Re: Pangea

[Scott <HORTON@BCRSSU.AGR.CA>]

>1) The concept of making "puzzle pieces" out of today's continents...

  The beauty of the continental drift theory is that it explains so many things
at once: the fitting together of continental coastlines and the continuation of
geological rock type formations across continents, earthquakes, volcanoes, rift 
valleys, mountain chains, the distribution of flora and fauna across the world,
etc.

>2) The "continental drift" as it applies to the theory of Pangaea...

  Plate movements are measurable today (a few cm per yr) through the use of
satellites.

>3) What is the theory for the creation of Pangaea?  What would...

  Pangea formed only a few hundred million years ago. The earth is 4550 million
years old. There is very little discussion about what the continental masses
looked like before Pangea. Probably because it's so difficult to work out
without any fossil evidence to trace geological formations before the Cambrian
Era (PreCambrian rocks tend to be granitic, which are much less informative than
sedimentary or volcanic strata).

>4) About the breakup, this has been blamed/credited for dividing...

  The breakup of Pangea undoubtedly affected ocean currents and weather
patterns. Areas that were once deserts could have become lush and green (and
vice-versa). Of course, this affects the evolution of dinosaurs.
  The movements of continents up and down in latitude will make a measurable
but insignificant change (a few seconds per day, if I remember right) to the
speed of rotation of the earth. I don't think the dinosaurs would have noticed,
they hadn't invented clocks yet ;-)

>5) On more earth-formation issue: I recall reading that the...

  As others have stated, you have to look at the borders of the continental
shelf when fitting continents together, not the current sea-level coastlines.

Scott Horton
Geophysicist/Computer Programmer