Earth's Layers: Crust, Mantle, Core

Layers of the Earth

• Earth consists mostly of oxygen and iron.
• The four layers of the Earth are the crust, mantle, outer core, and inner core.
• The crust is the uppermost layer.
• The mantle is the largest layer.
• The outer core is liquid and flowing.
• The inner core is solid and denser than the outer core.
• Oceanic crust is thinner and denser than continental crust.
• Continental crust is light due to its composition of light materials.
• Oceanic crust sinks more into the mantle because it is denser.
• The asthenosphere is a soft, flowy part of the mantle.
• The outer and inner core are made of iron.
• The crust consists of oxygen and silicon.
• The upper part of the mantle moves alongside the crust.
• The inner core is denser than the outer core because it contains nickel instead of silicon.
• The sloshing around the outer core generates Earth’s magnetic field.
• The lithosphere consists of the crust and the upper part of the mantle.
• Minerals are structured, solid, made of elements, naturally occurring, and non-organic.
• Obsidian is not a mineral due to its rapid solidification and lack of internal structure.
• Ice is a mineral since it meets all mineral criteria: natural, non-organic, organized, etc.

Continental Drift and Plate Tectonics

• Alfred Wegener developed the continental drift theory.
• High school evidence for continental drift includes puzzle pieces, fossil records, and climate zones.
• Catastrophism describes a relatively young Earth shaped by disasters.
• Uniformitarianism posits a very old Earth shaped by gradual change.
• Silicate minerals primarily compose crustal rocks.
• James Hutton is considered the founder of "Modern Geology," having visited Siccar Point
• Hutton's key ideas included:
  • Rejection of catastrophism: Earth is old.
  • Gradual change: Changes take place slowly.
  • Uniformitarianism: The past can be understood by studying the present.
• The law of superposition: younger layers are on top of older layers.
• Marie Tharp pioneered mapping the ocean floor, providing evidence for tectonic drift.
• Paleomagnetism is non-climate, fossil, geologic evidence for continental drift.
• Seafloor rocks closest to the mid-ocean ridge have normal magnetic polarity.
• Rocks farther away exhibit opposite magnetic polarity, demonstrating magnetic reversal.
• Seafloor spreading occurs at mid-ocean ridges, where plates move apart, creating new ocean floor.
• Oceanic crust spreads laterally and descends back into the mantle at deep-sea trenches.
• The ridge axis is where seafloor spreading happens.
• Mid-ocean ridges form series of normal faults, potentially triggering earthquakes.
• Isochron maps connect areas with the same time/age.
• Continental crust is generally considered older than oceanic crust.
• Tectonic plates consist of both oceanic and continental crust.
• Plate tectonics explains the Earth as divided into constantly moving rigid plates.
• Divergent plate boundaries involve plates moving apart, creates crust.
• Convergent plate boundaries involve plates moving together, creates crust.
• Transform plate boundaries involve plates sliding horizontally.

Volcanoes

• Oceanic crust forms volcanoes by bringing water into the mantle, which lowers the melting point of the rock above.
• Subduction involves denser, older rock being forced under another plate.
• Continent-continent convergence forms mountains.
• All plate boundaries except transform boundaries can form volcanoes.
• Mantle plumes: columns of hot mantle rock that can cause volcanoes.
• Volcanoes form over hot spots
• The direction of a tectonic plate's movement relative to a stationary hot spot: The oldest volcano indicates direction.
• Slumping is when rock further from seamounts or oceanic crust becomes denser due to the lack of heat.
• Magma forms underground whereas lava appears above ground.
• The extrusive realm is found above ground and produces coarse rocks.
• The intrusive realm is found within the earth and produces fine rocks.
• A phenocryst is a separate mineral in a rock that indicates the rock is intrusive and formed slowly underground.
• Phaneritic textures are coarse, while aphanitic textures are fine.
• Porphrytic rocks contain phenocrysts.
• Mafic rocks are metal-like and contain magnesium and iron.
• Felsic rocks contain aluminosilicates.
• Bowen’s Reaction Series charts the different reaction temperatures for minerals.
• Slow cooling results in large rock size.
• Fully melting: Rocks have the same composition when they fully melt
• Partially melting results in a more felsic composition.
• The primary rock type of oceanic hotspots is basaltic.
• The primary rock type of continental hotspots is rhyolitic.
• Felsic lava is viscous, sticky, and explodes massively.
• Felsic lava forms through subduction zones and hot spots.
• Intermediate lava is between felsic and mafic in composition.
• Mafic lavas can be chunky/blocky or pahoehoe, which has a flowy texture.
• Pyroclastic debris consists of pieces of rock from volcanoes.
• Lahars: mixtures of ash and water formed by pyroclastic debris create mudflows.
• Mafic volcanoes found at oceanic hotspots and mid-ocean ridges.
• Felsic volcanoes found at subduction zones and continental hotspots.
• Mantle basalts can rise through continental crust due to igneous activity.
• Pyroclastic flows are faster but have shorter distances than lahars; lahars contain water and have more stamina.

