Download Dynamic Crust

Dynamic Crust
I. Evidence of Crustal Movement
A. Crustal Changes –
1. Non-horizontal Strata:
a) _______________________________________ strata are normally deposited in
_______________________________________ layers.
(1) Any change from horizontal tells us there was _____________________
movement.
No Motion
Tilted Strata
Faulted Strata
undisturbed
Folded Strata
B. Fossil Evidence –
1. _______________________ fossils found at high _________________________________ suggests crustal
_______________.
1.
Normal
Environment
2.
2. Shallow water marine fossils found at great ocean depth suggests crustal
______________________________ /________________________________.
C. Theory of Continental Drift – Alfred _______________________
1. 200 _____________, all the continents existed as one large land mass called _________
2. Evidence Supporting Continental Drift:
a) ________________________-like Fit - the ________________________________ of the continents
seemed to have ______________________________________ like a large jig-saw puzzle.
(1) __________________ coast of South America fits well with the ________________
coast of Africa.
b) ______________________ Clues – certain ancient life forms are _______________________ as
fossils on widely __________________________________________________________________________
(1) __________________________________ - reptile, ____________________________________ - fern
c) Rock Clues - Mountain ______________________ and rock patterns
(1) The ______________________________________ mountains on the _______________ coast
of the ___________, are geologically ______________________ to the Caledonian
Mtns. in Scotland, _________________________ and __________________________
(2) ________________________________, ______________ and mineral _____________________
are________________________________ on the ________________ coast of ___________________
and the Western coast of ______________________.
d) _______________________________ clues (1) _________________________ - forms from the burial of plants in ________________
________________________ environments.
(a) Currently found in the colder climates of N. America and
______________________________________.
(2) ____________________________________________________ - contains corals from warm
______________.
(a) Currently found in _________________ latitudes such as _____________.
(3) Glaciers –
(a) Ancient rocks of the same age near the _________________________ in
S. America, S. Africa and other southern continents show
evidence of _____________________________________.
All the continents once existed as one large land mass called Pangea
What general rule can you make from this evidence?
D. Theory of Seafloor Spreading – Harry _________________
1. The idea that the seafloor itself moves, and carries the continents with it,
as it expands from a central point.
2. Topography of the Ocean Floor:
3. Evidence of Seafloor Spreading:
a) _____________ Evidence – as the ___________________________ from an ocean ridge
____________________________, the ___________ of the rock _____________________
(1) As the distance from a ___________________ increases, the age of the
rock will __________________________.
Oldest
Youngest
Age
Oldest
b) Paleo- _______________________________ Evidence – ancient magnetic clues in the
_______________-bearing basalt on the ocean floor supports the theory of seafloor
spreading.
Polarity
S
Normal/Positi
ve
1.
N
Reverse/Negativ
e
II. Plate Tectonics – thin, lithospheric __________________ are in motion and “______________”
or ride on the ______________________________________, the plastic-like layer beneath the
lithosphere.
A. Earth’s Layers and Composition
1. The Lithosphere is composed of the crust and ____________________ mantle
2. The Asthenosphere is a ________________________________________ layer of the upper mantle.
3. The Earth is layered according to _______________________ values.
Crust 5-_______ km
Mantle __________ km
Outer Core ___________ km
Inner Core ____________ km
Cross Section of Earth: pg ______ ESRT’s
B. Driving Force Causing Plate Tectonics
1. _______________________________ currents:
a) Hot, ______________ dense, magma from deep within the mantle ____________________
b) As the magma rises it cools, becomes _______________ dense and __________________
2. The convective ________________ of magma in the mantle ____________________/_______________
lithospheric ___________ across Earth’s surface.
3. Major Plates and Plate Boundaries: pg ________ ESRT’s
a) The Theory of Plate Tectonics states that Earth’s lithosphere is divided into
sections called lithospheric plates.
b) _______________________________________________ and interact with each other at plate
________________________________.
(1) Direction of Relative Plate Motion(a) ____________________________: ____________________ from each other
(b) _____________________________: ____________________________ each other
(c) ____________________________: _______________ passed each other.
Divergent
Convergent
Transform
(2) Divergent Plate Boundaries – This is where two plates are being
________________________________________. (splitting of Pangaea)
(a) _______________________: Oceanic crust, _________________________________
(b) ___________________: Continental crust, _______________________________
(3) Convergent Plate Boundaries – where two plates come together
and ____________________________.
(a) Plate ______________________________ determines the ___________________
of the collision.
(b) ____________________________ - _____________________________________
(i) More dense __________________ crust will _________________,
or dive under, less dense __________________________ crust
and sinks into the __________________________.
(ii) Sometimes rising through the continental crust as it
becomes __________________________.
(iii) The _________________________ plate, oceanic, subducts
under the South _____________________________ Plate,
continental.
(c) ________________________________ - _____________________________________
(i) Continental crust collisions will produce mountain
________________________ events.
(ii) Indian plate colliding with the Eurasian plate; forming
the __________________________________ mtns.
