final study guide set

earths crust

5km below surface, less than 1 percent earths volume

mantle

largest shell, 84 percent earths volume, 3 sublayers; lithosphere, asthenosphere, rigid rocks-lower mantle

outer core

controls magnetic field of earth, molten

inner core

dense mass, iron/nickle and iron/silicate

minerals

naturally occurring, inorganic, crystalline solid with definite chemical composition and atomic structure

silicates

combine oxygen and silicon, most common elements in lithosphere

oxides

elements combined with oxygen

sulfides

combination of sulfur and another element

sulfates

sulfur and oxygen

carbonates

light color minerals composed of carbon, oxygen and an element

halides

salt

native elements

gold and silver

rock

made of more than one mineral, outcrops, bedrock, regolith, petrology

the rock cycle

Processes where rocks can transition from igneous rocks to sedimentary rocks to metamorphic  rocks

igenous rock

magma, lava, pyroclastics, classified based on texture and mineral composition

magma

molten rock below the surface

lava

molten rock when it flows onto earths surface

pyroclastics

rocks formed from material ejected from volcanoes

rocks formed from magma

intrusive rocks, cool slowly, large crystals

lava rocks

extrusive rocks, cool quickly, small or no crystals visible

sedimentary rock

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* External processes cause rock disintegration
* Material transported by water as sediment
* Over time sediment builds thickness
* Pressure causes sediment to interlock
* Chemical cementation

strata

horizontal layers of sedimentary rock

lithification

turn into stone

sedimentary rock types

clastic and chemical/organic sedimentary rocks

clastic

rock composed of fragments of preexisting rocks

chemical and organic sedimentary rocks

formed by precipitation of soluble materials or complicated chemical reactions

metamorphic rock

originally igenous or sedimentary but heat and pressure changed them, rearranges crystal structure of the original rock

contact metamorphism

rock contacts magma and is rearranged

regional metamorphism

large volumes of rock are subjected to heat and pressure over long time scales

schist

metamorphic rocks with narrow foliations

gneiss

broad banded foliations

evidence for plate tectonics

Similar geologic features on different continents coasts, continents fit together, Earthquakes occur along lines, These lines correspond with locations of trenches and ridges in the seafloor, paleomagnetism, glacial evidence

paleomagnetism

iron in cooled magma orients with earths magnetic poles and provides a record of past magnetic fields, symmetry in magnetic orientation, poles have changed at least 170 times

glacial evidence for plate tectonics

permian glaciers found on 4 continents, some evidence near equator, glacial deposits coverage

evidence for plate tectonics

fit of the continents, glacial deposits far from polar regions, paleoclimatic belts, distribution of fossils, matching geologic units, paleomagnetism

types of plate boundaries

divergent, convergent and transform

divergent boundaries

plates move away from each other, midocean ridge, shallow focus earthquakes and volcanic activity, constructive, continental rift valley

convergent boundaries

collisions between plates, destructive, 3 types of collisions

oceanic-continental collision

oceanic plates are more dense so they sink, subduction occurs, forms oceanic trench and continentak mountains, earthquakes along margin, volcano formation along plates, forms metamorphic rocks

oceanic-oceanic collision

subduction results in undersea trench formation, deep shallow earthquakes, island volcanic arc

continental-continental collision

no subduction since 2 plates are buoyant, builds high mountain ranges, shallow earthquakes are common

transform boundaries

2 boundaries slip past each other laterally, transform faults, neither creates nor destorys crust, produce shallow focus earthquakes

extrusive volcano

occur on earths surface often shortneded to volcanism

intrusive volcano

occurs below surface, plutonic activity

shield volcanoes

layer upon layer of solidified lava flows, little pyroclastic material

composite volcano

emits higher silica lavas, form symmetric steep sided volcanoes, pyroclastics from explosive lava flows alternate with nonexplosive flows, pyroclastic flows produce steep slopes and lava holds it together

lava domes

masses of very viscous lava that doesnt flow far, lava bulges from the vent, dome grows by expansion from below and lava within, some form inside composite volcanoes

ciner cones

smallest volcanic mountains, basaltic magma common, slopes form from pyroclastic material, generally found in association with other volcanoes

calderas

results from a volcano that explodes, collapses, or both, immense basin shaped depression larger than original crater

volcanic necks

pipe or throat of an old volcano that filled with solid lava

explosive eruptions

high silica, high viscocity, pyroclastic, granite

gentle eruptions

low silica content, low viscocity, basalt

diatrophism

2 types; folding and faulting

folding

results when rock is subjected to lateral compression, any scale, varied complexity, 2 types; anticline/upfold and syncline/downfold

faulting

occurs when rock breaks accompanied by displacement, occurs along zones of weakness in the crust, fault zones, 4 types; strike-slip, normal, reverse, oblique

strike-slip fault

linear fault trough, small depressions in the trough known as sags, sag ponds, offset drainage channels, shutter ridge

