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
