Geology 101 Test 2-Knapp South Carolina
Relative dating
(fossils, structure, cross-cutting relationships): how old a rock is compared to surrounding rocks uses cross-cutting relationships
The Wilson Cycle
1. Continental rifting 2. continent-continent collision 3. subduction 4. continental rifting
In the Solar System a planet is a celestial body that
1.) is in orbit around the Sun, 2.) has sufficient mass so that it assumes a hydrostatic equilibrium (nearly round) shape, and 3.) has "cleared the neighborhood" around its orbit. -must have all or it is a dwarf
When did the Mesozoic era begin? 65 million years ago 543 million years ago 250 million years ago 2.5 billion years ago
250 million years ago
In which geologic environment would you expect to find thermophiles? A) a mid-ocean ridge B) a continental shelf C) an abyssal plain D) a river
A. a mid-ocean ridge
What caused dust and condensing material to accrete into planetesimals? A. gravitational attraction and collisions B. heating of gases C. nuclear fusion D. rotation of the proto-sun
A. gravitational attraction and collisions
absolute age
Absolute age of a geologic event in the rock record is the number of years that has elapsed between the event and the present day
The study of geobiology is defined as _________. A) the study of ancient life forms on Earth B) the study of how organisms influence and are influenced by Earth's environment C) the study of the Earth's environmental changes throughout time D) the study of the organisms lost during mass extinction events
B) the study of how organisms influence and are influenced by Earth's
Cratons are made up of: A. orogens and platforms B. platforms and shields C. orogens and shields D. orogens, platforms, and shields
B. platforms and shields
Radiometric dating is possible if a rock contains a measurable amount of ___________. A) daughter atoms B) parent atoms C) both daughter and parent atoms D) either daughter or parent atoms
C) both daughter and parent atoms
Which of the following statements about rock deformation is false? a. Deep crustal rocks are more likely to deform ductilely than shallow crustal rocks. b. Hotter rocks are more likely to deform ductilely than cooler rocks. c. Rocks under low surrounding pressure are more likely to deform ductilely than rocks under high surrounding pressure. d. Sedimentary rocks are more deformable than igneous rocks.
C. Rocks under low surrounding pressure are more likely to deform ductilely than rocks under high surrounding pressure.
The difference between a fault and a joint is that _________. a. faults cut through more than one layer of rock, whereas joints cut through only one layer. b. faults cut through bedrock, whereas joints cut only the upper sedimentary layers c. rocks on either side of a fault have moved, whereas rocks on either side of a joint have remained stationary d. faults form straight lines in map view, whereas joints form zigzag lines
C. c. rocks on either side of a fault have moved, whereas rocks on either side of a joint have remained stationary
Purely tensional stresses associated with a _________ plate boundary will generate a _______ fault. A. convergent; strike-slip B. convergent; normal C. divergent; reverse D. divergent; normal
C. divergent; reverse
When did the faulting occur? Between the deposition of A & B Between the deposition of C & D Between the deposition of B & C Between the deposition of D & E __________A _______B \___C ___ \D
C.) Between the deposition of B & C
The hypothesis that explains the formation of the solar system is referred to as _____. A.) Big Bang hypothesis B.) origin hypothesis C.) nebular hypothesis D.) planetesimal hypothesis
C.) nebular hypothesis
The radiation of life at the beginning of the Phanerozoic is known as the _______. a. Cambrian adaptation b. Cambrian explosion c. Precambrian radiation d. Precambrian adaptation
Cambrian explosion
Cratonic keels are __________. A) thinner under continents than oceans B) of even thickness everywhere C) thinnest under cratons D) thicker under continents than oceans
D) thicker under continents than oceans
Which list places the four inner planets in order of increasing distance from the Sun? A. Mars, Mercury, Earth, Venus B. Venus, Mercury, Earth, Mars C. Mercury, Mars, Venus, Earth D. Mercury, Venus, Earth, Mars
D. Mercury, Venus, Earth, Mars
Current evidence indicates that the Moon was produced by: A. simultaneous accretion. B. the eruption of magma into space. C. Earth capturing an asteroid. D. The collision of a Mars-sized body with Earth.
D. The collision of a Mars-sized body with Earth.
What is the relative timing between faulting and intrusion of the granite? A. Faulting occurred after the intrusion of the granite B. Faulting occurred before the intrusion of the granite C. Faulting and intrusion of the granite occurred at the same time D. The relative timing between faulting and intrusion of the granite cannot be determined from the information provided
D. The relative timing between faulting and intrusion of the granite cannot be determined from the information provided
Organisms that gain energy from feeding directly or indirectly on "producers" are referred to as ___________. A) autotrophs B) chemotrophs C) phototrophs D) heterotrophs
D. heterotrophs
When considering the effects of faulting on the lithosphere, it is clear that normal faults serve to effectively: A. shorten and thicken the crust. B. thin and shorten the crust. C. thin and extend the crust. D. shorten and thin the crust.
