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EXAM #3

Nov 6, 2025

Sydney Fallon

  • No class for the next three meetings 

  • Lab due later 

  • EXTRA CREDIT

    • 25 points total 15 points to exam 10 points to general reading quizzes

Geomorphology 

  • The study of landforms and the processes that shape them 

    • Typically geographers that overlap with geology 

    • Geologists are concerned with rocks, the chemistry that makes them 

    • Geomorphologists are concerned with landforms such as mountains, sand dunes, beaches, etc. and how they are formed 

    • Seeks to explain shape, origin, spatial distribution and development of terrain features 

    • Landforms: 

      • Surface terrain features: mountains, valleys, plains, plateaus, canyons, bays, peninsulas, seas, etc…

Arkansas map 

  • Ouachita mountains 

  • Plains 

  • Arkansas river valley 

  • We have totally unique soils, foods, histories in these areas which are products of these different landforms 

Gemorphology reliefs

  • Low relief landscape: a landscape where there is not much elevation change : 

    • Mississippi river, alluvial plain, the entire state of Kansas 

  • High relief: landscape with steep elevation changes 

    • Ouachita mountains, rockies, himalayas 

Is Kansas flatter than a pancake? 

  • Conclusion: kansas is considerably flatter than a pancake 

    • Kansas has less of an elevation gain than a pancake does 

Geomorphology processes: 

  • Endogenic processes: (endo = internal) 

    • Processes that originate from within the earth and result in an INCREASE in surface relief 

      • Ex: plate collisions, volcanism 

      • The big island of Hawaii is growing as eruptions occur and the lava adds more rock to the island 

  • Exogenic processes (exo = external) 

    • Processes that originate at the earth’s surface, tends to decrease relief 

      • Ex: weathering, mass wasting, erosion 

Geomorphology Rising Relief: 

  • Endogenic processes outpace exogenic processes 

Mount Pinnacle in Little Rock: 

  • Overthrust fault due to plate collision 

Grand Canyon 

  • Product of exogenic processes due to erosion and weathering 

  • The colorado plateau was lifted up due to the collision of plates below it, but the canyon was carved out of it by the colorado river 

Layers of the Earth 

  • Earth condensed from a nebular of dust, gas and icy comets 4.5 billion years ago 

  • The entire planet was molten (still cooling and heated by the heat in the core of the earth today 

  • Gravity pulled mass towards the core 

Earth’s interior: 

  • Lithosphere = earth’s crust and uppermost mantle (70 km deep) 

  • Layers:

    • Crust 

    • Mantle 

      • Upper asthenosphere 

      • Lower mantle 

    • Outercore 

    • Innercore 

  • As you move towards the core you have increasing pressure, temperature, and density 

Earth’s planetary structure: 

  • Earth’s crust: 

    • 1% of the earth’s mass 

    • This is the exterior of the lithosphere 

    • Density depends on what type of crust 

      • Oceanic crust: basaltic makeup (Iron, silica, and magnesium) more dense

      • Continental crust: granitic makeup (silica and Aluminum) less dense

Minerals and Rocks 

  • Minerals are the building blocks of rocks 

  • Rocks are the building blocks of landforms 

  • Minerals: 

    • Inorganic and not part of the biosphere 

    • Naturally occurring, chemically distinct (can’t be created in a lab) 

    • Atoms are arranged in a regular pattern which forms solid crystals 

    • Gold, quarts, hematite, pyrite are all minerals 

  • Rocks:

    • Aggregate (collections) of one or more minerals 

    • Composed of several minerals to make one mass 

3 Major Categories of Rocks 

  • Igneous 

    • Molten rock material 

    • Magma below the surface, lava above the surface 

    • Cools and solidifies into two major categories of igneous rock: 

      • Extrusive 

        • Volcanic 

        • Extrusive volcanic rocks are rocks that form from lava that solidifies at the surface 

        • Fine grains 

      • Intrusive 

        • Plutonic 

        • Intrusive igneous rocks are molten magma that solidifies below the earth’s surface 