earthquake

vibration in earth resulting from sudden displacement along a fault, earthquake waves, magnitude

earthquake waves

Energy released by earthquakes moves in several types of seismic waves that originate at the center of fault motion the origin, Ground above origin experiences strongest jolt the epicenter

magnitude

relative amount of energy released during an earthquake

3 movement types in hydrologic cycle

surface to air (evaporation), air to surface (precipitation), movement beneath the surface (runoff)

causes of tides

gravitational attraction of moon and sun, more gravitational force on side of earth facing the moon, 2 bulges form on opposite sides to keep earth in orbit, 2 tidal cycles in 24 hour

currents

Subtropical gyres develop from surface wind patterns

the cryosphere

second greatest storage of earths water, largest ice pack covers most of arctic ocean surface, permafrost

groundwater

quantity depends on porosity and permeability

zone of aeration

close to surface

zone of saturation

water table intersects surface and water flows out, pores filled with water

waterless zone

pressure too great to sustain water

physical weathering

physical disintegration of rock without changes to its chemical composition, frost wedging, salt edging, temperature changes, exfoliation

chemical weathering

decomposition of rock material through chemical alteration of minerals, greater surface areas means faster decomposition, oxidation

mass wasting

larger scale movement, process by which weathered material is moved short distances by gravity, factors; angle of repose and impact of water on lubrication of rock material; fall, slide, slump, flow and creep

fall

rockfall, talus/scree, uniform accumulatio of rockfall material: talus apron; material tends to collect in cone shapes: talus cones

slide

landslide, instant mass slope collapse with no fluid flow lubrication, rotation of sliding material: slump

flow

wasting initiated or enhanced by water, water primary force, earthflows: water saturated land moves downhill; mudflows: originate in arid basins, muddy downslope flows that can accumulate large rock material

creep

unobtrusive downslope flow of soil and regolith, freeze/thaw and wet/dry effects, terracetters, soilfluctuation - soil flowage

stream order

Smaller numbers in stream order are more frequent, larger numbers are longer in length and watershed order

straight stream channel

short and indicative of strong geologic structure control

sinuous stream channel

irregular and gentle curvature

meandering channels

highly variable curvature

braided streams

multiple interwoven channels separated by loose bars or islands

dendritic drainage pattern

treelike pattern with random merging of streams

trellis drainage pattern

forms in areas of hard and soft bedrock in close contact, shape modified by structure of bedrock

radial drainage pattern

streams descend a concentric uplift

centripetal drainage pattern

streams converge into a uniform basin

stream channel characteristics

Streamflow normally confined to channels giving a 3d complexity, Friction effect of flow along bottom and sides of channel, Moves fastest on outsides of curves (cut bank), Slowest on inside of curves, accumulates alluvium (point bar)

landforms associated with floodplains

Bluff

* Cutoff meander
* Oxbow lake
* Meander scar
* Natural levee
* Backswamp
* Yazoo stream

hydrothermal activity

outpouring of hot water often with steam, usually in the form of a hot spring or geyser

hotspring

Hot water at Earth’s surface that has been forced upward through fissures or cracks by the pressures that develop when underground water comes in contact with heated rocks or magma beneath the surface

geyser

Special form of intermittent hot spring, hot water spews sporadically and most flow is a temporary ejection of hot water and steam upward

eruption patterns

Some geysers erupt continuously, hot springs that have constant water supply which steam escapes, Most geysers only active sporadically, Some eruptions are brief or some are minutes long, Temperature of erupting water is near waters boiling point (100C), Some eruptions are only a few cm high but some are over 45 meters

fumaroles

Surface crack directly connected to a deep seated heat source, little water drains into the tube of a fumarole, the water that does is converted to steam and expelled

* Features: steam continuously or sporadically issuing from a vent; a hot spring lacking liquid water

3 conditions for development of hydrothermal features

heat (most important), abundance of water that can seep down and heat up, weak or broken ground surface that allows water to move up and down easily

types of glaciers

continental ice sheets and mountain glaciers

continental ice sheets

Non Mountainous areas, outlet glaciers, only in greenland and antarctica

highland ice fields

ice sheets that submerge most underlying topography

alpine glaciers

develop individually instead of part of ice field; cirque glaciers

mountain glaciers

highland ice fields and alpine glaciers

mountain glacier main deposition mechanism

moraines, lateral and medial

pleistocene glaciation

began 2.59 mya, dominant environmental characteristic was refrigeration of high altitude and high elevation areas, peak 1/3 of land was covered in ice

causes of pleistocene glaciation

* Cold versus warm climate for glaciation


* Role of milankovitch cycles


* Variations in solar output and carbon dioxide in atmosphere
* Changes in continental positions
* Atmospheric circulation
* Tectonic upheaval

formation of glacial ice

* Orderly sliding of ice molecules


* Ice under extreme pressure deforms 
* Meltwater contributes surface for glacier to slide on
* Flow related to weight
* Snow compressed into granular form and more compression to glacial ice