Lecture 1 Flashcards
Are dinosaurs found on every continent?
Yes
Are dinosaurs terrestrial?
Yes
Can dinosaurs fly? Can they swim?
No, some could swim but generally didn’t
What do we call a non avian dinosaur?
a dinosaur
What do we call an avian-dinosaur?
A bird
What is a transitional form dinosaur?
Is a animal that has features of both dinosaurs (bony tail, teeth) and birds (wings, feathers) but have not been able to fly.
What type of animal is the Archaeopteryx?
A transitional form, is a dino-bird
What were microraptors?
is a four winged dino bird
What are amboteryx?
A animal which was considered a dino-bat
What adaptations did the Spinosaurus have to lead a semi-aquatic lifestyle?
Flat feet to paddle
retracted nostrils
dense bones to regulate buoyancy
a broad tail to act as a rudder
Where did the spinosaurus do most of it’s hunting?
In rivers
Dinosaurs are found on every continent why?
Because they lived on land
Dinosaur fossils came from which three major periods of time?
Triassic- During the supercontinent of pangea
Jurassic- pangea splits
Cretaceous- close to modern day layout, end of the age of dinosaurs
Earths internal structure consists of what?
The crust, mantle, outer core (liquid), and inner core
What elements dominate the crust and mantle?
silicate minerlas (like aluminum and silica)
Core is metallic (like iron, magnesium, nickle)
What three things increase with depth in regards to the earth?
Pressure, temperature, and density
What does differences in pressure, temperature, and density lead to?
Differences in phase and mechanical behaviour of the layers of the earth
What is the earth crusts texture?
rigid and solid
What are the two types of crust?
continental crust and oceanic crust
Describe continental crust?
Its thick- 20-80 km
rich in silicon and aluminum
low density and has a lot of granite
Describe oceanic crust?
Is thin: 5-10 km thick
Rich in fe and mg
has high density
basalt
Describe the mantle, what is it’s phase, where is it and what mechanical layers it can be split into?
The mantle is below the crust and is solid
The mantle can be split into several layers like the uppermost mantle, the asthenosphere, and the deep mantle
What is the uppermost mantle?
section of mantle that is rigid/brittle solid
What is the asthenosphere?
section of mantle below uppermost mantle, is ductile solid
What is the deep mantle?
section of mantle and is a less ductile solid
What is the lithosphere composed of?
the uppermost mantle and the crust
What is a ductile solid?
a solid that can easily deform under stress
Earths outer shell is broken into what?
lithospheric plates that move and interact in response to forces within the earth
A lithospheric plates consists of what?
includes crust and the uppermost rigid mantle
Plates move between how much a year?
0-10 cm
What is a plate boundary?
Places where two plates meet are called
boundaries are named based on what?
Boundaries are named based on the relative motion of the plates on
either side of the boundary:
What is a divergent plate boundary?
Plates move away from each other
What is a convergent plate boundary?
plates move towards each other
What is a transform plate boundary?
plates grind past eachother laterally
Are volcanoes and earthquakes randomly distributed?
No they follow plate boundaries
Describe divergent boundaries, where are they often found and what features do they create?
Can exist on land but mostly exist on the seafloor
hot rocks rise up, melt, and fill in gaps, creating new oceanic crust, because the plates are constantly moving away from each other, rocks get older as you move perpendicular away from the ridge
Seafloor spreading produces what?
a continuous row of subsea volcanoes called the mid-ocean ridge that wraps around the world
Thingvellir National Park, Iceland lies on what?
The boundary of two plates that are pulling away from each other
Why is the oceanic plate subducted?
Because it’s denser
What forms at the ocean-continent convergent boundary?
a deep trench forms at the boundary and the leading edge of the continental crust gets compressed and deformed producing mountains and a arc of volcanoes
What were the canadian rocky mountains built by?
subduction
What happens during an Ocean-ocean convergent boundary?
The two plates collide and the older, colder, denser plate subducts and a arc of volcanic islands forms on the overriding plate
What are the himalayan mountains a product of?
The convergence of the indian and eurasian plate
Continent-continent convergence produces what?
very large mountains ex: mount everest
What is a transform boundary?
Is side to side movement where no crust is created or destroyed
Where do transform boundaries commonly form and why?
They commonly form along divergent boundaries to relieve stress
What do transform boundaries connect?
Most connect spreading ridges, some connect spreading ridges to a subduction zone (for ex: Q. Charlotte)
Some connect two plates moving in the same direction at different rates (like the nootka fault)
The San andreas fault is which type of fault?
a transform fault
What is convection and how does it relate to plate movement?
Water is heated from below and it expands and becomes less dense and rises, then it cools contracts becomes dense and sinks- this heat is released via convection from the mantle and drives plate tectonic movement
Tectonic plates likely move because of what?
Tectonic plates likely move because of the relatively high density of
oceanic lithosphere and the relative weakness of the asthenosphere, the lithosphere slips along the mantle due to low friction
What are the dominant forces causing plate movement?
Plates are pulled down into trenches
Plates are driven down the slope from ridge to trench by gravity
How do we know where the continents used to be?
By looking at similarity of fossils and rocks on
different continents, it is possible to tell where
continents were and if they were connected.
What fossil evidence is there for pangea?
non swimming land-dwelling reptile fossils were found on different continents, for ex cynognathus have been found in africa and south america.
Fossil remains of mesosaurus have been found in africa and south america
Lystrosaurus have been found in africa, antartica, and india
Glossopteris fossils have been found on all southern continents
What is the geologic evidence of pangea?
Rocks of the same age and type are also found on continents that are now separated by oceans.
Ancient mountain belts have also been split across divergent boundaries.
What were the characteristics of pangea just before the dinosaurs (late permian)?
Was a single super continent, ice sheet over the southern pole, had glacial tills
What were the characteristics of pangea at the time of the first dinosaurs (late triassic)?
Pangea shifts north, ice sheets melt, animals can migrate and distribute and some mountains may block some passages
What were the characteristics of pangea at the time of the early jurassic?
Pangea starts to break up, then flooding occurs with a lack of cie sheets and mountains build
What happens to pangea in the middle jurassic?
Pangaea continues to break up
Sea levels rise; inland seas
What happens during the late jurassic and early cretaceous?
You have laurasia and gondwana formed, and india moves North at 15cm/yr, it collides with asia 40 million years later
What happens to pangea during the middle cretaceous?
Africa and S. America split
India moves N
Australia stuck to Antarctica
Have high sea levels and gondwana breaks apart
What happens during the late cretaceous?
-
Africa, Europe, India
flooded
Western Interior Seaway is formed
What happens during the cretacous-paleogene boundary
Continents are near modern position, sea levels start to drop, and the age of the dinos ends
