SO461 Syllabus--Spring 2003 (3/23/2003)

Lecture

Wed 01/08/03 

Course introduction
  1. Rock cycle implies geologic recycling, just like plate tectonics.
  2. Uniformitarianism, the present is the key to the past.
  3. Catastrophism is not a black box, but the product of the laws of nature we see operating today.
  4. Geologic time: 1mm/yr = 1km/My

Mon 01/13/03

Geologic time and dating

Reading: usgs geotime

Alternates:

  1. Differentiate relative and absolute dating.
  2. Understand the law of superposition, and the principal of original horizontality.
  3. Describe the principles involved in radiometric dating, and list some of the isotope pairs used.
  4. Know the geologic time scale.

Wed 01/15/03 

Earthquakes and velocity structure 

GT 8-19

  • Understand the classification of igneous rocks based on texture or cooling (intrusive/extrusive), and chemical composition (mafic, intermediate, felsic)
  • Differentiate the three different types of faults, and give representative plate settings where they occur.
  • 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.
  • Define the following earthquake terms: focus, epicenter, magnitude, and the three main types of waves (P, S, and surface).

Wed 01/22/03 

 Earthquakes II
  • Differentiate the Richter and Mercalli scales
  • Discuss the plate tectonic settings, and rocks involved, in plutons, stratovolcanoes, shield volcanoes, and MORB

Mon 01/27/03 

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

Wed 01/29/03 

Sedimentary rocks: 

Ocean Basins (SO231 text), p.114-120

  • 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.

Mon 02/03/03 

Deep Sea Drilling Program Project (no class attendance)  

Wed 02/05/03

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 lithosphere varies depending on how we measure it.
  • Discuss how heat flow varies on the earth.
  • Differentiate free air and bouguer gravity anomalies

Mon 02/10/03

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.

Wed 02/12/03

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.

Fri 2/14/2001

 exam in x-period  

Wed 02/19/03

 exam comp time  

Mon 02/24/03 

Wed 02/26/03 

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.

Mon 03/03/03 

Ocean ridges 

GT 103-121

  •  Discuss the characteristics of ridges in terms of plate spreading rate.
Wed  03/05/03 Lecture Comp Time  

Mon 03/17/03 

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

Wed 03/19/03

Mon 03/24/03

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 mechanisms.
  • Key terms: blueschist, turbidites

Wed 03/26/03

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
Mon 03/31/03 exam in x period  

Wed 04/02/03

Writing Exercise Three

Mon 04/07/03 

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 accommodation zones work in crustal extension in three dimensions.
  • Key terms: backstripping, foreland basins, inversion tectonics

Wed 04/09/03

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.

Mon 04/14/03

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.

Wed 04/16/03 

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.

Mon 04/21/03

Paleo-oceanography  and Paleoclimatology 
  • 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

Wed 04/23/03 

   
Mon 04/28/03  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. 

 

 

Labs

Thur 01/09/03 Stereonet Lab

Rickover 3

  1. Understand the concepts for dip and strike
  2. Plot a plane on a stereo net
  3. Determine the dip and strike of a plane from its projection.
  4. Plot a line on a stereo net.
  5. Determine the orientation of a line from its projection.
  6. Understand how we can plot a plane as a point on the projection (the pole).

References:

Thur 01/16/03  Quiz and Stereonet 2

Rickover 3

  1. Interpret earthquake focal mechanisms
Thur 01/23/03  Earthquakes and Volcanoes  

E10

  1. Understand where shield volcanoes and stratovolcanoes occur.
  2. Describe why earthquake databases have few records of very large or very small quakes.
  3. Discuss why both Ms and Mb scales exist for earthquakes.
Thur 01/30/03  DSDP Lecture

Stratigraphic correlations

E10

  1.  Differentiate lithostratigraphy and chronostratigraphy
  2. Understand what unconformities are
Thur 02/06/03  Sea floor features
  1.  Interpret bathymetric patterns at seismic and aseismic ridges.
  2. Use the pattern of sea floor crustal ages to infer the plate tectonic history of a region.
Thur 02/13/03   Plate rotations and magnetic anomalies  
Thur 02/20/03  Paper 2  
Thur 02/27/03 
Plate motions and triple junction stability 

(read GT 95-102 before lab)

 
Thur 03/06/03  Rainy Day Exercise  
Thur 03/20/03  YP Lab YP Lab--side scan sonar & subbottom profiler
Thur 03/27/03  YP Lab YP Lab--Sediment sampling
Thur 04/03/03  HOL  
Thur 04/10/03    Sediment analysis and distribution study
Thur 04/17/03    Sediment analysis and distribution study

Discuss the use of the Shepard ternary diagram for sediment size classification.

Thur 04/24/03 D10 Seismic reflection profiling

 

Rocks of the Day

Date Rock Learning Points
8 Jan Chert pebble conglomerate Recycling in geology
13 Jan Sandstone with trilobite trace fossil Types of fossils, not just body
15 Jan Quartz crystal Definitions of a rock and mineral
22 Jan Fault gouge Brittle surface deformation
27 Jan Granite Rock made of multiple minerals

Slow cooling, intrusive texture

29 Jan Maclurites fossil ("Big mac")

Cross bedded sandstone

  • Fossils come from a particular time and stratigraphic level
  • Cross-bedding from dunes and ripples
  • Unconformities mark absence of record for a time interval
5 Feb Mylonite Deep ductile deformation
10 Feb Coral pebble Rock tells us about climate where it formed
24 Feb Belemnite & Ammonite Free swimming fossils with hard shells make the best index fossils.
  Obsidian  
  Oolitic limestone  
  Pumice  
  Olivine basalt  
  Garnet schist