(d) _____________________________ - _____________________________ - Slab Pull
(i) Oceanic crust collisions produce ________________________
and __________________________________________.
(ii) Trenches and island arcs formed __________________ and
the ____________________________________ islands of Alaska.
(4) Transform Plate Boundaries – where two plates move ____________________
each other in ______________________________ directions.
(a) The Pacific plate and North American plate move passed each
other; creating the ____________________________________, in California.
C. Earthquakes –
1. Seismology: The branch of science that studies Earthquakes
2. Cause: ___________________________ movement of Earth’s crust at plate
_____________
or faults.
a) Types of Faults:
(1) _______________________ fault – ________________________________ boundaries
(a) Hanging wall moves down
(b) Usually produces ____________________, _______________________ quakes.
(2) Reverse fault – ___________________________________ boundaries
(a) Hanging wall block moves _________________________.
(b) Produces ________________________, _______________________ quakes
(3) __________________________________ fault – _________________________ boundaries
(a) Blocks move side to side
(b) Produces ____________________________, ________________________ quakes
3. Earthquake Terms –
a) Focus : The _________________ beneath the Earth’s surface where _________________
movement releases seismic waves/_________________________
b) ___________________________________: point on Earth’s surface _______________________________
________________ the focus.
Key
Shallow = within 75 km of
Earth’s surface
Intermediate = 75 to 300 km below
Earth’s surface
Deep = 300 to 700 km below
Earth’s surface
Depth
(km)
100
350
700
c) Seismic waves: energy released from the focus in the form of waves.
(1) P-waves - _________________________ waves are _____________________________
and at travel __________________ and arrive at monitoring stations before
any other earthquake waves.
(a) P-waves can travel through solids and liquids.
(2) S-waves - ____________________________ waves are _______________________ and
travel at __________________ and arrive at monitoring stations after
primary waves.
(a) S-waves can only travel through solids.
P-Wave
(3) By analyzing wave patterns scientists have been able to infer the
interior ____________________________________ of Earth.
S-Wave
d) Seismo______________________ : instrument used to measure and record
earthquake waves at seismic stations.
e) _________________________________________________: the paper report of wave data
recorded by a seismograph.
4. Locating the Epicenter of an Earthquake
a) Record arrival times of the S and P waves, from at least ______________ different
seismic stations.
Seismograph
Station
Arrival Time
P-wave
Difference
in Arrival
S-wave
Time
Distance to
Epicenter
Houston
Chicago
Seattle

Use pg _________ of ESRT’s to find the distance
each wave traveled.
b) Use a drawing compass to make accurate circles around the seismic
station location.
Seattle
Chicago
Houston
c) Where the three circles meet is the epicenter. Mark this with an X
5. Measuring an Earthquake
a) ________________________ Scale: used to express the strength or ___________________________
____________________________ by an earthquake.
(1) The scale increase 10-fold each level
(a) A 3 is ____________ times greater than a 2, and 100 times greater
than a ________.
b) ______________________________________ scale: measures the ___________________
damage caused by the quake on a scale of ______________________.
6. ________________________: gigantic sea-wave
a) Speed: ___________________________
b) Height: __________________________
D. Volcanoes:
1. Causes of Volcanic Activity
a) ___________________________________: Oceanic- ___________________________ crust
(1) _________________________ and rifts contain volcanoes and hydrothermal
______________________.
b) ___________________________________________: Oceanic – Oceanic crust
(1) ______________________ bearing minerals, brought down with the suducting
plate causes the rock to __________________________.
(2) This magma___________________________ through overlying ______________________
and creates deep sea volcanoes.
(a) These volcanoes ___________________ overtime and can sometimes
form _________________________.
c) Converging: _______________________________ - ______________________________________ crust
(1) As the ___________________________________________ plate is pulled deeper into the
upper_______________________________, the plate beings to melt and rises as
magma intrusions.
(a) Builds _______________________________ on the surface of the
overlying
continental crust.
2. The ___________________________________________________________________________________ -
3. ________________________________________: results from the ______________________ movement of a
tectonic plate over a “fixed” point in the mantel that is _________________________ than the
mantel around it.
a) Causes:
(1) A narrow _____________________ of hot ______________________ convecting up from
Earth’s ____________________ - ______________________ boundary.
(a) Called a mantle _____________________________
(2) Upper- mantle ___________________________________________________
b) Ex: ___________________________________________________
4. Types of Volcanoes
a) _______________________ Cone – non-explosive eruptions
(1) Built from repeated _______________________________________________________________.
(2) ______________________ sloping sides.
b) ___________________________ cone - _____________________________________ eruptions.
(1) Built from _________________________ (volcanic _______________________ & ___________)
(2) ____________________________ sloping sides.
c) ______________________________________ cone – repeated _____________________________________ &
___________________________________ eruptions.
(1) Built from _________________________________ layers of lava and ___________________
(2) _________________________________ sloping sides
5.
Volcanic/_____________ features – Igneous intrusions