Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
107 Cards in this Set
- Front
- Back
|
Strike-Slip Fault
|
Horizontal Movement along a fault plane forms a SSF. They create linear rift valleys instead of cliffs. EX- San Andreas fault in Cali
|
|
|
Horst
|
Upward faulted blocks
|
|
|
Graben
|
Downward faulted blocks
|
|
|
Orogenesis(Mountain Building)
|
Can occur through the capture of migrating exotic terranes, adding by accretion to the continental margins, or the intrusion of granitic magmas to form plutons.
|
|
|
Uplift
|
Final part of an orogenic cycle
|
|
|
Relative Time Scales
|
what happened in what order
-largely based on the relative positions of rock strata above or below eachother |
|
|
Absolute Time Scale
|
Actual number of years before the present
-largely determined through radiometric dating |
|
|
Holocene
|
the youngest epoch in the geologic time scale. From the present to about 11,000 years before the present.
|
|
|
Anthopocene
|
A proposed new human epoch based on humans effects on the world. Where would it start?
|
|
|
Uniformitarianism
|
The same physical processes active in the environment today have been operating through geologic time.
|
|
|
Inner Core
|
thought to be solid iron that is kept solid despite the high temp due to the enormous pressure. 13.5 g/cm^3
|
|
|
Outer Core
|
Molten, metalic iron with an estimated density of 10.7 g/cm^3
|
|
|
What generates earths magnetic field?
|
The outer core(90%); Earths magnetic field occasionally reverses, with an average period of 500,000 years. The last one was 790,000 years ago.
|
|
|
Earth's Mantle
|
Together the upper and lower mantle constitute 80% of Earth's total volume.
|
|
|
Glutenberg Discontinuity
|
The transition zone between the lower mantle and the outer core
|
|
|
What is the mantle thought to be primarily composed of?
|
Magnesium and Silicates
|
|
|
Upper Mantle
|
3 main parts- the upper mantle, asthenosphere, and the uppermost mantle.
|
|
|
Asthenosphere
|
The plastic layer; occurs between 70 km and 250km below the surface.
|
|
|
Lithosphere
|
Includes the crust and the uppermost mantle. Runs from the the surface to approx 70km in depth.
|
|
|
Mohorovičić Discontinuity
|
Separates the crust and uppermost mantle. A depth where sharp contrasts of materials and densities occur.
|
|
|
Continental Crust
|
largely granite; high in silica, aluminummpotassium, calcium, and sodium; low density 2.7 g/cm^3
|
|
|
Oceanic Crust
|
mostly basalt; High in silica, magnesium, and iron; Denser than CC- 3.0 g/cm^3
|
|
|
Differences in densities causes
|
Denser oceanic material to be forced below the more buoyant continental crust
|
|
|
Isostatic Adjustment
|
The weight of the crust depress the layers beneath it. The greater the weight, the more depression occurs. Mountains and the asthenosphere, which rebounds when the weight is removed. The uplift of the recovery is termed isostatic rebound.
|
|
|
Hydrologic Cycle
|
Circulation of water, water vapor, ice and energy throughout Earth-atmosphere-ocean environment. Rearranges Earth materials through erosion, transportation, and deposition.
|
|
|
Rock Cycle
|
The production of 3 basic rock types, igneous, sedimentary, and metamorphic, through materials to the mantle, creating movement and deformation of the crust.
|
|
|
Tectonic Cycle
|
The movement of heat energy and new materials to the surface and the recycling of old materials to the mantle, creating movement and deformation of the crust.
|
|
|
Facts About the Rock Cycle
|
-8 elements compose 99% of crust; oxygen and silicon account for 74.3%
|
|
|
Minerals
|
Inorganic, or non living, natural compounds having a specific chemical formula and possessing a crystalline structure.
|
|
|
Mineralogy
|
The study of the composition, properties and classification of minerals
|
|
|
Igneous Rocks
|
-A rock that has a solidified and crystallized from a molten state; EX- granite, basalt, rhyolite
-Formed from magma; -Comprise 90% of crust. Frequently covered with sedimentary rocks. |
|
|
Plutons
|
Any intrusive igneous rock body, regardless of size or shape, that invaded layers of crustal rocks. Batholith- Sierra Nevada
|
|
|
Sedimentary Rocks
|
Formed through lithification, which is the process of cementation, compaction, and a hardening of sediments; formed from fragments of existing rock organic matter (Sandstone, shale, limestone, coal)
Stratigraphy looks at the layered strata of sedimentary rocks. |
|
|
Clastic Sedimentary Rocks
|
made of weathered and fragmented rocks that are further worn in transport.