Rock Types

• Pumice consists of foamy pyroclastic material.
• Large Igneous Provinces contain many igneous rocks and are linked to major eruptions and extinction events.
• Large Igneous Provinces form randomly relative to tectonic plates.
• Flood basalts result from basaltic lava flooding an area.
• Intrusive rocks can form concordantly parallel or discordantly across layers.
• Batholiths are very visible igneous rock formations.
• Common coarse rocks include granite (felsic), diorite (intermediate), gabbro (mafic), and periodite (ultramafic).
• Common fine rocks include rhyolite (felsic), andesite (intermediate), and basalt (mafic).
• Euhedral rock formations feature well-formed, sharp crystals.
• Anhedral rock formations are messy and lack boundaries.
• Metallic and non-metallic are the two types of luster.
• Non-metallic luster types are: pearly, vitreous, silky, and earthy.
• Island arcs form chains of volcanic islands at ocean-ocean convergence zones.
• Continental arcs are volcanoes on continental crust.
• Volcanoes form at divergent and convergent boundaries.
• Basalt/shield volcanoes (mafic) form at mid-ocean ridges and oceanic hotspots and have runny, low-viscosity magma.
• Composite volcanoes (rhyolitic) form at island and continental arcs and have thick, high viscosity magma.
• Stratovolcanoes result from a combination of effusive and eruptive activity.
• Effusive eruptions feature lava pouring down the sides.
• Explosive eruptions feature lava explosions.
• High-viscosity lava is better for explosive eruptions.
• Andesitic lava has medium viscosity and forms composite volcanoes.
• Common magma types are basaltic, andesitic, and granitic.

Minerals

• K-feldspar is mostly felsic (granite/rhyolite).
• Plagioclase feldspar is mostly intermediate (diorite/andesite).
• Olivine signifies the presence of ultramafic periodite.
• Pyroxene indicates mafic (gabbro/basalt) and some ultramafic (periodite) rocks.
• Hornblende is found in felsic (granite/rhyolite) or intermediate (diorite/andesite) rocks.
• Quartz appears mostly in felsic rocks (granite/rhyoliteand a little in intermediate (diorite/andesite) rocks.
• Mafic rocks do not have quartz.
• Sediments derived from fragments of other rocks are clastic.
• Biochemical sediments consist of shells or shell fragments.
• Chemical sediments form from mineral precipitation out of water.
• Chemical weathering is on the tin.
• Rainwater acts as both due to a slightly acidic pH and can act as both.
• Physical weathering by frost is more prevalent in cold areas.
• Frost weathering occurs as water freezes in cracks and splits rocks.
• 75% of the Earth's surface is covered by sedimentary rocks.
• Sedimentary rock incorporates biological, physical, and chemical records.
• Sedimentary rocks contain fossils and groundwater.
• The ocean serves as the primary destination for sedimentary rock deposition and freshwater serves as a secondary destination.
• Clastic refers to rocks made of older rock fragments.
• Transport of sedimentary rocks by rivers is more efficient than glaciers.

