1/7/2001
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Course introduction |
- Rock cycle implies geologic recycling, just like
plate tectonics.
- Uniformitarianism, the present is the key to the
past.
- Catastrophism is not a black box, but the product
of the laws of nature we see operating today.
- Geologic time: 1mm/yr = 1km/My
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1/9/2001
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Geologic time and dating Reading:
usgs geotime
Alternates:
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- Differentiate relative and absolute dating.
- Understand the law of superposition, and the
principal of original horizontality.
- Describe the principles involved in radiometric
dating, and list some of the isotope pairs uses.
- Know the geologic
time scale.
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1/14/2001
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Earthquakes and velocity structure GT 8-19 |
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Understand
the classification of igneous rocks based on texture or cooling
(intrusive/extrusive), and chemical composition (mafic,
intermediate, felsic)
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Differentiate
the three different types of faults, and give representative plate
settings where they occur.
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Given
the orientations of the two focal planes and the compressional and
dilational axes, plot a focal mechanism diagram and determine the
type of fault represented.
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Define
the following earthquake terms: focus, epicenter, magnitude, and
the three main types of waves (P, S, and surface).
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1/16/2001
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Earthquakes II |
- Differentiate the Richter and Mercalli scales
- Discuss the plate tectonic settings, and rocks involved, in
plutons, stratovolcanoes, shield volcanoes, and MORB
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1/21/2001
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Holiday |
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1/23/2001
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Crust, Mantle, and core GT 19-30 |
- Discuss how we can use earthquake arrival times to determine the
layering in the crust.
- Describe the layers of the ocean crust, and how they corresponds
to ophiolites.
- Discuss the gross composition and structure of the mantle and core.
- Key terms: gabbro, peridotite, pillow basalts, and sheeted dikes
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1/28/2001
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Out of class exercise |
Obtain simplified core records for the 10
DSDP/ODP holes nearest your paper area, using either the library or
leg reports: http://www-odp.tamu.edu/publications/ |
1/30/2001
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Sedimentary rocks: Ocean Basins (SO231
text), p.114-120
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- Discuss the classification of sedimentary rocks as clastic
or chemical, and the divisions by size.
- Discuss where silica oozes, carbonates, red clays, terrigenous
sediments, and ice rafted sediments occur, and why they have this
distribution.
- Discuss what the vertical sequence of rock types can tell about
the history of the location.
- Discuss the importance of rads, diatoms, forams, and coccoliths
in the ocean sediments.
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2/4/2001
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Deformation,
isostasy, and heat flow GT 30-45 |
- Differentiate brittle and ductile deformation, and the
conditions leading to each.
- Differentiate the Airy and Pratt models of isostasy, and what is
required for isostasy to operate on the earth.
- Discuss why the thickness of the crust and plates varies
depending on how we measure it.
- Discuss how heat flow varies on the earth.
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2/6/2001
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Continental drift and magnetism GT46-61 |
- Understand how we use Euler's theorem to model motion on
the earth's surface.
- Discuss the kinds of evidence for plate motions, especially
paleoclimates.
- Describe how paleomagnetic sampling can reveal a paleo-latitude
but not a paleo-longitude, and why that sometimes causes
scientists to use apparent polar wander (APW) paths.
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2/11/2001
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x-week |
Sea floor spreading GT62-75 |
- Discuss why marine magnetic anomalies form, and how they
provided the clinching evidence for plate tectonics.
- Discuss the use of magnetic anomalies to date the seafloor,
determine spreading rates, and infer the former locations of plate
boundaries.
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2/13/2001
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x-week |
exam comp time |
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2/14/2001
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x-week |
exam in x-period,
Michelson 103 |
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2/18/2001
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Holiday |
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2/20/2001
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Framework of plate tectonics GT 76-102 |
- Discuss recent absolute measures of plate velocities (GPS and
VLBI)
- Discuss the importance of hot spots in providing an absolute
reference frame
- Differentiate total reconstruction poles, stage poles, and
instantaneous poles of rotation
- Understand why motions of multiple plates on a sphere require
that some of the rotation poles must move.