|
|
|
Chemical Sedimentary Rocks
|
Made from dissolved minerals, transported in solution and chemically precipitated from solution. These rocks are vulnerable to chemical weathering.
|
|
|
Metamorphic Rocks
|
rocks that have been transformed through chemical changes due to pressure and increased temperature
-generally more compact and harder than the original rocks |
|
|
Why do earthquakes occur
|
Stress builds a strain in rocks until friction is overcome and the sides along plate boundaries or fault lines break loose and lurch into new positions.
|
|
|
Focus
|
The subsurface area along a fault plane where the motion of seismic waves is initiated
|
|
|
Epicenter
|
the area at the surface directly above the focus
|
|
|
Aftershock
|
energy release of an earthquake after the main shock
|
|
|
Foreshock
|
earthquake preceding the main shock.
|
|
|
Moment Magnitude Scale
|
in use since 1993; more accurate than the richter scale; takes into account the amount of fault slippage, size of ruptured surface area, and the nature of faulted materials
|
|
|
P(Primary)
|
Waves are the compression waves of earthquakes
|
|
|
S(Shear)
|
waves are the transverse waves that shake perpendicularly to the direction of propogation
|
|
|
Volcano
|
forms at the end of a central vent that rises from the asthenospehere and upper mantle through the crust
|
|
|
Crater
|
circular surface depression of a volcano at or near the summit
|
|
|
Lava
|
molten rock and clastic materials violently ejected during an eruption
|
|
|
Pyroclastics
|
rock and clastic materials violently ejected during an eruption
|
|
|
Cinder Cone
|
small, cone shaped hill with a truncated top formed during moderately explosive eruptions
|
|
|
Caldera
|
large basic shaped depression that forms when summit material collapses inward after an eruption o loss of magma
|
|
|
Aa Lava
|
basaltic lava that is rough and has jagged edges; this lava occurs due to lost gasses and slow flows
|
|
|
Pahoehoe Lava
|
More fluid that aa lava; develops a thin crust and folded appearance as it flows
|
|
|
Settings of Volcanic Activity
|
Along subduction boundaries at continental plate oceanic plate convergences; along sea floor and areas of rifting on continental plates; hot spots
|
|
|
Effusive Eruptions
|
Relatively gentle eruptions that produce enormous volumes of lava; Low viscosity magma that is very fluid; Gases escape easily and explosions are small
|
|
|
Explosive Eruptions
|
Usually occurs in inland areas near subduction zones; Magma thicker with higher viscosity
|
|
|
Denudation
|
processes that wear away or rearrange landforms
-processes include weathering, mass movement, erosion, transportation, and deposition |
|
|
Dynamic Equilibrium Model
|
hypothesizes a balance among force, form, and process
|
|
|
Geomorphic Threshold
|
point at which there is enough energy to overcome resistance against movement
|
|
|
System Sequence Through Time:
|
1. equilibrium stability
2. destabilizing event 3. period of adjustment 4. development of a new and different condition of equilibrium stability |
|
|
Angle Of Response
|
angle of a slope where there is a balance between the driving and resisting forces. Often b/w 30 and 37 degrees
|
|
|
Waxing Slope
|
increasing steepness of slopes near the top
-free face- steep scarp or cliff; often the result of resistant rock strata |
|
|
Debris Slope
|
slope of eroded material from above. transitions into a waning slope(concave along the base of the slope)
|
|
|
Weathering Process
|
Are both physical and chemical, that act in synergy; does not transport materials it generates for erosion and transport water, wind, waves, and ice as acting under the influence of gravity
|
|
|
Physical and Chemical Weathering Areas
|
P- Drier cooler climates
C- wetter warmer climates |
|
|
Physical Weathering Process
|
Mechanical Weathering; Breaks down rock without chemical alteration
|
|
|
Frost Action
|
When water freezes, its colmn can expand as much as 9%. Results in freeze thaw action; breaks apart rock; important in humid microthermal climates and polar climates
|
|
|
Taus Slope
|
Poorly sorted, cone shapes deposit of debris at the base of a steep slope
|
|
|
Crystallization
|