Sedimentary Rocks and Processes

• Rivers sort clasts by size.
• Higher-sorted sedimentary clasts indicate higher water velocity during transport.
• Sedimentary rock formation involves weathering, transport, deposition, and lithification.
• Weathering breaks rocks down.
• Transport moves material.
• Deposition occurs when sediments precipitate out of solution after reaching a base level.
• Lithification forms rock through compaction and cementation.
• Rocks with the same pores as pumice are called cellular rocks.
• Stream deposition changes with water velocity seasonally.
• Compaction compresses soil with overlying material.
• Cementation binds rocks together.
• Cementation is stronger than compaction, effectively forming a "cement."
• Turbidites form when steep continental edges cause underwater landslides that deposit coarse material.
• Coarser sedimentary materials are found near land, while finer materials are found near sea/water.
• Joints are fractures in rocks with no movement.
• Clast packing refers to the spatial arrangement of clasts in sedimentary rock.
• Framework-supported clasts are large and in contact with each other, in contrast to matrix-supported clasts which consist of large clasts held together by smaller grains.
• Clastic rocks are made from other rocks.
• Biochemical rocks are derived from shells or shell fragments.
• Chemical rocks are made of minerals precipitated from solution.
• Conglomerates consist mainly of rounded rock fragments which are greater than 2mm
• Breccia consists of angular HUGe clasts.
• Sandstone rock consists of sand sized clasts with quartz etc
• Siltstone consists of silt sized clasts but are compact
• Shale is comprised of silt sized clasts and splits easily
• Clast sizes, in order of least to greatest measure clay, silt and then sand.
• Biochemical rocks are coquina, chalk and fossiliferous limestone. - Coquina is poorly cemented shells and fragments and porous. - Chalk is soft fine and chalky with microfossils and shell debris. -Fossilferous limestone is well cemented and has very visible shells.
• Chemical rocks are dolostone, chert and halite. -Dolostone is altered limestone and reacts with hydrochloric acid when powdered. -Chert is sedimentary rock found within other rocks and are extremely hard, choncidal fracture and contain halite.

Earthquakes

• Earthquakes are shockwaves caused by crust/mantle stress along faults.
• Strain is the deformation of a material as a consequence of stress.
• Shear stress is to slide.
• Tension is to be pulled apart.
• Compression is to be pushed together.
• The epicenter is the spot located directly above an earthquakes focus.
• Foreshocks refer to the the earthquake shocks prior to the main earthquake.
• Aftershocks refer to the earthquake shocks after the main earthquake.
• It is hard to predict precisely when earthquakes will occur.
• Hiding under table or in a doorway are both good procedures to follow before an earthquake
• Two types of earthquake waves surface and body.

Earthquake waves

• Primary waves travel like a slinky are longitudinal and move faster.
• Secondary waves travel up and down and move slower.
• Love waves move side to side
• Rayleigh waves move in a circular motion.
• Surface waves cause more damage.
• Secondary waves can only move through rock
• Primary waves can move through both rock and the ocean
• Divergent boundaries can result in earthquakes
• A low angle reverse fault is still a reverse fault just with at a low angle.
• Where the hanging wall moves up relative to the footwall is a reverse fault.
• In a normal fault the hanging wall slips down relative to the footwall.
• Reverse faults can put old rock on top of new rock in deposition.
• Stress is a force per unit area.
• Old school Richter scale, modern more precise moment magnitude and destructiveness are ways to measure earthquakes.
  • A seismograph is a device used to record earthquakes.
  • Seismograms are records of seisimic reports
• Old-fashioned seismographs used a weight w a spring that were NOT secure and pen bounce with the waves.
• Earthquake stations have 3 seismographs one for each XYZ axis.
• 3 stations are needed to find an earthquake’s epicenter.
  • With only 2 there may be two different points of the earthquake but 3 can narrow it down.
• Body waves are NOT used because they die too quickly.
• Earthquakes allow us to get inside a rocks inner readings and the waves bounce of certain things in different frequencies.
• Factors that influence moment magnitude are fault and rupture size and seismic energy.
• A seismograph start measures the P wave and then the Surface wave.