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2/25/2001
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Ocean ridges GT 103-121 |
- Discuss the charateristics of ridges in terms of plate
spreading rate.
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2/27/2001
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Transform faults GT 122-137 |
- Describe the bathymetric expression of transform faults and
fracture zones.
- Differentiate right-lateral and left-lateral strike-slip faults.
- Describe how motion along a ridge-offsetting transform differs
from a classical strike slip fault.
- Discuss what happens at transpressional and transtensional bends
on strike-slip faults.
- Describe leaky transforms
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3/4/2001
3/6/2001
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Subduction zones GT 138-173 |
- Discuss the classification of metamorphic rocks in terms
of pressure and temperture, and the explanation for paired
metamorphic belts in terms of plate tectonics.
- Describe the features associated with the subduction zone
boundary: forearc bulge, trench, subduction complex, volcanic arc,
backarc basin/marginal sea, and backarc ridge
- Discuss the distribution of earthquakes across a subduction
zone, and why they include both normal and reverse mechanims.
- Key terms: blueschist, turbidites
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3/11/2001
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Spring
Break |
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3/13/2001
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Spring
Break |
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3/18/2001
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Mountain ranges GT 174-208 |
- Differentiate Andean and collisional mountain belts
- Discuss the distribution of earthquakes in an orogenic belt and
the Benioff zone
- Discuss how indentation tectonics works in southern Asia
- Discuss how suspect terranes form, and how they might relate to
oceanic plateaus
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3/20/2001
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Rifts and sedimentary basins GT 209-247 |
- Describe the rifting process, both when an ocean basin forms and
an aulocagen forms
- Describe the Wilson cycle
- Discuss the thermal impact of stretching the crust, and the
thickness of sediment that can accumulate.
- Discuss how detachment faults and accomodation zones work in
crustal extension in three dimensions.
- Key terms: backstripping, foreland basins, inversion tectonics
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3/25/2001
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Regional tectonics exercise |
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3/27/2001
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Rifts and sedimentary basins GT 209-247 |
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4/1/2001
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x-week |
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4/3/2001
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x-week |
exam comp time |
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4/4/2001
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x-week |
exam in x period |
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4/8/2001
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Exam review |
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4/10/2001
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Mechanisms plate tectonics GT 248-268 |
- Discuss the problems with the expanding earth hypothesis.
- Discuss the use of corals to calculate the length of the year.
- Discuss the phi scale, and how it complicates interpretation of
graphs with sediment size as one axis.
- Discuss how the pipette method derives sediment size
distributions.
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4/15/2001
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Mechanisms plate tectonics GT 248-268 |
- Discuss the distribution of heat flow in the earth's crust.
- Describe how mantle convection could work.
- Discuss the forces acting on plates
- Discuss the areal distribution of convection cells.
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4/17/2001
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Implications of plate tectonics GT 269-295 |
- Discuss how Archaen and Proterozoic plate tectonics might
resemble or be different from current processes.
- Discuss how plate tectonics affects economic geology, especially
with fossil fuels, and climate-controlled deposits like laterites,
bauxite, and evaporites
- Key terms: greenstone belts, granulite gneiss, source/
trap/seal.
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4/22/2001
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Paleo-oceanography and
Paleoclimatology GSA
Today |
- Discuss the use of isotopic studies (d13C or d18O)
to infer past temperataures or mixing in the oceans
- Discuss
what happens to the Black Sea in a glaciation when global sea
level drops
- Describe
how geologic evidence can suggest the direction of flow into or
out of a stratified body of water like the Black Sea
- Discuss
why the behaviour of climate and ocean circulation on geologic
time scales can be beneficial for current issues like global
climate change
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4/24/2001
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Course
review |
- Discuss the role of geologists as historians of the earth, and
why this has practical applications
- Describe how catastrophes can be incorporated in a
uniformitarian view of geologic history.
- Appreciate the differences between the geology of the oceans and
the continents.
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