moisture is drawn to rock surfaces in dry weather. Dissolved minerals in the water can grow crystals which physically break apart rock
|
|
|
Pressure Release Jointing
|
Granite Plutons that have burial pressure removed and respond with physical heaves. Layers of rock sheeting off the structure in a process known as sheeting. Creates arch shaped dome features
|
|
|
Chem Weathering
|
In decomp, or chem change, of minerals in rock. Involved reactions between air, water, and minerals in rock. Hastened in presence of water and is important in warm and wet climates
|
|
|
Hydration
|
combination with water. water becomes part of the chemical composition of a mineral
-some minerals expand when they hydrate stressing the rock |
|
|
Hydrolisis
|
decomposition process that breaks down minerals in rock
-crystal networks break down causing the rock to fail |
|
|
Oxidation
|
when metallic elements combine with oxygen to form oxides. RUST
|
|
|
carbonation and solution
|
the weathering due to dissolving minerals into solution. water is the universal solvent
|
|
|
Karst Topography
|
Limestone landscapes Very susceptible to chemical weathering
|
|
|
Mass Movement Processes
|
applies to any unit movement of a body of material; driving force is gravity; occurs on slopes, the balance of which occurs at a steepness called the angle of response
|
|
|
4 classes of movement
|
fall, slide, flow, creep
|
|
|
Falls and avalanches
|
rockfalls are volumes of rock through the air and strokes a surface
|
|
|
translational slides
|
involves movement along a planar surface roughly parallel to the angle of the slope with no rotation
|
|
|
rotational slides
|
occurs when surface material moves along a concave surface
|
|
|
Flows(earthflows/mudflows)
|
when the moisture content of moving material is high
|
|
|
Creep
|
persistent, gradual mass movement of soil. occurs when frequently in areas with freeze-that cycles
|
|
|
Scarification
|
human induced mass movements; mining is an example of how humans impact material movement
|
|
|
Hydrology
|
study of water, its circulation, distribution, and properties
|
|
|
fluvial processes
|
stream related processes
|
|
|
fluvial erosion
|
weathered sediment is moved to new locations
|
|
|
deposition
|
process of material settling out from movement
|
|
|
alluvium
|
term for the clay, silt, sand, gravel, or other material deposited by water on a floodplain, delta, or streambed
|
|
|
drainage divide
|
ridges that define drainage basins
|
|
|
watershed
|
the catchment(water receiving) area of the drainage basin
|
|
|
sheetflow
|
initial downslope movement of water in a thin film
|
|
|
interfluves
|
high ground that separates valleys from eachother and directs sheetflow
|
|
|
internal drainage
|
streams that drain into basins that lose water through evap or subsurface flow(great salt lake)
|
|
|
drainage density
|
determined by dividing the total length of al stream channels in the basin by the area of the basin. high in humid climates and low in desert climates
|
|
|
drainage patterns
|
the arrangement of channels in an area
|
|
|
Dendritic Drainage
|
branching drainage like the vein patterns in leaves. energy is expended efficiently
|
|
|
Trellis Drainage
|
characteristic of dipping of folded topography;
|
|
|
radial drainage pattern
|
results from streams flowing off a central peak or dome
|
|
|
parallel drainage
|
associated with steep slopes
|
|
|
Rectangular Drainage
|
formed by a faulted and jointed landscape, which directs stream courses in patterns of right angle turns
|
|
|
annular drainage
|
produced by structural domes with conodentric patterns of rock strata guiding steam courses
|
|
|
deranged drainage pattern
|
no clear geometry in the drainage and no true stream valley pattern
|
|
|
exotic streams
|
streams where discharge decreses with distance (Nile)
|
|
|
Stream Erosion
|
turbulence and abrasive actions shape the landscapes through which streams flow
|
|
|
Stream transport
|
defined through the ability to move particles (competence) and capacity (the total possible transport load)
|
|
|
alluvial terraces
|
topographic steps of a fluvial landscape due to the increased entrenchment of rejuvenated streams
|
|
|
alluvial fan
|
fan shaped alluvial land form at the mouth of a canyon, generally arid landscapes
|