Earthquake hazards

• A convergenet plate boundary can result in an deeply underground focused earthquake.
• Shallow earthquakes are the most dangerous and NOT to be confused with surface waves.
• Even with no plates failed rifts can cause earthquakes.
• Liquefaction happens in earthquakes where the soil behaves like a liquid.
• Pressure from temperature and the rock material are what makes a rock’s ductile or brittle behavior.
• Temperature affects the amount gooey temperature a rock can get.
• During an earthquake water gets shaken which causes the ground to sink. -The best thing to do build structures to avoid liquefactrion is to build deep into the past gooey soil to reach the bedrock!
• Ductlile deformation: It bends.
• Brittle: It breaks.
• 99% of the epicenters are likely to lie within plate boundaries.
• Fast rates of deformation means it will shatter but a slower behavior will let that rock bend.
• We get longitudinal looking mountain structures because of magma heighing is up causing basis mountains.
• Lateral is to slip Strike fault
• Thrust, normal, reverse are all Dip-slip fault
• Put a person so you see it

Metamorphism

• Metamorphic rocks change as it forms making deduction easy.
• A rock is metamorphic if it changes mineralogically and/or texturally when heat pressure and fluids are applied.
• Similar is intrusive igneous rock for a metamorphic and hard to study.
• When rock becomes lower in the ground metamorphism occurs at the mountain belts.
• As plate rocks go into the ground as a result of subductions, the rocks start to change bringing material with it
• When a high temp with a shallow depth and the rock is metamorphosed it it’s a contact metamorphism
• However pressure temperature and not for a metamorphic rocks, lithification occurs which is rocks becoming compacted but not transformed.
  • You can NOT be underground and cold with low pressure
• Blue schist is a hard to stufdy and occurs in deeper depths high pressure and low temperatures.
• Mountain type metamorphism: occurs often and results in new rocks with a new set:
• shale, slate, phyllite schist and gneiss(separation in bands)

Geologic Dating

• migmatite is an optional find form of gene with parts melted.
• Fully melted rocks are igneous not metamorphic and regional metamorphism is related to plate collisions.
• The protolith is the original rock formation.
• Four non- foliated rocks in this course marble protolith is limestone quartzite protolith is sandstone amphibolite and metaconglumerate.
• Filation causes rock to end up laying itself in leaves. -Non foliated has pressure on all sides. - The mineral measures the given intensities of metamorphism. - High mineral equals a high temperature formation. - A metamorphic zone is areas with equal metamorphic intensities.

Rock Behaviors and Dating

• CaCo3 same as protolith for marble
• No Gnessist and schist cannot always be a substitute for other rock forms sometimes may be garnet
• The boundaries are between all electronic plates and earthquakes will all act.
• The Sills are parallel, the logic likes cross layers and the magma causes the lithosphere to start.
• Shrear earthquakes is all from shallow depths and all has brittle behavior.
  • a joint set is a bunch of joints in the rock
  • The amount of continental rifting the mantle will causes it to rise as the lip causes fold and that causes basins and mountains.
• What two places will you most likely find a normal false midocean rifts.
• Reverse faults compression forces the rock to slide up.
  • Thrust faults are common in the rockies.
• A snow shoveller.
• Ducitle deformation happens at 15 km.
• Anticline and the is both types of duct tiles and convex side upward from the oldest.

FAUNAL SUCCESSION

• Faults fall in axial planes and the anticline is a convex side with new oldest forms.
• Concave upside are the youngest forms and they form inside the synclines.
• With fossils over the ground it’s an aticlone, the behavior can be paired alternating between Syncline and Autocline
  • Rock that cuts other through rocks are old and stratigrapic corolitation means a fossils age.

Relative Dating

• Fossils have a unique pattern for goeograpic dating
• Each fossil/time has a different name for the eras -Fossils contain limited time large and are still protected -Fossils of the exact age are from the
• Rock type is used to only prove general terms -An unconformity is caused by sedmiatry
  • Fossil record is used for radiometric dating
  • Absolute time is the actual time -Two factors for isotopes and heat life from c14 -A great time for isotopes are the isotopes in it

The Rock Record

• All tools aren’t always perfect
• The four eras Precambrian which lasted the longest before old, middle and cenizoic era
• We live in the last bit, huge time spend pre cabrian and the revolution is relatively bli
• You can use cross cutting rocks near by yo fine thier age
• The chart is the lesbian flag
• Found age using space rocks ans zircons
• Holocene used to Be part of the anthropene
• A phtostiglomerate is congolemurat
• The anthropocene used to earth more then human
• Percabrian, paleo meso cen. All of them, and all different. More on the sheet look at sheet
• Streams in the middle but the flow are all very different.
• turbulant is more messy and lamellar is straight as broad —Turbulent leads to more erosion. Volume of water is discharge
• Mid top in the is to get away from the troublesome flow.
• 4.94% Fresh water with almost 3% frozen
• water sheds channel are what origin surface.
• Topographic line boundaries between others are the water sheds, you and someone.

