Geologic Cycle:Endogenic=internal,plate tect&magma upwellings. Exogenic=external,wind,wat,erpsopm. Igneous:form.Melting Magma(beneathsurface) Lava:magma that extruded Granit&Basalt Intrusive(cools below surf pluton-100km2batholith)Extrusive(above surf)90% crust Jointing-parallel cracks Exfoliation-peel-off (Ex.Dome) Sedimentary:compounds settling(weathering,compaction,cementation-Limestone&SandSto) strata=layers,Clastic sediments=transported water,wind,ice,grav Chemical sediments=minerals dissolved solution Metamorphic:altering processes(heat&pressure) Harder compression, crushed,cooked,shear and stress Ex:Marble,Gneiss,slate Foliated=texture distinct wavy lines of min. Plate tectonics:adrift cause convectionCurrents in upper mantle 6cm/y,Pangae=allEarth-225mil y Triassic Period,Tectonic=building-constr Sea-floor-spreading 64miKm mountain ridge,magma rises, youngest crust-oldest208mil.Subduction ZoneCont crust lighter tha ocea(driven underneath) Mariana Trench near Guam 11030m bellowsea.14Plates Divergent Bound-spreading apart-Great Rift Valley in EAfrica. Convergent Bound-colliding(o-o,c-c,o-c) Jap2011 Transform Bound-slide laterally-no-new-crustEx San Andreas Hot Spots-upwelling material(migrate,move,fixed) beneath crust-Hawaiian-Emperor Islands chain(80milY) Seamounts-mountains-oceanfloor Ring-of-Fire(Pacific Rim)(Pacific Plate is subducted) Volcanos-vents,conduits from asthenosphere&upper mantle through crust and out Earth surf Landforms developed=volcanos Beneath surface magma chamber colletcs magma before eruption Crater round depression near top.1300-1500V cones and mount, 500-600active (1 eruption in 10000y),50V erupt/y..Lava=molten rock Pyroclastics=tephra-chunks rocks launched out.Aa-rough jagged surface-cracking of the thick lava skin.Pahoehoe-coiled,rope-looking surf. Pele'sHair spun volcanic glass-stretched from lava.1Cinder Cone small,short, cone-shaped hill from previous eruptions,Made of pyroclastic mat. And scoria2Caldera-basin shaped depression after top collapsed(kettle) Can becom lakes 3Flood Basalts plateau basalts-long blankets of lava spreading over surface-Horizontal nature-Lava comes out of fissures(linear vents)4Shield Volcano-similarity to a knight's shield lying face-down -gentle&gradual slope, resulting crater at top/ From effusive erup 5Composite Volcano-massive explosive erup-known also stratovolcanoes Cone shaped &steep slope Effusive eruptions -gentler, magma is fluid&low viscosity gases easily escap Few pyroclastics, small explos Explosive eruptions-Magma higher viscosity, gasses are trapped& build pressure.Lg pyroclastics,little lava (Kilauea-Hawaii,M St. Helens) Where volcanoes? Subduction zones c-oceanic,o-o, Spreading zones-sea-floor cont rifts.Hot-spots Earthquakes-Tension-stretching of rock strata-produces thinning of the crust and normal faults Compression-shortening of crust-results in folding of crust & reverse faults.Shear-twisting/tearing motion- causes the crust to bend and strike-slip-faults.Strain-what rocks do when they are under stress.Folding-rocks bend-Ridges are the top peacks, while through are low valleys. When rock layers slope downward & away from the topis called anticline, when downward and in towards bottom called syncline Plunges = when axis of a fold not parallel to surface Overturned anticlines are when folds are pushed together somuch that they startto topple over.Faulting-rocks break.-much pressure When fracture occurs energy is released quickly earthquake.There are 3 types of faults based on how they are tilted in relation to fault plane.1Normal Faults result from tension stress rocks are pulled apart. After fracture one side will move vertically. Side of fault that moves downward = hanging-wall side, the higher side of fault footwall side Cliffs formed are called fault scarps, or escarpments. 2Thrust or reverse faults when rocks are pushed together with compression stress. In reverse faults the hanging wall moves upward so it is hanging above the footwall side (landslides).If fault plane is at low angle, one block will slide on top of the other -called thrust fault 1994 Northridge L.A earthquake Wind aeolian Deflation blowing away small sediment Abrasion scraping of larger rocks by small part in wind.Ventifacts rocks with aeolian abrasion erosion. Yardangs lg rock/ridge structures shaped by win into grooves/elongated. Blowout depress/deflation hollows lg.Basins cause huge am sediment removed thr deflation Saltation lg sand partcl move by win/wat thro irregular skipp&bounce(80%) Surface Creep lg rock pieces pushed horiz Suspension fine mater,silt&clay carried in air by win Deset pavement/gobi,lag gravel,gibber plain compact landscape of rocks/pebbles/gravel (by deflation) Dunes Barchans crescent shapedR Transerse ridges of sand at right angle to win Longitudinal ridges are not at rightAngl Parabolic crescent L Loess deposits of dust by win.
