geog 213 midterm study

Relief

the difference in elevation between the highest and lowest parts of a landscape

Height of mountain ranges

Controlled by uplift and subsequent erosion

Continental drift

proposed by alfred wegner. similarity of rock formations on both sides of the atlantic

Mantle convection

magma upwelling and heat from the core can dive magma to create convection cells. this can lead to the spreading of plats

Evidence of mantle convection

ocean ridges and sea floor spreading. mirrored processes of polarity switches found at the spreading ridge

Cratons

dead interiors of continents

Constructive plate margin

creates new rock by magma bubbling up

Destructive plate margin

one plate goes under, deep rocks cool. melted minerals uplift to create volcanoes.

Back arcs

Destructive plate feature. heavier complex minerals create a convection cell behind volcanic arcs

Thrust belts

faulting and folding of sediment

Subduction

ocean plates meeting. one goes under so magma upwells. creates volcanoes

Collisional

continent hits continent one eventually subducts. zone of thickening and crumpling

Conservative plate margin

moving along each other. no material created or lost

Interplate hotspots

upwelling plumes of magma. flood basalts

Intraplate rifting

streching a plate apart. dominated by fault block mountains

Ocean crust

thin and heavy basalt = more dense

Continental crust

thick and light plutonic = less dense

Isostasy

how different objects float

Crust

Ocean crust subducts due to dense nature, while continental lifts due to less dense

Erosion rates

tied to hydrology, which is tied to climate

Ductile deformation

Folding, thinning, shearing

Brittle deformation

faulting

Consequent drainage

water follows slope of the lands

Subsequent drainage

water follows underlying geology

Antecedent drainage

cuts through underlying geology

Dendritic

tree like, plains consequent drainage

Parallel

tree like thin lines. follows steep straight slopes

radial drainage

volcano style drainage

Trellis

follows eroded folds. subsequent drainage

Rectangular drainage

eroded limestone, subsequent drainage

Annular drainage

eroded domes subsequent drainage

Multibasanal drainage

sinkholes drainage, subsequent

Contorted drainage

subsequent eroded metamorphic drainage

Horizontally bedded rocks

layers with oldest rock on bottom. dendritic drainage

Cliff and bench

Layers have different resistances to erosion. horisontally bedded. with lava flows

homoclines

layers with same dip. Scarp is the exposed rough edge, with the dip being the peak smooth slope

Cuesta

not super steep homocline

Hogback

steeper homocline

Razorback

super steep vertical homocline

Anticline

the peak hill of a fold

Sincline

the dip bottom of a hill of a fold

Plunging folds

angleded downward into ground

Non plunging folds have

older rock in anticline peak, youngest in sincline middle

Eroded domes have

annular drainage. pressure from salt or igneous intrusions push the rock up

Fractures

breaks with no displacement or movement

normal fault

foot slopes down and is higher (slide style)

Reverse fault

Hanging edge is higher than foot (lighting bolt style)

Volcano shape

depends on temp and composition of lava

low magma temp

sticky and explosive

high magma temp

thin and runny

Basalt lava

high temp shield volcano

Andesite lava

medium thickness, stratovolcano

Rhyolite volcano

high viscosity, low temp plug dome

Felsic rock

less dense making up continental crust

Mafic rock

more dense rock making up ocean crust

Phaneritic

Visible grains in the rock = plutonic

Aphanitic

fine non visible grains = volcanic

Phrphyritic

mixed grains - subvolcanic

Clastic sedimentary rock

created by rock fragments

Non-clastic sedimentary rock

created by chemical precipitation

Compation

crushed by weight of other rock, reducing pore space and water. clay is a good compactor

Cementation

groundwater carries ions that hold grains together. can be chemically altered

Metamorphic

alterations of structure or minerals of parent material by heat and pressure

Foliated

moving and squishing rocks to align minerals in sheets

Non foliated

heat and changing mineral structure of rock

Weathering

in situ breakdown of rock

Erosion

wear of rock by wind, water, ice or flows

Physical weathering

disintegration of rock into smaller pieces. increases total surface areac

Chemical weathering

decomposition as a result of chemical reactions. new resulting chemical substance

Physical weathering examples

Pressure release, hydration, salt crystal growth

Pressure release weathering

physical, release of trapped rock releases pressure creating cracks and expansion

Exfoliation weathering

physical, rock breaks into sheets as it is uncovered after landscape modification

Thermal weathering

physical. The change of temp on the rock causes expansion, while cooling causes contraction

Hydration weathering

physical, water bonds to clay causing expansion and breaking into lines

Frost action weathering

freeze thaw causes the water in joints to expand and shrink repeatedly

Salt weathering

physical, precipitation of salt crystals that can expand when hydrated. causes the rock to expand

Chemical weathering

the decompsition of rock thorugh chemical reactions

Solution weathering

dissolving soluble minerals into water. saturated minerals precipitate out creating evaporate deposits

carbonation weathering

carbonic acid breaks down limestone into soluble products

hydrolysis weathering

hydrogen ions pull out clay from rocks

Hot mafic rocks are _ to weather

hard

cooler felsic rocks are _ to weather

easy

Oxidation of sulfides weathering

chemical, rust can increase strength

Biophysical weathering

roots can split rocks, burrowing animals can increase water infiltration

Mechanical weathering is ideal for

freeze thaw locations

CHemical weathering is ideal for

warm moist climates

Elastic

same stress = same deformation, remove stress = recovery

Plastic

cant recover from stress

viscous

responds with flow to stress

angle of internal friction

stability of interlocking parts

mass movement trigger

when driving forces are greater than resisting forces

Mud

like liquid

Debris

materials, water, debris

soil/earth

unsaturated fine sediment material, plastic

rock

blocks detached from bedrock

Translational

flat straight movement

rotaional

u shaped movement

vertical

straght down fall

Flows and glides

translational movements

GLides and slumps

slides