GEOL 1403 FINAL

Earth consists of two types of crust: lithospheric and oceanic.

False

what are the terrestrial planets?

Mercury, Venus, Earth, Mars

observed in vertical cross section, soil is made up of distinct layers. from the surface downward, the layers are designated ______.

O, A, E, B, and C

most sand on beaches, in desert dunes, and in stream and river channels is made up of______.

SiO2

Basalt and gabbro are compositional equivalents, which means that they ____.

are made up of the same minerals but have different textures

feldspars ______.

are nonferromagnesian silicates

ionic bonds occur when electrons ______.

are transferred between atoms

when an atom undergoes alpha or beta decay, it _______

becomes a completely different element

the concept of metamorphic facies ______

cannot be use in areas where the original rocks were pure quartz sandstone

the most common chemical sedimentary rocks are ________.

carbonate

during an earthquake, seismic waves _________

cause shaking and damage to structures

lithification of sand and gravel requires both compaction and ______.

cementation

weathering is classified as either mechanical or _______.

chemical

horizon a in a soil is _____.

composed mostly of clays and stable minerals

Earth's core is likely to be ____.

composed primarily of iron

divergent plate boundaries are characterized by ________

contact metamorphism only

one reason that sedimentary rocks are important in deciphering earth history is that they _____.

contain fossils that are rare or absent in other types of rocks

calcium carbonate readily dissolves in water that ______.

contains a small amount of carbonic acid

what are the three major types of plate boundaries?

convergent, divergent, and transform

An easy way to visualize plate movement is to think of a(n) ____.

conveyer belt moving luggage from one place to another

an igneous rock with no visible crystals ____.

cooled quickly on earth's surface

a rock composed almost entirely of fragmented seashells is called ________.

coquina

which subsystem of earth supplies heat for convection in the mantle?

core

during spheroidal weathering of a rectangular stone, the _______.

corners are attacked y weathering from three sides

chemical sedimentary rocks can have a clastic texture or an interlocking grain texture called ______.

crystalline

A resource is a naturally occurring concentration of solid, liquid, or gaseous material in or on Earth's crust in such a form and amount that economic extraction of a commodity is ____.

currently or potentially feasible

the degree of metamorphic change within an aureole _______

decreases with distance from the intrusion

marine transgressions are created when _____.

deposition occurs during a time when sea level rises and the shoreline moves inland

detrital sedimentary rocks are _____.

derived from parent material and usually classified by the size of their constituent particles

mantle plumes and hot spots help geologists ______.

determine both direction and rate of plate movement.

divisions in geologic time represent _______

distinct changes in the rock record

any aspect of geology concerned with the search for minerals and rock of economic value is called ______ geology.

economic

What are the subdivisions of the geologic time scale, listed in order from longest to shortest time intervals?

eon, era, period, and epoch

the longest divisions of geologic time are called _____

eons

if the p-s time intervals are known from at least three seismograph stations, the _____ of any earthquake can be determined.

epicenter

rock salt and rock gypsum are both examples of ______.

evaporites

blue schist facies indicate ______

evidence of an ancient subduction zone

a unique physical property of water is that it ______.

expands when it freezes

pyroclastic igneous rock forms from ______.

explosive volcanic activity

Most lava temperatures are taken at volcanoes that show little or no explosive activity because ____.

explosive volcanoes cannot be approached safely

Oceanic ridges are geologically stable features made up almost entirely of sedimentary rock.

false

because large intrusions, such as batholiths, have such a large surface area they cool quickly and only a relatively small area of surrounding rock undergoes metamorphism

false

bowen's reaction series explains the order of mineral formation with decreasing pressure.

false

crystal settling involves gravitational settling of melted minerals.

false

thermal expansion and contraction occur because rock is an excellent conductor of heat.

false

various colors of slate result from differing intensities of deformation.

false

soil develops ______.

faster on unconsolidated sediment than it does on bedrock.

magmas with the highest percentages of silica are called ____.

felsic

Aphanitic, phaneritic, and porphyritic are terms that indicate ____, respectively.

fine-grained, course-grained, and mixed grained crystal sizes

what parallel alignment of minerals is caused by the application of pressure, and gives a rock a layered or banded appearance?

foliation

a half-life is the amount of time required ______.

for one-half of the parent isotopes to decay to daughter isotopes

______ are type of lithostratigraphic unit with distinctive upper and lower boundaries

formations

If the continents were once joined together, rocks and mountain ranges on the margins of each should have ____.

formed under the same conditions and in the same sequence

rock units can be correlated best by examining _____

fossil data, rock types, and key beds

poorly-sorted sediment has _______.

great size variation

a mineral's resistance to abrasion is called _____.

hardness

earth's core _______

has both liquid and solid components

isotopes of the same element ____.

have different numbers of neutrons but the same number of protons.