D. shorten and thin the crust.
folds
Folds imply that an original planar structure, such as a sedimentary bed, has been bent. Most typical in mountain belts.
joints
Fractures in rocks along which there has been no appreciable displacement Rocks on either side of a fault have moved, whereas rocks on either side of a joint have remained stationary
which mineral is commonly used to detriment a metamorphic P-T path? Calcite Garnet Muscovite Quartz
Garnet
Which of the following rocks represents the highest metamorphic grade? Gneiss Phyllite Schist Slate
Gneiss beer=good high=good
Which of the following sequences describes the Wilson cycle? I. continent-continent collision II. continental rifting III. sea-floor spreading IV. subduction I - IV -II -III II - III - IV - I II - I - IV - II IV - II - III - IV
II - I - IV - II
Which is the type of metamorphism with the highest pressure and lowest temperature from the choices below: Shock Burial Regional Contact
Shock
What is metasomatism? A. a change in the bulk composition of a rock during metamorphism B. metamorphism caused by nearby magmatic intrusions C. metamorphism caused by tectonic movements along faults D. the parallel alignment of minerals in a metamorphic rock
a change in the bulk composition of a rock during metamorphism
strike
a line at right angles to the dip direction example: on rooftop-the line at the top where the roof descends from
sequence
a series of sedimentary beds bounded by unconformities
The dip of a unit represents the: a. Angle at which the bed inclines from the horizontal b. Direction of intersection of the rock layer and a horizontal surface c. part of the unit that has been eroded d. tilt of the rock unit before deformation
a. Angle at which the bed inclines from the horizontal
Absolute geochronology
adds #s to the stratigraphic column based on fossils based on regular radioactive decay of some chemical elements
Which of the following is used by geologists to determine the relative ages in a rock sequence? a. Cross-cutting relations b. Fossils c. Stratigraphy d. all of the above
all of the above
Which of the following processes will cause metamorphism? a. an increase in pressure b. an increase in temperature c. interaction with hydrothermal fluids d. all of the above
all of the above
dip
angle of steepest descent of the bed from the horizontal example: on rooftop-angle of roof, the part that goes down, touches gutter dip=go down, duh
The horizontal line labeled X-X' is a (an) A) angular unconformity B) contour C) cross-bed D) fault _________A__________ ________B____________ X__________________X / / /
angular conformity
upfolds or arches of layered rocks are called
anticlines a sequence of folded rocks with the oldest rocks on the inside of the fold
strain
any change in original shape or size of an object in response to stress acting on the object
isotopes
atoms of elements with the same # of protons and varying numbers of neutrons
The half-life of a radioactive isotope is ______________. a. half the time it takes all the radioactive atoms to decay b. the time it takes for half of the radioactive atoms to decay c. half of the radioactive atom's "full-life" d. the average life-span of a stable atom
b. the time it takes for half of the radioactive atoms to decay
periods
based on types of life existing at the time
The pathway through which a chemical element or molecule moves between the biologic and environmental components of an ecosystem is called the _______. biogeochemical cycle biomicrobial cycle geometabolic cycle geosynthesis cycle
biogeochemical cycle
how continents grow: continental accretion
buoyant fragments of crust attached to continents as the result of plate motions
continental shields
central, older portions of continents aka older rocks low elevation and relatively flat
types of stress
compression-pushed together, squeeze and shorten body (causes a reverse fault) tension-pulled apart, stretch body/pull it apart (causes a normal fault) shearing-moving sideways, push two sides in opposite directions (causes a strike-slip fault)
Reverse faults form in response to ______ forces. Compressive Shearing Tensional Torsional
compressive
What type of metamorphism is caused by igneous intrusions? a.burial b.metamorphism regional metamorphism c.contact metamorphism d. shock metamorphism
contact metamorphism
Photosynthesis arose in a group of bacteria knows as __________. A) cyanobacteria B) heterobacteria C) photobacteria D) chemobacteria
cyanobacteria
The four inner planets are ________________. a. mostly hot, with heavy, dense atmospheres. b. all similar to the Earth in size, atmosphere, and density. c. larger and less dense than the outer planets. d. small, rocky, and relatively lacking in volatile elements.
d. small, rocky, and relatively lacking in volatile elements.
