Dr. Nelson's Plate Tectonics Paradigm Unit...

...and Geoff Hagopian's Solutions
[page 1, page 2, page 3, page 4, page 5, page 6, page 7, page 8]
Spinning globe

Researching Part 4: Examine the graphic of sea floor topography from gravity readings*. Are all types of plate boundaries found in both the Atlantic and the Pacific Oceans?

Teacher Directed Questions: Students should include in their portfolio answers to the essay questions from above. What plate boundaries did you see, use this as a class discussion to close the lesson.

Dale S. Sawyer has a nice collection of info on this topic at http://www.ngdc.noaa.gov/mgg/announcements/text_predict.HTML
http://zephyr.rice.edu/plateboundary/
At this site: http://www.seismo.unr.edu/ftp/pub/louie/class/100/plate-tectonics.html
we find a nice description and illustration:

"...the Earth releases its internal heat by convecting, or boiling much like a pot of pudding on the stove. Hot
asthenospheric mantle rises to the surface and spreads laterally, transporting oceans and continents as on a slow conveyor belt. The speed of this motion is a few centimeters per year, about as fast as your fingernails grow. The new lithosphere, created at the ocean spreading centers, cools as it ages and eventually becomes dense enough to sink back into the mantle. The subducted crust releases water to form volcanic island chains above, and after a few hundred million years will be heated and recycled back to the spreading centers. "

Elsewhere we read that "There are three main plate tectonic environments: extensional, transform, and compressional. Plate boundaries in different localities are subject to different inter-plate stresses, producing these three types of earthquakes. Each type has its own special hazards. "

Oceanic spreading ridges such as those in the mid-Atlantic rift and the East Africa rift.
Subduction zones caused by converging continental plates, which often lead to deep trenches such as between the Nazca plate and the South American plate; the Aleutian trench in Alaska; the arc-trench systems in much of the western Pacific. The Continental lithosphere is not as dense as the oceanic lithosphere and so is not as prone to subduction, as witnessed here the Eurasian and Indian continents converge to create a very thick spot of the crust we call the Himalayas and Tibetan Plateau.
Transform Plate boundaries were two plates slide past eachother. The best example is perhaps the San Andreas Fault which passes a few miles from my home in the Mohave Desert. Many transform faults horizontally offset the divergent plate boundaries to produce the step like plate margins clearly shown on the maps.

So, to propose an answer to the question, no. There aren't oceanic spreading ridges in the Pacific and there aren't subduction zones in the Atlantic, at least so far as I can tell.

Researching Part 5: Examine the graphic of sea floor topography from gravity readings. Of the continents moving away from each other, which show the best fit between their margins (true geological margins, not just geographic margins), and which show the poorest fit.

Teacher Directed Questions: Students should include in their portfolio answers to the essay questions from above. In portfolio give reasons for the best (or poorest) fit.

Running the Quicktime movie ( http://www.ucmp.berkeley.edu/geology/tecall1_4.mov) over the last 200 years, it seems evident that North and South America fits pretty neatly with Europe and Africa, but the Indo-Australian, African and Eurasian plates show a pretty poor fit. There has been more fragmentation in this latter group and, for whatever reason, it seems the Indo-Australian plate has been moving north pretty fast and jammed pretty snug against the Eurasian plate.