3Strike-Slip Faults when fault movm is horizontal from shearing. Itcanbe right-lateral or Llateral-no clips-creates rift vallesys San Andreas Horst rock blocks that faulted upward Graben-rock blocks faulted downward Basin&Range type of topography abrupt relief & angular rock structures Bolson-low area between 2ridges,has slopes and basin Playas = salt crust areas left behind when evap occurs in bolson/ valley Orogenesis birth of mountains.Accumu of materials cause crust to thicken, follow by uplift Seismic waves-Surface waves move along the top of crust,P-waves (pressure w) are compressional, the rock/magma these waves move through vibrates parallel to the wave motion S-waves (shear waves) cause rock to move at 90degree angle to the wave motion(not th liquid).Focus-hypocenter-the point bellow the surf along a fault Epicenter-point on the surf that is above focus Foreshock-shaking that happens bef mainEven Aftershock shaking that happens after main earthquake (usually smaller) Richter Scale-measures seismic waves Seismograph record vibrations Landforms-individual aspects of Earths topography(mount,valley,hill,caves) Landscape collection of landforms in one area Geomorphology study of landforms Denudation=any type of wearing away or moving od landf(water,wind,waves,ice)=weathering.Endogenic process-tectonic uplift create the initial landscape, the base point.Exogenic processsuck as weathering and erosion, work to wear landsc.destabilizing event=new starting point caused by physical event(fire,volcan etc)When system's energy >rocks resistance, reached geomophioc threshold or tipping point.1.EquilibriumStability,2DestabilizingEvent,3Period of adj,4New equi stability.Erosionwhen pieces of earth transported away.(mass movements=large scale)(factor cause weathering water,glaciars,wind,waves).Depositionmaterial set down in new place.Differential weathTop rock protects rock beneath.Slopesare the curved,inclined surfaces.The convex of slope(at top) called waxing slope, bottom one called wanin slope.Mechanical weath-frost action,salt-crystal growth, pressure-release joiting. Blockfieldrock pieces collect around.Talus steep slope form by boulders falling.Chemical Weth-Hydration,Hydrolysis,Oxidationo,Carbonation.Biological Weath-lichen take nutrients from rocks.Angle of repose is the slope steepness.Creepis slowwSolifluction cold climates-alternates freezing and thawing.,Slide downward-Slumps slides that rotate on curved surface.-Flow-fluid-earth-flow or debris flow,Fall.Groundwat-bellow ground-(im)permeable,infiltration-downward movement of wat.Vadose zone-soil contains wat&air(zone of aeration)Phreatic zone-all soil pores filled with wat(alsozone of saturation)Top of phreatic zone=wat table.Aquifers=permeable layers of soil(Sandstone&limestone)Aquicludes=impermeable layers.Fluvial=related to streams&riv. Hydrology=study of water and how it moves. First streams=primary stre first order,2combine=Second strea,2combine=Tertiary strea. Perennial streams=wat year roundEphemeral strea=wat dur rainy seasonIntermittent strea=have wat for some parts of y.Wat shed/drainage basin=all area belongs to strea/riv.Drainage divides-separates watersheds.Dendritic-tree-branchesTrellis-vineRadialaway centralDerangedno-pattern.Sheetflow=wat moves down slope in a thin sheet.Rills=small indentations/cracks collect wat. Gullies=biggerRills AmazonRiv=largest Fluvial.Discharged=amount of wat that moves dur a time (cubic-m/s-or cfeet/s) Q=wdv(Qdischarge,wwidth,ddepth,vvelocity) Fluvial landforms-formed byErosion,Trans,Deposition.Base level=lowest elevation a stream can erode.Hydrograph=measure streams dischargeBase flow=low discharge amount during dry seasonsPeak flow=highest am.Of discharge after precip event.Erosiondepends on turbulence(hw rough wat is flow)andabrasion (how rock particles in wat scrape along the sides).Disolved load=solution Suspended load=small particles that moe within wat setl at bottom. Bed load=larger pieces .Deposition:Aggradation=stream channel filled in by deposition of eroded mater.Alluvium=material that has been deposited(fertile) Alluvial fans=fan-shaped landscapes when an ephemeral stream empties out from narrow canyon.undercut banks=high vel areas-opposite=point bar deposits.OxbowLake=cut-off portion of river.Delta=triangular shape of alluvium that forms at river mouth.Floodplain=flat,low area around riv.Levees=barriers run parallel to riv Karst Topography (caves systems) carbonation=limestone interacts with water(chem weathering).