        • Crystal size increases as cooling time increases 

  • Sedimentary 

    • Accumulated sediment 

    • Unconsolidated materials that have been eroded from other rocks, deposited somewhere, and compressed and cemented (lithofied) 

    • Clastic sedimentary: 

      • Made from fragments of other rocks 

      • Sandstone 

      • Shale 

    • Organic sedimentary: 

      • Formerly living organisms that are deposited and lithified 

      • Plant material that is lithified = coal 

      • Marine organisms that have been lithified = limestone 

    • Chemical sedimentary rocks: 

      • Dolomite 

      • Due to chemical precipitance (chemicals precipitate into the water and result in formation of sediment) 

  • Metamorphic 

    • Changed form due to enormous heat and pressure 

    • Often found along plate collisions or mountains 

    • Harder than the parent rocks 

    • Foliation: 

      • Minerals compressed into platy or wavy surfaces

        • Limestone 

    • Non foliation (absence of platy or wavy surfaces 

      • Marble 

Rock cycle: 

  • Life cycle of minerals/rocks 

  • Origin of igneous rock: magma comes up to the surface and cools/crystalizes into igneous rock 

  • Erosion turns it into sediment like sand 

  • Sand is compressed and becomes sedimentary rocks 

  • A metamorphic process turns the rock into a harder version of itself 

  • The rock gets reintroduced into the mantel again and is melted down into magma 

Online lecture day 1: november 11 

  • Alfred Wegner: 

    • German scientist that studied the arctic and started out as a meteorologist and arctic explorer 

    • Developed the theory of continental drift 

    • First to voice the theory in the early 1900s with his book The Origin of the Continents in the Oceans 

    • In order to explain the arrangement of the continents he believed that they had been moving about 

    • Was not a geologist and was viewed as a crazy man by the field of earth science 

    • Because there were areas of continents that seemed to fit together like puzzle pieces he believed that there was a super continent that broke apart and moved around at some point (Pangea)

  • Continents in motion 

    • When Wegner put forth this theory in the 1900s we did not have the evidence we have to support it today 

    • The theory was not widely accepted until the 50s and 60s after he died 

      • Past glaciations: evidence of glaciation 

        • Glaciation leaves striations on the earth’s surface

        • These striations were found far away from the poles, which suggested they were further north in the past to allow glaciations to form 

      • Ancient mountain ranges: Scandies have same types of rocks and folding and faulting as the mountains in Greenland, suggesting they were created by the same event 

      • Terrestrial organisms: 

        • Animals that are unable to cross the ocean that are common to two different continents 

    • Plate tectonics 

      • Wegner’s theory was developed into Plate tectonics 

        • The lithosphere is fragmented (plates are broken up and move around independently) 

          • Seven major plates 

            • African, antarctic, eurasian, indo-australian, north american, pacific, and south american plates 

          • Plates converge, diverge, or move laterally from each other 

          • Pacific plate: made of all oceanic crust 

          • Eurasian plate: europe and asia 

          • Cocos plate and Nazca plates, etc. 

          • Subduction is when one plate is pushed under another 

        • Movement of plate tectonics: 

          • Divergent = plates pulling apart 

            • You have molten lava coming up from the mantle as a result 

          • Convergent = pushing together 

            • Earthquakes, volcanos, subduction 

          • Transform = two plates sliding against each other 

            • Ex: san andreas fault, earthquakes

      • Plate tectonics 

        • Why are plates moving? 

        • Divergent plate boundaries 

          • Caused by convection currents in the mantle 

          • There is tremendous pressure and heat in the mantle which causes the rock material to remain liquid 

          • As the mantle near the core of the earth is heated it causes it to rise, come up under the lithosphere (crust), move underneath it, cool, and sink down again. (similar to how hadley cells worked) 

          • The process of convection and the movement of the mantel pulls the crust in opposite directions

          • Causes divergent plate boundaries which form mid ocean ridges 

          • From these ridges, as you move further away ridges get older 

          • Mapping of the sea floor and the ridges and dating of the rocks found in these ridges were the final piece of support needed for the plate tectonics idea 

          • When a ridge comes up above the surface it is called a rift. This is where the mantle is close to the surface and can cause a lot of volcanoes or hot springs 

        • Convergent plate boundaries 

          • Three main styles: 

            • Continental - continental 

            • Oceanic - continental 

            • Oceanic - oceanic 

          • These plate densities determine the outcome. 

