intro (pangea and everything to do with it)

dinosaur as a ruling species

• causes other species tend to be much smaller and nocturnal to survive

non-avian dinosaur

• these are the ones that went extinct

avian dinosaur

 = bird

• not extinct

• Theropod descendants

  • Original therapods could not fly

  • Only gliding or short bursts of flying

archaeopteryx

• considered a dino and a bird

  • dino

    • bony tail

    • teeth

  • bird

    • wings

    • feathers

• conceived earlier as a transitional form or a missing link

• probably couldn't fly

  • feathers does not mean that they can fly

dinosaur grey areas

• non-avian and avian

  • ex.

  •  archaeopteryx

  • microraptor

    • 4-winged din bird

    • feathered

    • not sure if fly or gliding

  • amboteryx

    • dino bat

      • had feathers but membranes as well which is similar to bats

• Some had the capability to swim but also could be on land

  • ex. Spinosaurus

    • Semi aquatic

    • Feet that could paddle

    • Retracted nostrils

      • Nostrils are not at the tip of the nose

    • Dense bones for buoyancy

    • Broad tail that acts like a rudder

    • Most hunting was in the rivers

fossil location

• found on every continent

  • 'Cause only lived on land

  • In their time, the world was not made into the continents that it is right now

• not just dinosaurs

earth’s layers

• from outermost to inner most:

  • crust

  • mantle

  • outer core

    • liquid

  • inner core

    • solid

    • due to extreme pressure

• as you go inward

  • Fe, Mg, Ni will inc. and Si, Al will dec.

  • more metallic, pressure, temp., and density

• as you go outward

  • Si, Al will inc and Fe, Mg, Ni will dec.

  • more silicate minerals

• each is diff. in mechanical behav. and phase

crust

• solid, rigid and brittle (cuz cool)

• types

  • continental

    • thick

    • Si, Al

    • low density

    • mainly granite

  • oceanic

    • thin

    • rich in Fe and Mg

    • higher density

    • mostly basalt

mantle

• solid

• ductile plastic

  • plate move cuz heat allows the mantle to be malleable

• uppermost mantle

  • rigid and brittle solid

  • at the base of crust

  • divided into:

    • asthenosphere

      • ductile solid

    • deep mantle

      • less ductile solid

lithosphere

• uppermost mantle + crust

• lithosphere plates

  • moves during plate tectonics

plate tectonics

• Red Arrows

  • Away from each other = divergent

    • ex. Between the South American plate and the nubian plate

    • Forms a mid ocean Ridge

    • Well cause the land continents on them to be further apart millions of years from now

  • Towards each other = convergent

    • ex. between juan de fuca and north american

      • juan de fuca was a larger plate that was recycled under the North American one because of subduction

    • ex. Between the Indian Australian plate and the Eurasian plate

    • forms mountains

  • arrows moving past each other  = transform

  • single arrows = overall movement of a plate

• plates move ~ 0 to 10 cm

• Locations on the boundaries with subduction are more likely to experience hazards like earthquakes and volcanoes

tectonic theory

• lithospheric plates move and interact in response to forces in the earth

during subduction

• the subducting plate loses structural integerity

plate boundaries

• where 2 plates meet

• types

  • divergent

  • convergent

  • transform

divergent boundary

• move away from each other

• mostly on the seafloor

• causes seafloor spreading

  • hot rock rises up, melts and fills in the gaps between existing crust

• rock that moves away from the ridge will be older 

• ex.

  • Iceland

mid ocean ridge

• a long row of subsea volcanoes

• wraps all around the world

• ongoing process

convergent boundaries

• move towards each other

• types

  • ocean-continent

  • ocean-ocean

ocean-continent convergent boundary

• ocean always subducts under continental

• forms deep trench

• leading edge of continental crust get composed and deformed = mountains and volcanoes

ocean-ocean convergent boundary

• they collide with each other

• subducting plate will be older, colder, and denser

• the non-subducting plate will have volcanic islands

continent-continent convergent boundary

• results in large mountains

• sequence

  1. oceanic-cont

     1. oceanic subduction

  2. cont.-cont. eventually

     1. subduction stops

     2. collides into large mountains

• ex.

  • himalayans

  • indian and eurasion plates converge

transform boundary

• grind past each other

• crust is not created or destroyed

• forms along divergent boundaries

  • relives the stress it causes

• connects in diff. ways

  • connects spreading ridge + subduction zone = divergent and convergent

    • ex. Q charlotte fault

  • connects 2 plates moves in the same direction

    • ex. Nootka fault

diagram of layers

a = continental crust

b = oceanic crust

c = lithosphere

d = rigid uppermost mantle

• all of the above layers are involved in plate motion

convection

• occurs in the mantle

• sequence

  1. bottom most water is heated

  2. expands and becomes less dense

  3. rises

  4. that heat from the water is lost at the surface

  5. causes it to contract

  6. becomes more dense and sinks back to the bottom

plate movement

• through heat

• plate makeup

  • oceanic lithosphere is high density  and asthenosphere is weak

• lithosphere moves along the mantle

plate movement cause

1. plates get pulled down into trenches

2. gravity pushes the plates down the slope from the Ridge to the trench

• There are probably other forces as well

proof for pangea

• By matching fossils and rocks of the same age and type from different continents we can see where they might have been connected

  • Alfred Wagner

  • It is not possible for these organisms to have crossed the ocean

  • So the land masses must have been 1 supercontinent

• Ancient mountain belts have been split across divergent boundaries

from pangea to now

• Late Permian

  • 260 million years ago

    • Just before dinosaurs

  • One supercontinent

  • The South Pole has ice sheets all over

  • Glacial till

    • Ice moves across the surface of the earth and picks up rocks

• Late triassic

  • 220 million years ago

    • The time of the first dinosaurs

  • Pangea starts shifting north

  • The ice sheet on the South Pole has melted

    • Allows animals to migrate, although mountains are still blocking some passages

• Early Jurassic

  • 200 million years ago

  • Pangea starts breaking up

  • Lots of flooding because of less ice sheets and mountains building

• Middle Jurassic

  • 170 million years ago

  • Pangea breaks up even more

  • Sea levels rise enough to create inland seas

• Late Jurassic and early Cretaceous

  • 120 million years ago

  • Pangea breaks into two smaller supercontinents

    • Laurasia and gondwana

  • India starts moving N at 15 cm each year

    • Will collide with Asia 40 million years later

• Middle Cretaceous

  • 105,000,000 years ago

  • Gondwana breaks apart forming into Africa and South America

  • Australia is still stuck to Antarctica

  • High sea levels

• Late Cretaceous

  • 90 million years ago

  • Extreme flooding

  • Africa, Europe, India become flooded and the western interior seaway forms over North America

• Cretaceous paleogene boundary

  • 65.5 million years ago

    • End of the dinosaurs

  • Continents are almost at their modern position

  • Sea levels begin to drop