Geologists know that oceanic ridges are geologically very active because they ____.

have many small earthquakes and are the site of recent volcanic eruptions

what is the driving mechanism for plate tectonics?

heat deep within earth

what technique injects fluids under very high pressure into organic-rich shales to recover trapped natural gas?

hydraulic fracturing

Many metallic mineral deposits such as copper, gold, lead, silver, tin, and zinc are related to igneous and associated ____ activity.

hydrothermal

reaction of country rock with solutions from a cooling magma is known as ______ alteration

hydrothermal

Tentative explanations that are formulated to explain observed phenomena are known as ____.

hypotheses

what comprises the ocean crust?

igneous crust

frost action is most effective _____.

in high mountains

the process of assimilation _____.

includes melting and incorporation of inclusions of country rock

a seismic risk map can be used to _______

indicate the likelihood and potential severity of future earthquakes

a laccolith forms when a sill ____ and causes the overlaying rocks to ____.

inflates; bow upwards

one possible way to decrease the magnitude of an earthquake is to _____.

inject fluid into fractured rocks

plutons originate through _____ activity.

intrusive igneous

contact metamorphism ______.

is also known as thermal metamorphism

most gravel ______.

is made up of rock fragments

humus _______.

is the dark, organic material formed by bacterial decay

A continental margin ____.

is the transition zone from the exposed land to the ocean floor

continental crust _________

is usually described as "granitic"

the seattle, washington area ______

is very likely to have a large earthquake in a foreseeable future

the principle of _______ states that rock layers extend laterally in all directions unless or until they terminate in one of a number of natural means

lateral continuity

index, or guide, fossils are most useful because they _______

lived during a brief period of geologic time

for a neutrally-charged atom to become a positively-charged atoms of the same element, it must ____.

lose an electron

erosion is ______.

made worse by plowing, overgrazing, and deforestation

natural glass such as obsidian forms when _____.

magma cools too rapidly for crystals to form

What is produced by the combination of thermal and compositional convection within Earth's liquid metallic outer core and Earth's rotation?

magnetic field

salinization of soils ______.

makes them unfit into agriculture

the region between two adjacent isograds _______

makes up a single metamorphic zone

what is the zone between earth's core and crust?

mantle

below the outermost layer of earth lies the ________, which accounts for more than ________ of earth's volume

mantle; 80%

many ore deposits result from contact metamorphism during which hot, ion-rich fluids ______.

migrate from igneous intrusions into the surrounding rock

What are naturally occurring, inorganic, crystalline solids that have definite physical and chemical properties?

minerals

although metamorphism is associated with all three types of plate boundaries, it is _______

most common along convergent plate margins

erosion is the ______.

movement of weathered material from its source site

a hiatus between igneous or metamorphic rocks and sedimentary rocks is represented in the rock record by a ______

nonconformity

intraplate earthquakes _____.

occur when there is stressed caused by compression

regional metamorphism

occurs over a large area

magnetic reversals _____.

occurs when magnetic north and magnetic south poles switch positions.

what are two types of crust?

oceanic and continental

most earthquakes occur along the circum-pacific belt primarily because _______.

of the convergence along plate boundaries

radiocarbon dating is possible primarily because ______

organisms stop accumulating carbon-14 when they die

all silicate minerals contain the elements silicon and _____.

oxygen

The chemical formula of calcium carbonate is CaCO 3. The number three (3) in this formula represents the ratio of ____ in the mineral.

oxygen atoms to carbon atoms

a measure of hydrogen ion concentration is known as _____.

pH

the composition of the mantle is primarily _______

peridotite

what is the study of earth materials and the processes operating within earth and on its surface?

physical geology

volcanoes have a cylindrical conduit know as a volcanic ______ that connects to an underlying magma chamber.

pipe

what unifying theory of geology holds that large segments of earth's outer part move relative to one another?

plate tectonic theory

At transform plate boundaries, ____.

plates move laterally past each other and crust is neither produced or destroyed

_____ is known to be a dwarf planet.

pluto

interest in continental drift waned until studies of Earth's magnetic field and oceanographic research showed that _____.

present-day ocean basins are not as old as continents but instead, are geologically young features that resulted from the breakup of Pangaea

the two types of body waves are ______ and ______ waves

primary; secondary

what are the relatively massive, positively-charged particles in the nucleus of an atom called?

protons

one example of a vesicular felsic rock is _____.

pumice

a fossil is determined to be 175,000 years old. this is an example of a ______ date

radiometric

the most useful method for dating the oldest events one earth is ________

radiometric dating of rocks and fossils

shields are _____.

regions of the continents where basement rocks are widely exposed

the difference in elevation between high and low points in a region is called _______.

relief

Hydrocarbons are formed largely from the ______.

remains of microscopic organisms

clay particles in soil are important in soil development because they _____.

retain water and supply nutrients

stoping is the process in which ______.

rising magma detaches and engulfs pieces of country rock

pressure release occurs when _______.

rocks are uplifted and eroded

the most common and effective agent for transporting sediment is ______.

running water

a type of mechanical weathering is ______ and a type of chemical weathering is ______.

