Geological Processes

weathering

physical or chemical breakdown of rocks into smaller pieces

mechanical weather

• also called physical weathering

• type of weathering

• where no chemical changes happen to the rock, and is due to water, wind, or ice

chemical weathering

• type of weathering

• causes a rock to dissolve and form new substances due to chemicals like acid rain

biological weathering

• type of weathering

• disintegration of rocks that are due to the actions of plants, animals, or people

abrasion

• type of mechanical weathering

• process by which clasts are broken through direct collision with other clasts

• gravity abrasion, current abrasion, and wind abrasion

frost wedging

• type of mechanical weathering

• collective term for several mechanical weathering processes induced by stresses created by the freezing of water to ice

salt-crystal growth

• tyep of mechanical weathering

• when salt solution seeps into chalks and evaporates

• leaves salt crystals behind to expand as they’re heated up

types of chemical weathering

reaction with water, oxygen, acid and organisms

erosion

movement of sediment from broken rocks

agents of erosion

water, wind, ice, and gravity

vertical erosion

• type of erosion

• happens when gradient is too steep

• creates a v-shaped valley

horizontal erosion

• happens with a wide and broad river valley

• causes current to be weaker

• causes volume of water to be greater

deposition

• dropping of sediments in a new place

• happens at the end of a river process

sedimentation

• tendency for particles in suspension to settle out of the flow

causes of sedimentationg

gravity, centrifugal acceleration, electromagnetism

compaction

• type of sedimentation

• happens when more layers pile up and press down into layers

cementation

• type of sedimentation

• when salt crystal glues the layers together and form sedimentary rock mass

folding

deformation or buckling of a rock layer that was once horizontal

anticline

folds that arch upwards to form a ridge

synclines

olds that arch downwards to form a trough

monocline

simple bend in the rock layers so that they are no longer horizontal

open (symmetrical) fold

• type of fold

• when the axial fold is vertical

asymmetrical fold

• type of fold

• when the axial fold in inclined

overturned fold

• type of fold

• when it has a highly inclined axial plane

recumbent fold

• type of fold

• when it has ane ssentially horizontal axial plane

isodinal fold

• type of fold

• has limbs that are essentially parallel

faulting

• the result of the movement of the earth’s plate

• result of the movement of the earth’s plate

• occurs when there is stress along a weak point in the earth’s crust

normal fault

• type of fault

• happens when there is stress at a divergent boundary

reverse fault

• type of fault

• happens when the rock is forced upwards as it is squeezed

strike-slip fault

• type of fault

• happens when two plates slide past one another

• has two types: right-lateral strike-slip, and left-lateral strike-slip

divergent plate boundary

• type of boundary

• happens when a plate boundary moves or extends in different directions

convergent

• type of boundary

• happens when plates come clsoe together and compress

ocean-to-continent convergence

• undergoes a process called subduction

• occurs along oceanic trenches

• type of convergent boundary

oceanic-to-oceanic plate boundary

• occurs when two oceanic plates converge and causes the older, denser plate to subduct into the mantle

• type of convergent boundary

continental-to-continental convergence

• creates intense folding and faulting rather than volcanic activity

• type of convergent boundary

transform plate boundary

• type of plate boundary

• happenns when plates grind past each other

stress

refers to force applied to an obejct

tension stress

• type of stress applicable to normal faults

compression stress

• type of stress applicable to reverse faults

shearing stress

• type of stress applicable to strike-slip faults

strain

refers to a change in shape caused by the application of stress

elastic strain

• recoverable strain

• also known as deformation

plastic strain

• permanent strain

• also known as ductile deformation

brittle strain

• fracture strain

earthquakes

sudden ground movement caused by the sudden release of energy stored in rocks

seismic waves

energy that creates an earthquake

crest

high point of a seismic wave

trough

low point of a seismic wave

aplitude

crest to centerline

wavelength

trough to trough/crest to crest

seismology

• study of seismic waves

• seismologists use seismic waves to learn about earthquakes and the earth’s interior

body waves

• has two types and travels through the earth’s interior

p-waves

• type of body wave

• can travel through solids, liquids, and gases

s-waves

• type of body wave

• can only travel through solids

surface waves

• travels along the ground and is the slowest

• produces rolling motions

seismographs

• produces a graph-like representation of seismic waves

• recorded onto a seismogram

seismometer

records ground motions using electronic motion detectors

Mercalli Intensity Scale

• oldest scale to measure earthquakes

• focuses on qualitative information

• based on visual damage

Richter Magnitude Scale

• developed by Charles Richter in 1935

• uses a seismometer to measure the magnitude of the largest jold of energy released by an earthquake

Moment Magnitude Scale

measures the tota

Pangaea

• was once a supercontinent

• all continents were combined into one, 250 million