Geology 1040 Fin

Movement in the Earth's crust after a sudden release of energy.

The point of origin of an earthquake on the surface of the Earth.

The point of origin of an earthquake within the Earth's crust.

A rupture in the lithosphere that contains the earthquake's focus.

Seismic waves that travel through the crust, mantle, and/or the core of the Earth. Primary and Secondary waves.

Seismic waves that only travel through the uppermost layer of the crust. Slow but with greater amplitude (greater surface damage). Rayleigh and Love waves.

The fastest body seismic wave that can travel through any kind of matter. Moves through compression and expansion like a slinky.

A fast body seismic wave that can only travel through solids. Moves in vertical waves, like water.

A surface seismic wave that travels in a vertical, rippling motion.

A surface seismic wave that travels in a side-to-side motion like a snake. The most damaging of seismic waves.

Small tremors that precede an earthquake.

Long-term (weeks to years) tremors that follow an earthquake.

Occurs when soil loses its strength and allows water to flow through it, creating quicksand or quickclay.

Massive waves resulting from sea-floor earthquakes, submarine landslides, volcanic eruptions, or fault movements. Unaffected by wind speed.

A method of mitigating seismic activity by decoupling a superstructure from the substructure that rests on the ground. The substructure absorbs all of the seismic waves and the superstructure above ground remains unaffected.

A method of mitigating seismic activity by dispersing energy across a wide range of frequencies. Achieved by buildings that taper, such as a pyramid or tower.

A method of mitigating seismic activity by absorbing resonant portions of a wave's frequency. Buildings move opposite to the resonance, reducing damage.

Earthquakes can be predicted long-term (years) but not short term (hours to weeks).

The process of mountain building consisting of the uplift of crust and the erosion (or exhumation) of peaks.

A force applied across a unit area.

Stress where an object is squeezed from two opposing directions.

Stress where an object is pulled apart from two opposing directions.

Stress where two objects slide past each other.

Stress where an object undergoes compression from all directions.

The deformation a rock has after being stressed.

Strain where hard, low-temperature rocks fracture and break. Fast rate of deformation.

Strain where soft, high-temperature rocks bend and fold like plastic. Slow rate of deformation.

10-15 km below Earth's surface.

Deformation where a rock changes its location.

Deformation where a rock changes its orientation or tilt.

Deformation where a rock changes its shape.

A form of brittle deformation where parallel fractures break rock apart without any offset. Forms from tensile stress.

A form of brittle deformation where joints are filled with minerals (quartz or calcite) that push the joints apart and further break rock apart.

A form of brittle deformation where planar fractures displace mass amounts of rock.

The side of a fault that overhangs or is positioned above the foot wall. Undergoes displacement during seismic activity. Intersects the surface of the Earth at <90°.

The side of a fault that is not displaced. Intersects the surface of the earth at >90°.

The hanging wall moves down relative to the foot wall due to extension (tension). Creates a dip.

The hanging wall moves up relative to the foot wall due to compression. Sharp slope.

The hanging wall moves up relative to the foot wall due to compression. Gentle slope. D

The hanging wall moves parallel to the fault plane; up or down.

The hanging wall moves parallel to the fault line; left or right.

The hanging wall moves in two directions; up and left, down and right, etc.

Rock fragments along a fault.

Pulverized, powdered rock.

Linear grooves along a fault.

Where ductile deformation (folding) is at its greatest curvature. Always perpendicular to the compression forces.

Less curved sections of folded rock layers.

Folded rock that arches upwards. A shape. Older rocks are in the center.

Folded rock that dips downwards. U shape. Younger rocks are in the center.

Folded rock formed from anticlines from all sides. Older rocks are in the center.

Folded rock formed from synclines from all sides. Younger rocks are in the center.

The balance between buoyancy and erosion of continental crust. Thicker parts of the crust are uplifted higher but also plunge further into the mantle.