What is meant by the tectonic age of a region? a. the oldest rocks in the region b. the oldest major deformation event in the region c. the youngest rocks in the region d. the youngest major deformation event in the region
d. the youngest major deformation event in the region
The principle of superposition states that __________. a. a fault is younger than the rocks it cuts b. sediments are deposited as essentially horizontal layers c. the present is the key to the past d. undisturbed sedimentary layers get progressively younger from bottom to top
d. undisturbed sedimentary layers get progressively younger from bottom to top
absolute dating
dating (isotopic, tree rings, etc.): actual number of years since the rock was formed
What type of material undergoes smooth, continuous plastic deformation? A) brittle B) cataclastic C) ductile D) all of the above
ductile
Which of the following is the largest division of geologic time? Eon Epoch Era Period
eon
outcrop
exposure of the bedrock without being obscured by soil or loose sediments or boulders
An anticline is a sequence of folded rocks with the youngest rocks on the inside of the fold True False
false
faults
fractures in the earths crust resulting from the displacement of one side w/ respect to the other involves relative movement of geologic layers
how continents are modified: orogeny
general term for mountain building process folding and thrusting of rock layers often accompanied by magmatic activity
cross-cutting relationships
geometry of rock bodies that allows geologist to place rock units in relative chronological order used for relative dating!
Which of the following rocks represents the highest metamorphic grade? Gneiss Phyllite Schist Slate
gneiss
Principle of Superposition
in a sequence of undisturbed layered rocks, the oldest rocks are on the bottom
Which is older, the intrusion or the fault? intrusion fault
intrusion... it broke up the fault and you can tell its older
Principle of Original Horizontality
layered strata are deposited horizontally or nearly horizontally or nearly parallel to the Earth's surface
which is the most likely parent rock of marble? A. sandstone B. shale C. limestone D. granite
limestone
eons
longest subdivision; bases on the abundance of certain fossils
Phylite is a rock of which type of metamorphism: Low grade Intermediate grade High grade metamorphism None of the above
low grade
how continents grow: magmatic differentiation
magma transfered to continents at subduction zones
Which planet is closest in size to the Earth? Mars Venus Mercury Jupiter
mercury
eras
next to longest subdivision, maker by major changes in fossil record
Under intense pressure and high temperature, hydrogen atoms combine to form helium. This process is called _____________. convection metamorphism nuclear fission nuclear fusion
nuclear fusion
which principle did you use to identify the oldest rocks unity?
original horizontality
ductile(plastic)
permanent change in shape or size of a body that is not recovered when the stress is removed smooth, continuous plastic deformation deep crustal rocks are more likely to deform ductilely than shallow crustal rocks Hotter rocks are more likely to deform ductilely than cooler rocks.
folded mountain belts
relatively narrow zones of folded rocks with associated magmatism formed a convergent plate boundaries older example: Apps
competent rocks
rocks that deform only under great stress
incompetent rocks
rocks that deform under moderate to low stresses
Type of Unconformities: Nonconformity
sedimentary layers are deposited on older igneous rocks and metamorphic rocks
where are fossils mostly found?
sedimentary rocks "something dug up" ss
epochs
shortest subdivision; marked by differences in life forms and can vary from continent to continent
Which of the following tectonic settings will be coolest at 30-km depth? Regions of continental extension Stable continental lithosphere Volcanic arcs The temperature in all three tectonic settings above will be the same at 30-km depth
stable continental lithosphere
The study of the layers in sedimentary rock is known as _________. Stratigraphy Paleontology Sedimentation Geochronology
stratigraphy
How do rocks deform?
stress-force per unit area strain-change in shape and/or volume strength-ability to resist deformation
Sedimentary features that form from the interaction of microbes with their environment are called __________. nodules stromatolites branching columns laminations
stromatolites
unconformities
surfaces where erosion has removed rock layers aka a gap in the geologic record
downfolds or throughs are called
synclines a sequence of folded rocks with the youngest rocks on the indie of old
elastic deformation
temp. change in shape or size of body that is recovered when the stress is removed
What mountain chain runs along the eastern margin of North America? the Andes the Appalachians the Caledonides the Cordillera
the apps
strike-slip fault
the blocks move horizontally, sliding past each other results from shearing motion of fault block is parallel to the strike direction
brittles (rupture)
the body undergoes little change under the stress, until it breaks suddenly earthquakes rupture
normal fault
the rocks above the fault plane move down in relation to the rocks below the fault place, causing an extension of the section results from tension
reverse fault
the rocks above the fault plane move upward in relation to the rocks below causing a shortening of the section results from compression thrust faults are low-angle reverse faults
continental keel
the strong, cool layer of lithospheric mantle material beneath a continent carton the older=the thicker
Half life
the time required for one-half of the original number of the parent atoms to be transformed into daughter atoms
At what type of plate tectonic boundary would you expect shearing forces to occur? A. divergent B. convergent C. Transform D. none
transform
how continents are modified: Epeirogeny
vertical motions of largely flat lying rocks without faulting or significant folding
By the time sediments reach the ocean basins, they have become: angular and poorly sorted very coarse grained well rounded and well sorted all of these
well rounded and sorted
Type of Unconformities: Disconformity
younger sedimentary layers are deposited on older, horizontal layers
Type of Unconformities: Angular Unconformity
younger, sedimentary layers are deposited on older, tilted, sedimentary rocks