salt crystal growth; hydrolysis

what type of rocks form at or near earth's surface?

sedimentary rocks

One of the best-known transform faults is the San Andreas Fault in California. This fault ____.

separates the Pacific plate from the North American plate

a major characteristic of graded beding is that the rock layers ______.

show an upwards decrease in grain size

an example of a native element is ______.

silver

which list of foliated rock types is arranged correctly according to increasing coarseness of texture?

slate, phyllite, schist, gneiss

fossils are common because _______.

so many billions of organisms lived during the past

gondwana consisted of which current continents?

south america, africa, australia, antarctica, and india

____ is the study of composition, origin, areal distribution, and age relationships of layered rocks

stratigraphy

the geologic time scale was initially put together by _____

superposition, fossil succession and correlation

when a rock is broken into smaller pieces, its _______.

surface area increases but its volume remains the same

______ has a distinctive soap feel, ______ writes on paper, and _____ tastes salty.

talc; graphite; halite

the basic building block of all silicate minerals in the silica _____.

tetrahedron

most igneous rocks are classified as either volcanic or plutonic based on their ____.

texture and composition

the term pegmatite refers to an igneous rock with a particular _______ rather than a specific _____.

texture; composition

when an atom of uranium-238 undergoes alpha decay, it becomes ______

th-234

cleavage is ______.

the breaking of minerals along smooth planes of weakness determined by the strength of their chemical bonds

minerals are ______.

the building blocks of rocks

A clast (inclusion) of granite found in a conglomerate is determined to be one hundred million years old. What does this information suggest about the conglomerate?

the conglomerate is younger than 100 million years

Divergent plate boundaries most commonly occur along ____.

the crests of oceanic ridges

the lithosphere is made up of the ________

the crust and upper mantle

the magnitude of an earthquake measures _______

the energy released

Glacially deposited strata were important in the development of continental drift theory because ____.

the glacial deposits indicated that all of the southern continents must have been closer to the South Pole and contiguous

conglomerate is common, but sedimentary breccia is not. why?

the gravel becomes rounded very quickly during transport

what factor is least likely to affect earthquake intensity?

the magnitude of the last recorded earthquake

as s- and p-waves travel farther, ________

the p-s time interval increases

which principle states that fossil assemblages succeed on another through time in a regular and predictable order?

the principle of fossil succession

Geologists use ____ and their knowledge of present-day depositional processes to make determinations about a rock's depositional environment.

the principle of uniformitarianism

foliation indicated that ______ during metamorphism

the rock was subjected to heat and differential pressure

what is an atom?

the smallest particle into which an element can be divided while still retaining the chemical characteristics of that element

the Curie Point is_______.

the temperature a which iron-bearing minerals gain their magnetization.

what theory has the central thesis that all present-day organisms are related and that they have descended with modifications from organisms that lived in the past?

theory of organic evolution

during metamorphism, the original rock undergoes changes _____.

to achieve equilibrium with its new environment

Plate movement plays a major role in the present non-random distribution of plants and animals.

true

The solar nebula theory of the formation of the solar system accounts for the differences in composition between the terrestrial and Jovian planets.

true

luster is the quality and intensity of light reflected from a mineral's surface.

true

mafic lava tends to be fluid, whereas felsic lava is much more viscous.

true

many geologists now think that hot-spot volcanism results from a rising mantle plume.

true

metamorphic rocks are very common in the crystalline basement rocks of shields .

true

differential pressure ________

typically occurs when two plates collide

p-waves travel faster than s-waves _______.

under all circumstances

a sedimentary rock in which all the grains are about the same size can be characterized as ________.

well-sorted

metamorphism takes place _______.

while rocks remain solid

horizon B has fewer organisms and less organic matter than horizon A. this horizon is also called the _____.

zone of accumulation

suppose an isotope has a half-life of 50 million years, and 1/8 of sample remaining consists of that isotope. what is the age of the rock from which it was taken?

150 million years

a very strong earthquake recorded in north america was the intraplate quake known as the _______ earthquake

1811 new madrid

what is the approximate age of earth?

4.6 billion years

almost _____ % of earthquakes take place along plate boundaries

95

a key characteristic if igneous rock is that they _____.

are made up of minerals that crystallized from molten rock matter called magma

Features associated with convergent plate boundaries include volcanic island arcs, oceanic trenches, and mountain belts.

True

Geologists use the Principle of Uniformitarianism as a basis to interpret the past and predict the future.

True

who was the first person to suggest that all of the continents had originally been joined together as the supercontinent Pangaea?

alfred wegener in 1912

what is the loss of of two protons and two neutrons from the nucleus called?

alpha decay

a mineral's specific gravity and density ______.

are controlled by its structure and composition.

all minerals _______.

are crystalline, inorganic, and naturally occurring

sedimentary structures ______.

are features that form as a result of physical or biological processes operating in a depositional environment

metamorphic rocks _______

are formed under conditions of high temperatures and pressures