattern

Glass

a solid in which atoms are not arranged in an orderly pattern

Rock

an aggregate of mineral crystals or grains, and masses of natural glass

Consolidated material that usually underlies regolith but is sometimes directly exposed at the ground surface

sediment

loose mineral grains that are not stuck together

metal

solids composed of metal atoms

alloy

a mixture of more than one type of metal atom

melt

is formed when solid materials become hot and transform into liquid

Example: molten rock

Organic compounds

carbon-containing compounds that either occur in living organisms or have characteristics that resemble compounds in living organisms

Silica

a compound of silicon and oxygen

Silicate minerals are...

the most common minerals on earth

Examples: olivine, pyroxene, hornblende, and quartz

the nature of the core of the earth generates its

magnetic field

Lithosphere

all of crust plus part of the upper mantle. is rigid

asthenosphere

portion of mantle that can flow (not liquid)

divergent boundary

plates move away from each other

convergent boundary

plates move toward each other

transform

plates move alongside each other

Volcanoes typically occur at what type of plate boundary?

A convergent. Specifically, oceanic - continental

Oceanic islands typically occur at what type of plate boundary?

Convergent. Specifically, oceanic - oceanic

Mountains typically occur at what type of plate boundary?

Convergent. Specifically, continental - continental

Hot spot

a location at the base of the lithosphere, at the top of a mantle plume, where temperatures can cause melting.

Element

a material that is made up of only one type of atom

Atom

smallest piece of an element that has the properties of the element.

atomic number

the number of protons in an atom.

atomic weight

the number of protons plus neutrons in an atom

Ion

an atom with an unequal number of protons to electrons

Mineral

a naturally occurring solid, formed by geologic processes, that has a crystalline structure and a definable chemical composition.

Viscosity

the resistance to flow.

Stratovolcanoes occur at what type of plate boundary?

Convergent

Shields volcanoes occur above...

hot spots

Cinder cones develop at

continental rifts

Active volcano

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

Dormant volcano

volcanoes that have not erupted for hundreds or thousands of years, but have the potential to erupt again

Extinct volcano

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

uniformitarianism

the principle that the same physical processes observed today are responsible for the formation of ancient geological features

"the present is the key to the past"

superposition

the principle that younger layers of sediment are deposited on older layers of sediment; thus, a sequence of strata (the oldest layer) is at the base

What type of rocks tell us more about the earth's history than any other type?

sedimentary rocks

sedimentary rock

rock that forms either by the cementing together of fragments broken off preexisting rock or by the precipitation of mineral crystals out of water solutions at or near the earth's surface

Five fundamental steps are involved with the formation of clastic sedimentary rocks

1. Weathering

2. Erosion

3. Transportation

4. Deposition

5. Lithification

Hydrolysis

water reacts with a mineral to form a new mineral with water as part of the crystal structure

Erosion

the combination of processes such as wind, water, ice, and gravity, that separate rock pieces from rock and carry it away

Transportation

movement from one location to another by wind, water, or ice

deposition

process by which sediment settles out of the transportation medium

lithification

the transition of loose sediment into solid rock.

Metamorphic rock

rocks that form when preexisting rock changes into new rock as the result of an increase in pressure and temperature and/or shearing under elevated temperatures

Shear

when one part of a material moves sideways, relative to another

compression

a push or squeezing felt by a body. can be either vertical or horizontal

Shale

sedimentary rock composed of mafic and felsic clay minerals with platy texture

Hypocenter of an earthquake

the place underground where rock breaks and generates earthquake waves

Epicenter of an earthquake

the point on the surface of the earth directly above the focus (hypocenter)

Fault

a fracture (crack) in the earth's surface on which sliding (movement) occurs

Body waves

seismic waves that pass through the interior of the earth

P-waves, S-waves

Surface waves

seismic waves that travel along the Earth's surface

L-waves, R-waves

P (primary) -waves

Compressional seismic waves that move through the body of the earth

non-destructive

S (secondary) -waves

Seismic shear waves that pass through the body of the earth

non-destructive

Is the second wave felt at a distance away from the hypocenter