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