Waters

• Suspended load is flow
• Dissolved ions around 35% is suspensions
• Beddragged at the bottm
• Iona dissolved in the loads around 35%
• Suspended most material
• Capacity stream the material it carries
• Sedmiant leaves and general very finner
• River shaped and can be at concave shape
• gradient gradient shows at the source and long from the long profile
• Damm affects the sediment in the built up water
• Bread constant motion. channels stabilthed
• Mind craft curv y
• In cut the bank to the curve

Rivers and More

• Oxbow lake are the cu off lakes. Flood plain is a land near by .
• The Niel is the deltas name.
• flood amount and years increase with the log.
• Yes as probability .
• Add average and see the result
• Area * valovity will result into the answer
• There are always an uncertainty always.
• TDS Shows hard ness
• Magneitc is according to the outer
• True north north pole
• UMT Latitude and longitude.
• Cast then north
• 60 is a degree subdivided.
• Calculate and reduce
• Scales show scale Same process again

Ground Water

• Pores

• Ground is at what

• Fill the sediments Recharges the area

• Out to still out to the out

• Fed ground waster is flunet

• Ground waster. -

• Static a fluid Water all well.

• Aquifer is the most common

• Aquifers dephined that well is used.

Water

• V. water
• Dpnd water bending Widen the deptrions Larger the defroestation. Ground w is that Safe salt or chlorine Gett hings go down Water makes you good.

Karst Toplography and Land Subsidence

• A cave was dissolved in water 62 and and the water creates from ions.
• There are 3 D for horizontal and to give the numbers for that to happen.
• Formation is is to what FM stand s for and mm is for the mm
• Mass movement is going down.
• Slow is is is
• Range is from 35 to 45
• We love that all of those
• Mudeslide
• Common w in the is
• When water that is
• Save it to run it
• Slow the.
• Water helps more.

Hazards and the Earth

• They fall down to
• The dam caused water to move over causing rocks slide and thus flood
• Rocks in the area all had different composition and was in all for a disaster to happen the dam was set to move over. The andmed caused an rain
• Antacline with shale and then mining
• There are areas will slide for a repeating point. Tree cause causes more
• Water slopes
• Highways take down rocks They have are risks what is up Good quick they just need salt

Fossilisation

• There are different types of deaths for bones rots. We can see for
• The part are strong
• We use a the thing to
• It to look at this

Oceans

• Quiet water is
• The sand and more
• We can look ate the wave and what causes
• Waves have s space in trhe font top
• We want tot walk -spits island, lagoons.
• It have too do
• Cliff's get eaten cause the water is there and the tides are too shallows
• Water in a side makes tunnel
• There were still some to to put pillars
• You put those a ocean or in big lakes Toe berm can build houses Plants
• Absorm to potect. The eldr mor bet Focus at the head, Drop water is there Tsunami sub land .

Tsunami

• Water has to move. Heavy We can se see you but run..
• RUN High safe for all of them.

Glaciers

Temp and snow

• Permeant A time to move them Most land We has. Mount land

• We has no for sure Abla not what one is water Snow line. More low snow levels

• D downhill. Shine and land. Cente land

Measure and tap faster Middle Depedn the point Brittle breal Brittle an d land Down up Buildupe of the watrr V shaped Unsorted Forms . Retre and dump for. Boulder back

Rocks

. Point with a mess Sorte carpet. Toke rocks path Holes to lakes To lakes Avance What now orbit . Plate on land . Ecc

Top License for the geoscience and more Name for what the mean. The logs measure the info . Measure rocks . Mentors rules Pro and the Rocks .

• Hy and geo.