Metamorphism
Heat, pressure, and hydrothermal fluids are the three main agents of this rock-altering process.
Metamorphism
Stress is the force applied to a rock, while this term describes the actual change in shape or deformation the rock experiences in response.
Strain
According to elastic rebound theory, earthquakes are caused by the sudden release of this specific type of accumulated strain.
elastic strain
This principle states that in an undisturbed sequence of sedimentary rocks, the oldest layer is on the bottom and the youngest is on top.
Principle of Superposition
In radiometric dating, the original unstable isotope is called the parent, and the stable product it decays into is called this.
daughter isotope
This parent rock (or protolith) is pure quartz sandstone before it undergoes metamorphism.
Quartzite
Under high temperature and high confining pressure deep in the crust, rocks are more likely to deform in this flowing manner rather than fracturing.
ductile deformation
This seismic wave arrives first at a seismograph station, but usually causes the least amount of ground shaking and damage.
P-wave (Primary wave)
This general term refers to a buried erosional surface representing a gap in the geologic rock record.
an unconformity
This is the time it takes for exactly 50% of a radioactive parent isotope to decay into its stable product.
half-life
In order of increasing metamorphic grade, the sequence of foliated rocks is slate, phyllite, this rock, and finally gneiss.
Schist
This type of fault, where the hanging wall moves down relative to the footwall, is most likely to form at divergent plate boundaries where tensional stress pulls the crust apart.
normal fault
This secondary earthquake hazard occurs when water-saturated, unconsolidated sediments lose their strength during shaking and behave like a fluid.
liquefaction
If a fault breaks through a layer of sandstone, the fault must be younger than the sandstone according to this geologic principle.
Principle of Cross-Cutting Relationships
If a mineral crystal contains 25% parent isotope and 75% daughter isotope, this exact number of half-lives has passed.
2
This type of metamorphism occurs when rock is baked by an intruding magma body, typically lacking the directed pressure needed to create foliation.
contact metamorphism
This type of fold is characterized by an upward "A-shaped" arch with the oldest rocks located in the center.
an anticline
Unlike dip-slip faults, this type of fault on the seafloor is least likely to cause a tsunami because it does not displace water vertically.
strike-slip fault
This specific type of unconformity features tilted or folded sedimentary rocks sitting directly below flat-lying sedimentary rocks.
angular unconformity
This durable mineral is incredibly useful for dating ancient rocks because it naturally traps Uranium but rejects Lead when it first crystallizes from magma.
zircon
These two factors together ultimately dictate the specific mineral assemblage a metamorphic rock will end up with.
the protolith (original composition) and the pressure/temperature conditions (metamorphic grade)
Compressional stress at a convergent boundary typically produces these types of faults, where the hanging wall is pushed up and over the footwall.
thrust (or reverse) faults?
As seismic waves travel from hard, solid crystalline bedrock into weak, unconsolidated sediments, the amplitude of the ground shaking will do this.
increase (or grow stronger)
To form a nonconformity, igneous or metamorphic rock must first form deep underground, followed by this crucial surface process to expose it before new sediments can be deposited on top.
erosion (or uplift and erosion)
The Phanerozoic Eon is divided into these three major eras, which translates to "ancient life," "middle life," and "recent life."
Paleozoic, Mesozoic, and Cenozoic