          • Continental continental: 

            • Neither plate is less dense so there is no subduction 

            • The crust is folded and faulted and the convergence results in the creation of a mountain range 

            • Ex: himalayas, ozarks etcc. 

            • Forms metamorphic rocks due to the pressure and heat formed by two continents colliding 

            • Himalayan mountains: 

            • Eurasia and india crash into each other and the himalayan mountains are formed. 

Gone day two: November 13 

Notes: 

The coast of Eurasia where india collided started out as a oceanic continental boundary 

  • When india collided with eurasia at that coastline it became a continental continental boundary as the oceanic crust subducted under india 

  • Mid ocean ridge (important)- where oceanic plates are being pulled apart in opposite directions causing seafloor spreading and the release of molten material which cools to create a ridge 

  • Distance between continents is increasing every year due to these 

  • Millions of years ago the continents all combined and collided to form Pangaea 

  • The collision between continents caused mountain ranges to form at the boundaries between plates and continents such as the smoky mountains appalachians etc. 

  • The ozarks in arkansas run east to west due to the compression coming from the south unlike other mountains which were formed by compression coming from the east. 

  • Oceanic Continental Convergence 

    • Ocean crust is less dense so it subducts and is forced under the continental plate. 

    • This subduction causes a trench in the ocean where the oceanic crust subducts. 

    • The oceanic crust that is being subducted is forced into the mantle and melted down by the heat and recycled. 

    • Mariana trench and oceanic trenches are associated with subduction 

    • This deep water is usually located right off the coast of these convergences

    • Typically there are volcanic ranges inside of the continental plate along these boundaries 

    • It is not known why but it is theorized that the oceanic plate is subducted and melted and the molten rock forces its way up to the surface. 

    • Pacific northwest is a subduction zone in north america, this is why there are volcanoes on the northwest portion of the US 

    • Earthquake hazards: 

      • The pacific northwest where the subduction is happening has pressure building up due to the sliding of the plates and causes earthquakes 

  • Oceanic Oceanic Convergence: 

    • Oceanic plates are both dense, but older plates are more dense so they are more likely to subduct than the younger plates. 

    • A trench is created along the subduction line and molten rock results from the recycling of the subducted plate 

    • Volcanos are formed underwater and rise up out of the ocean, forming chains of islands 

    • How to tell which is subducting? The plate with islands formed on it is the non-subducting plate. 

    • Ex: japan 

    • The pacific is where a lot of the action is for these convergences 

    • It is called the ring of fire (there is a concentration of volcanoes ringing the pacific basin. 

    • The pacific oceanic crust is being subducted by a lot of continents surrounding it. 

Tectonic forces and landforms: 

  • Landforms are not always going to occur on plate boundaries, sometimes they are fractures within plate boundaries 

  • Tectonic forces: 

    • Compressional 

      • Pushing from either end on a plate 

      • Often results in folding or faulting of the crust 

      • Ouachitas are an example of this folding. 

      • Produces anticlines and synclines (anticlines folds up, synclines are dips down) 

      • With this pressure rocks will either bend (fold) or break (fault) can also be caused by tensional force 

      • Fault scarf = sharp edge of a vertically displaced block on a fault 

    • Tensional: 

      • Pulling from weather side, apart 

      • Causes lateral faults (a type of shearing fault) 

      • San Andreas fault is a shearing fault

        • It is the boundary between the pacific plate and the north american plate 

        • The pacific plate includes san francisco los angeles and san diego and it is slowly moving away from the rest of California on the north american plate 

        • Eventually it will separate. 

    • Shearing 

      • Like a transform boundary, having two plates slide against each other in opposite directions. 