The idea that geologic formations are created and repeated in uniform, predictable events. Processes seen today are the same as processes that occurred before. Developed by James Hutton.

"The Grand Canyon was formed by the gradual erosion of rock over millions of years."

The idea that geologic formations are created after singular major events.

"The Grand Canyon was formed by a singular massive flood."

A method of dating rocks based upon the order of formation. A qualitative method that determines older vs younger relationships.

A method of dating rocks based upon the years since its formation or metamorphosis. A quantitative method that only works on igneous and metamorphic rocks.

Sediments are deposited in straight, horizontal beds under regular conditions.

Older rock beds are found underneath younger rock beds.

Strata (rock layers) form horizontally across the Earth's surface. Allows separated strata to be connected.

Younger features pass through older features. Faults, intrusions, erosion, etc must be younger than the material that is faulted, intruded, or eroded.

Igneous intrusions bake the rock it invades and thus must be younger than the rock it invades.

Rock fragments intruding another material must always be older than the material enclosing it. Older rock weathers and becomes enclosed by younger rock.

A layer of magma that covers older layers and does not contain inclusions.

An igneous intrusion that invades layers of older rock. Contains inclusions.

All of the rock layers in which a particular species' fossil can be found.

Specific species that are diagnostic to a particular time period.

A time gap in the rock record caused by erosion or nondeposition.

Ancient rocks become folded, erode, and young sediments are deposited on top. Ancient sediments are no longer layered horizontally whereas the young sediments are.

Ancient igneous or metamorphic rocks have eroded and sedimentary rocks have been deposited on top. All beds are parallel.

Ancient sedimentary rock layers are eroded or have a pause in deposition, and much younger sedimentary rock layers are deposited above. Very short time gap.

Elements that have varying numbers of neutrons that affect the stability of the atom.

Isotopes that do not change over time.

Isotopes that spontaneously, radioactively decay over time.

The process of a radioactive parent isotope decaying and producing a stable daughter isotope.

A known, fixed rate at which the parent isotope decays 50% into the daughter isotope.

Carbon-14

Uranium, Potassium, Rubidium, Samarium.

The temperature at which an igneous rock has solidified or a metamorphic rock has metamorphosed, locking in its elements. Radioactive elements begin to decay after temperature is reached.

4.57 Ga / 4.57 billion years

The study and connection of different rock layers across the surface of the Earth to create a global geologic column.

Hundreds of millions to billions of years.

65 to hundreds of millions of years.

2 to 70 million years.

Less than 22 million years.

4.57 - 3.8 Ga

First Eon of Earth's history. "Hell-like", the Earth was still forming. Its mantle and core cooled and differentiated and much of the surface was covered in magma oceans.

3.85 - 2.5 Ga

The second Eon of Earth's history. Earth's crust solidified and plate tectonics began to occur. Oceans filled with water. Life first developed in the form of thermophilic bacteria deep underwater.

3.2 Ga / 3.2 billion years ago, in the Archean Eon.

Alternating layers of cyanobacteria and sediments. Oldest extant (still living) life on Earth.

2.5 Ga - 542 Ma.

The third eon of Earth's history. Supercontinents assembled and rifted and early life began to develop.

~2.7 Ga / in the Proterozoic Eon.

Photosynthetic organisms oxygenated Earth's atmosphere between 2.4 and 1.8 Ga / in the Proterozoic Eon.

~750 Ma / in the Proterozoic Eon.

A supercontinent of the Proterozoic Eon that formed ~1 Ga and rifted ~700 Ma. Precursor to Pangaea.

A major shift in Earth's climate in the late Proterozoic that covered the continents in glaciers and froze the oceans. Ended with volcanic activity.

542 Ma to Present Day

The fourth eon of Earth's history. Defined by visible life and the widespread diversification of life in Earth's oceans and landmasses. Carbonate and skeletal material enhance the preservation of these organisms.

A shallow ocean that forms above lowland continental crust.