Exam 2 Flashcards
By the time sediments reach the ocean basins, they have become:
well rounded and well sorted
which mineral is commonly used to determine a metamorphic P-T path?
garnet
Which of the following tectonic settings will be coolest at 30-KM depth?
stable continental lithosphere
Which of the following rocks represents the highest metamorphic grade?
Gneiss
Which is the type of metamorphism with the highest pressure and lowest temperature from these choices…
shock
Reverse faults form in response to _____ forces
compressive
The study of the layers in sedimentary rocks is known as:
stratigraphy
Phyllite is a rock of which type of metamorphism:
low grade
The dip of a unit represents the:
angle at which the bed inclines from the horizontal
What type of material undergoes smooth, continuous plastic deformation?
Ductile
An anticline is a sequence of folded rocks with the youngest rocks on the inside of the fold
False
The difference between a fault and a joint is that _________.
Rocks on either side of a fault have moved, whereas rocks on either side of a joint have remained stationary
Which of the following statements about rock deformation is false?
Rocks under low surrounding pressure are more likely to deform ductilely than rocks under high surrounding pressure.
The Principle of Superposition states that ______
undisturbed sedimentary layers get progressively younger
The half life of a radioactive isotope is _______
the time it takes of half atoms to decay
Radiometric dating is possible if a rock contains a measurable amount of ________
both parent and daughter atoms
Which of the following is the largest division of geologic time?
Eon
Under intense pressure and high temperature, hydrogen atoms combine to form helium. This process is called:
nuclear fusion
The hypothesis that explains the formation of the solar system is referred to as_______
nebular hypothesis
What caused dust and condensing material to accrete into planetesimals?
gravitational attractions
The 4 inner planets are
small, rocky, and relatively lacking in volatile elements
What mountain chain runs along the eastern margin of North America?
The Appalachians
What are the five Tectonic Ages?
Archaean, Proterozoic, Paleozoic, Mesozoic, Cenozoic
What is meant by the tectonic age of a region?
The youngest major deformation event in the region
Describe the Wilson cycle order
Continental rifting, continent-continent collision, subduction, rifting
Cratonic keels are ______
thicker under continents
What is metasomatism?
A change in the bulk composition of a rock during metamorphism
What type of metamorphism is caused by igneous intrusions?
Contact Metamorphism
Which of the following processes will cause metamorphism?
Increase in temperature and pressure plus an interaction with hydrothermal fluids
At what type of plate tectonic boundary would you expect shearing forces to occur?
Transform
What determines whether a rock deforms in a brittle fashion versus a ductile fashion?
Temperature, rate of deformation, rock type
Which of the following is used by geologists to determine the relative ages in a rock sequence?
cross-cutting relationships, fossils, stratigraphy
Which is the most likely parent rock of marble?
Limestone
Purely tensional stresses associated with a _________ plate boundary will generate a _______ fault.
Divergent; normal
When considering the effects of faulting on the lithosphere, it is clear that normal faults serve to effectively:
Thin and extend the crust
When did the Mesozoic era begin?
250 million years ago
Which planet is closest in size to earth?
Venus
Current evidence indicates that the Moon was produced by:
The collision of a Mars-sized body with Earth
Which list places the four inner planets in order of increasing distance from the Sun?
Mercury, Venus, Earth, Mars
Cratons are made up of
platforms and shields
The study of geobiology is defined as _________.
The study of how organisms influence and are influenced by Earth’s environment.
The radiation of life at the beginning of the Phanerozoic is known as the _______
Cambrian Explosion
Organisms that gain energy from feeding directly or indirectly on “producers” are referred to as ___________.
heterotrophs
The pathway through which a chemical element or molecule moves between the biologic and environmental components of an ecosystem is called the _______.
biogeochemical cycle
In which geologic environment would you expect to find thermophiles?
mid-ocean ridge
Sedimentary features that form from the interaction of microbes with their environment are called __________.
Stromatolites
Photosynthesis arose in a group of bacteria knows as __________.
cyanobacteria
Which is older, the intrusion or fault?
intrusion
which principle do you use to identify the oldest rocks unit?
superposition