  • Faulting: 

    • Displacement of rocks along a faulting surface 

    • Caused by compressional and tensional forces 

    • NORMAL FAULTING - caused by tensional forces 

    • REVERSE FAULTING - caused by compressional forces 

    • TRANSFORM FAULTING - caused by lateral movement and transform movements 

  • Earth quakes: 

    • Vibrations and shockwaves in the earth from sudden releases of energy that radiate through the crust and diminish with distance. 

    • Rocks are ground against each other and the friction causes energy release that becomes an earthquake. 

    • The earthquake’s focus is where this energy originates from 

    • The epicenter is the area on the surface directly above the focus and it will have the strongest waves 

    • The earthquake cycle: 

      • We live in a mid continental fault and there have been enormous earthquakes in this area in the past 

      • Change in strain: Long period of inactivity after a previous earthquake where strain is built up over time 

      • Foreshocks: Hours or days before a large earthquake, may not occur 

      • Mainshock: major earthquake, includes the aftershocks that can come for up to a year after. 

      • Fault rupture = when an earthquake occurs 

      • We can predict the general time when an earthquake will occur based on the intervals of earthquakes on certain faults

    • Measuring earthquake sizes 

      • Moment magnitude = how much energy was released at the focal point of the focus 

      • It does not always translate directly to the amount of damage that occurs or the shaking intensity 

      • It depends on what type of rock the earthquake is happening on, bedrock will shake less and loose sediment will move around and liquify. 

      • Earthquakes occur along subduction zones and along faults 

      • The new Madrid fault is a mid continental fault and has less frequent earthquakes than other areas. However, when it has earthquakes they are more severe due to the energy not being released often. 

Third online lecture day November 18

Notes 

New Madrid earthquake: 

  • Estimated from accounts to be an 8.6 magnitude earthquake 

  • Fatalities are a result of not only the earth quake’s size but also the infrastructure

  • There were accounts of the mississippi river flowing backwards due to faulting downstream that caused the river to change course and flow back into itself and create the real foot lake in Tennessee. 

  • There were waves of religious revivals that occurred following this earthquake because it was such a significant event in the christian and native american communitites 

Tsunamis: 

  • Mega-thrust earthquakes are associated with tsunamis 

  • Oceanic plate involved boundaries that include subduction of an oceanic plate are the types of boundaries where we find these mega thrust earth quakes 

  • Mega-thrust earthquake: subduction of the oceanic plate combined with the opposite plate’s margin (front) being dragged backwards inwards by the subducting plate. The opposite plate will eventually rupture and thrust back

    • this displaces the ocean water and causes the water to spread out and create a tsunami wave. 

    • Not possible without subduction 

Igneous processes and landforms: 

  • Volcanic eruptions 

    • Effusive eruptions: mafic magma (low viscosity) 

      • Releases pressure more easily due to the lack of resistance 

    • Explosive eruptions: felsic magma (high viscosity) 

      • Due to pressure build up it is more explosive, though it does not erupt as often 

  • Volcanic eruption is dependent on mineral composition which determines viscosity, gas content within the magma, the pressure that the magma is under, and pyroclastic materials such as ash and rock that are spewed out. 

  • Hot spots: semi stationary magma plumes 

    • Magma plume is where molten lava is making its way up and sitting in the asthenosphere top, and the pacific plate is riding up on top of it. 

    • Eruptions are often during this. Once the area where volcanos have already been formed has moved off of the plume volcanos will form over new locations 

  • Volcanic Landforms (from least explosive to most explosive) 

    • Shield volcanos: 

      • Low viscosity effusive eruptions 

      • Hawaiian islands 

      • Low pressure results in a gently sloping or dome shaped volcanic cone that resembles a shield 

      • Gently sloping but not small. The low viscosity magma can flow further before cooling. These volcanos are large. 

    • Cinder cone volcanoes: 

      • Not really high viscosity 

      • Tends to erupt small cinders 

      • They stay relatively small due to the material they are comprised of 

      • Weathering removes a large amount of its mass regularly 

    • Composite cone volcanoes/ Strato Volcanoes: 

      • Mixed eruption types (effusive or explosive depending on the episode)

      • You can have cinders or rock material and ash first and then an eruption where magma flows out and hardens. 

      • The materials build up to form a composite layering of material to make up the volcano

      • These do not explode very recently, but due to the years of inactivity and pressure build up when they do explode it is often quite violent (similar to earthquakes) 

      • Ex: mount saint helens

        • On march 27th magma rises and comes into contact with the frozen water 

        • A massive earthquake causes a huge bulge on the mountain to collapse, removing a mile wide chunk of the north face 

        • The rock and gas shoot from the volcano into the air and a large portion of the mountain disappears instantly 

        • The dense plume of ash stretches fifteen miles high and breathing becomes impossible 

        • Meltwater and rock and debris pour down the slope at high speeds 

        • In two weeks the ash circled the entire globe. 

        • Pyroclastic flow: avalanche of hot gases, ash, rock fragments (can reach very high speeds due to high pressure and explosive power) 

          • Ex: pompei 

          • This includes an eruption that shoots this material inside of the atmosphere 

          • The eruption column rapidly collapses and rushes down the slope of the volcano.

    • Caldera Volcanoes: 

      • Formed as a result of a preexisting composite volcano

      • When the composite volcano is plugged up for a long time it explodes violently and empties out the magma chamber below 

      • Following the eruption the magma chamber is no longer able to support its ceiling and collapses in upon itself creating a caldera crater atop the volcano. 

      • This collapse in on itself fills the magma chamber with more material than before and ensures a larger eruption will follow once it has filled up with more magma and a new composite cone is formed  

      • Leaves a large caldera (hole from explosion) 

      • The caldera tends to fill up with water over time because the caldera crater is shaped like a bowl

      • A new composite cone forms from subsequent eruptions inside of this lake

 

November 20th Laptop dead see nick’s computer for notes 

Geomorphology: 

Endogenic processes 

  • Originates from inside of the earth and results in an increase in surface reliefs 

    • Ex: plate collisions and volcanoes 

Exogenic processes 

  • Originates from earth’s surface tends to decrease relief 

    • Ex: weathering, mass wasting, erosion

  • Denudation (exogenic process) 

    • Anything that wears away or rearranges landforms 

      • Weathering - break down of rock material into smaller pieces 

        • Disintegrates surface and subsurface rock into mineral particles or dissolves them into water 

        • Soil is finely fragmented mineral lparticles 

        • Regolith is broken up rock 

        • Bedrock = parent rock that produces regolith and soils through weathering. 

        • Jointing is where cracks have been formed in rocks and where weathering is more pronounced as a result 

        • Mechanical/physical weathering 

          • No chemical change 

          • Dominant in the cold dry climates 

          • Ex: frost wedging, salt wedging, temperature changes, pressure release jointing, root wedging

        • Chemical weathering 

          • Decomposition or chemical change 

          • Dominant in warm moist climates 

          • Ex: rusting, reaction with water 

      • Mass wasting - downslope movement of broken up rock 

      • Erosion - removal and deposition of rock material 

Nov 25, 2025

Notes 

  • Soils 

    • In arkansas, livestock and poultry are concentrated in the northwestern and southwestern areas of the state. 

    • Row crops are more common in the eastern portion of the state in the mississippi alluvial plane (the delta) 

    • Why? 

      • Eastern portions have good soil composition and landforms for flooding fields for irrigation 

      • Livestock ends up in areas where crops do not flourish 

      • It is the same up in the appalachians and the uplands

    • Colors of soil 

      • Iron in the soil gives it a red color 

  • Soil: 

    • Relatively thin surface layer made up of weathered mineral particles, decaying organic matter, living organisms, and liquids 

    • Just a mix of a lot of different shit 

    • In a teaspoon of soil there is more diversity in tiny organisms than the entire rainforest 

      • Rocks are broken up by weathering to make up soil 

  • What does soil do for us? 

    • It absorbs water quickly 

    • Soil has a lot of functions: 

      • Recycles organic waste 

      • Medium for plant growth 

      • Engineering mediums 

      • Modifies the atmosphere 

  • Soil composition

    • Inorganic materials such as sand silt clay

    • Loam = a mix of those 

    • Organic materials such as dead organisms or living bacteria

    • Water

    • Air 

  • Forming soil 

    • What influences the type of soil you get in different locations? 

    • Geology and different bedrock material 

      • Different minerals being weathered down affects what type of soil you will get 

    • Climate 

      • How much weathering and what kind of weathering is going on due to climate? Chemical or physical weathering 

    • Topography 

      • On a slope you will have thick soil at the bottom and thin soil at the top 

    • Biology 

      • Soil biota - organisms that incorporates a lot of carbon and organic matter into their bodies and releases it once they die 

    • Time 

    • Chemical weathering 

      • Oxygen and metallic elements oxidizes and creates a reddish color 

  • Organic matter exists at the top of the soil 

  • Rain is added to the top of the soil and is absorbed by the soil and the organic matter (plants) at the top. 

    • It also picks up fine particles such as clay, iron, aluminum and deposits it lower down in the soil 

    • Eluviation - material being picked up and carried down 

    • Iluviation - material being deposited by eluviation low in the soil 

  • Soil Horizons 

    • O horizon - surface area 

    • A horizon - mineral sandsilt and clay, good amount of organic material, plant roots

    • E horizon - eluviation horizon, light colored due to the clays and iron and aluminum have been leeched out of this area into the horizon below 

    • B horizon - reddish color due to accumulation of iron and other deposited minerals

    • C horizon - before you hit solid bedrock, unconsolidated broken up materials 

    • R horizon - unweathered materials 

  • Soils in the jewel moore nature reserve 

    • Large pore spaces drain water out 

    • Small pore spaces hold onto water 

    • Clay in the soil is negatively charged and attracts and holds onto positively charged nutrients and cations. 

    • This causes soil to hold onto nutrients in the soil that allow plants to thrive 

  • Soil orders

    • Alfisols - Al for aluminum, f for iron. Soils that are rich in these 

    • Andisols - formed from a type of magma in the andes mountains 

Dec 2, 2025

Notes 

Due dates: 

  • Online exam review quiz: thursday before class 

  • Lab seven due thursday five pm 

  • Extra credits: 

    • Reading quiz pyro: due thursday by noon 

    • New Earth System Map: due friday by midnight 

  • Exam: 

    • Tuesday dec. 9 at 11 am 

Are we supposed to convert temperature in the lab? Yes. 

Environmental history of arkansas 

  • Conway is in the middle of a hub of different geographic physiographic regions 

  • Ozarks, arkansas valley,, ouachita mountain, west gulf central plain, mississippi alluvial plain, etc. 

  • As we go higher in latitude, it gets cooler 

    • This affects the kind of plants or animals you can cultivate in these areas 

    • Because you are moving away from the equator it is getting colder 

  • The earth is old as fuck 

    • Not gonna ask specific like what years but will ask about themes 

    • Early formation of the earth: 

      • Life and photosynthesis took a long time to get started up 

      • During the cambrian explosion there was an uptick in biodiversity 

  • Formation of the ozarks and ouachitas 

    • Pre pangaea llanoria was south america 

    • Material was being eroded from mountain ranges and being deposited into a trent that became arkansas 

    • Fossil fuels and natural gas and nutrients were being deposited in this valley 

    • Then as plates collided the crust is folded and faulted which created the ozark mountains and valleys

  • Rock cycle: 

    • Rocks are being broken down, changed through weathering, igneous material is coming up through volcanoes etc. 

  • Geomorphology: 

    • Endogenic: originates in the earth 

    • Exogenic: originates outside of the earth surface

    • Formation of the ozarks and ouachitas: 

      • Pre pangea 

      • Exogenic processes are eroding material from mountain ranges and depositing them into a trench (where Arkansas was) 

      • The sediment gets compressed into sedimentary rock that we see a lot in the ozarks and ouachitas 

      • A lot of coal is formed in this area out of trees and other organic matter that is being dropped into these shallow swamps areas 

      • Collision of pangea : 

        • As they come together and collide they compressed the trench full of sediment

        • As it gets compressed you get folds and valleys and it creates mountain ranges and pushes up the ozark dome 

        • The ozark dome doesn’t get folded or faulted because it was further away from the collision zone 

      • Weathering and mass wasting 

        • Pinnajcle mountain 

        • The slope of pinnacle saw mass wasting and you can see the rocks that have been falling down the slope slowly 

      • A lot of sediment was carried down and deposited into the mississippi plane 

        • Down from the top left side of the state 

    • Climate during the quaternary geologic period 

      • Earth has cooled and glacials become more common

      • Caused by the 100 thousand year cycle that the earth goes through with its tilt and the influence it has on insolation and heating 

      • There are a lot of glaciers 

      • Cold glaciations, ice came down far into the planet 

      • When it recedes it doesn’t all recede at the same time 

      • When it melts a lot of meltwater is released and is introduced into the ocean 

      • Lasted 1.5 million years 

    • Crowley’s ridge 

      • Blip of topography a ridge that runs through the delta area 

      • Surrounded by flat flood plain land 

      • First place a lot of people settled due to arkansas been flooded swamps prior to draining 

      • During the last glaciation the glaciers ground up a lot of the surface and created loess that was washed down and deposited in the floodplains 

    • Development of the mississippi embayment 

      • Loess 

      • Washed down the river systems and is deposited in the floodplains 

      • It dries up and is blown away to the east 

      • Gets deposited up on a little ridge and grows 

    • Palynology pollen rain 

    • What pollen is in an area? You can determine a lot about past climates and ecosystems with pollen palynology 

  • Extinct pleistocene megafauna 

    • Short faced bear 

    • Wolly mammoth 

    • Sabertooth cat 

    • Horses were extinct in america but were brought back by europeans 

    • Megafauna is large bodied animals 

    • They went extinct during the holocene 

    • Did we make them extinct, or was it natural process?

Dec 4, 2025

Notes 

  • Mass extinction of large mammals 

  • Smaller mammals survived the mass extinction events 

  • Expansion of modern humans: 

    • People came out of africa and expanded throughout the world 

    • Large continents closest to africa are populated first and it took longer for islands to be populated 

    • There was a land bridge that connected siberia with north america that allowed people to travel across for a time 

  • We see the mass extinction of megafauna around the same time that human population exploded 

    • Blitzkrieg theory of pleistocene overkill: 

      • German theory that humans had no co-evolution with fauna 

      • Rapid expansion of human culture and killing off of megafauna 

      • Clovis culture: large spear projectile heads used to hunt megafauna 

      • Megafauna offered a large food source for people leading to them being hunted more intensely as opposed to smaller mammals 

      • Trophic Cascade: 

        • Loss of a higher level predator such as a sabertooth cat is caused by the extinction of their prey such as mammoths and mastodons 

    • Climate theory: 

      • Were climate changes occurring at the time of mass extinction?

      • Climate change may have caused megafauna to be pushed towards extinction due to changing their habitats 

      • However megafauna had evolved and survived through many interglacials and different climate changes without facing extinction  

      • Africa, australia, north america, madagascar’s arrival of people is followed by an extreme dip in large mammal population of their continents 

    • Prehistoric Pleistocene extinctions 

  • Passenger pigeons 

    • Large population and range 

    • Loss of habitat and overhunting caused loss in population 

    • Carcasses were used for pig feed and fertilizer 

    • Extinct in 1910 

  • Carolina parakeet 

    • Hunted for their colorful feathers 

    • Made a lot of noise and were shot due to annoyance 

    • Poisonous carcasses for cats 

  • Ivory billed woodpecker 

    • Very large woodpecker 

    • Went extinct maybe 

    • Due to loss of habitat

  • These are globally extinct species forever 

  • Locally extinct species in arkansas include: 

    • Bison 

    • Bears and mountain lions were extinct in arkansas for a while but some migrated back in after restrictions were put in place 

    • A lot of animals that had dependency on the prairie portion of arkansas have died out due to development of land 

    • Conway used to be a huge prairie land before it was developed into a city