Where there continents before Pangea?

Discussion in 'Earth Science' started by John J. Bannan, Aug 6, 2007.

  1. John J. Bannan Registered Senior Member

    Messages:
    1,471
    Where the continents divided before Pangea?
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. spidergoat Valued Senior Member

    Messages:
    51,740
    Do you mean "were" the continents divided before Pangea?

    Possibly, but that was so long ago it's hard to say.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. GeoffP Caput gerat lupinum Valued Senior Member

    Messages:
    22,087
    Atlantis, apparently.

    That is, before the comet hit it and smushed it and all the dinosaurs.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. S.A.M. uniquely dreadful Valued Senior Member

    Messages:
    72,822
    We don't know, present knowledge is based on continental drift after the divide.

    I've always found this rendition very interesting.

    http://pubs.usgs.gov/gip/dynamic/historical.html

    Please Register or Log in to view the hidden image!

    Please Register or Log in to view the hidden image!

     
  8. John J. Bannan Registered Senior Member

    Messages:
    1,471
    Well, isn't the ocean older than Pangea? If so, there probably were continents before Pangea. Why would it be so hard for geologists to study this?
     
  9. temur man of no words Registered Senior Member

    Messages:
    1,330
    Well, I think there are many simulations, but the further you go into the past, the less the accuracy of the simulation would be.
     
  10. P. BOOM! Registered Senior Member

    Messages:
    122
  11. nietzschefan Thread Killer Valued Senior Member

    Messages:
    7,721
    That looks pretty good. Every thing west of the rocky mountains(the mountains themselves) is a collection of stuff roughed up from north america's movement west. Same thing in south america - Peru.
     
  12. mikasa11 Registered Senior Member

    Messages:
    258
    I remembering reading somewhere that the Appalachian Mountains were formed from North America collding into Africa before pangaea.
     
  13. mikasa11 Registered Senior Member

    Messages:
    258
    Are you talking about the ocean floor or the water that makes up the ocean?

    The ocean floor is constantly being subducted under continental plates, thus meaning the oceanic plates are relatively young (in geologic terms) compared to the continental plates. The oldest oceanic plate is in the Pacific Ocean and about 200 million years old.
     
  14. John J. Bannan Registered Senior Member

    Messages:
    1,471
    I am referring to the water in the form of an ocean.
     
  15. P. BOOM! Registered Senior Member

    Messages:
    122

    Uh, didn't anyone see my post?? Kind of hard to miss. The old oceans are even named! BTW, 458 Ma means 458 million years ago, before Pangea was formed. Go to www.scotese.com
    to see more reconstructions.
     
  16. John J. Bannan Registered Senior Member

    Messages:
    1,471
    Yes, I saw it. Very good site, but a little cheesy. Don't have much confidence in the site.
     
  17. guthrie paradox generator Registered Senior Member

    Messages:
    4,089
    John, that site braodly agrees with my geology textbook. Interestingly enough, the reference for the picture in my textbook is:
    R K Bambach , C R Scotese and AM Zeigler, "BEfore Pangea: the Geography of the Paleozoic world", American scientist, Vol 68, January 1980.
    The picture is from an early article by the very person whose website you do not have much confidence in.
    Professor Scotese seems to have a long publication record in the field of geological reconstructions.
     
  18. Facial Valued Senior Member

    Messages:
    2,217
    It appears highly likely that there were. Rodinia was a supercontinent hypothesized to exist before Pangaea.
     
  19. Pandaemoni Valued Senior Member

    Messages:
    3,631

    It's not about his qualifications, it's that he can't afford a decent web developer. If his theories were right, they'd make more money, and he'd be able to afford better production values for his website. The market has spoken.
     
  20. matthyaouw Registered Senior Member

    Messages:
    162
    Seriously? Judge the site on its content rather than how nice and shiny the graphics are...
     
  21. EmptyForceOfChi Banned Banned

    Messages:
    10,848

    i always thought rodinia was a tight knit type of archipelago grouping, instead of a fused type continent.

    what about gondwana?


    peace.
     
  22. Pete It's not rocket surgery Moderator

    Messages:
    10,166
    Wikipedia lists crapload of pre-Pangea continents, but I haven't chased up enough references to judge the reliability of the list.

    The best that I did chase up is stuff by geologist John Rogers.

    Popular press:
    In the beginning, there was Ur

    Journal article:
    Rogers, John J.W., 1996, A history of continents in the past three billion years, Journal of Geology, Jan1996, Vol. 104 Issue 1, p91.
    Available by subscription through EBSCOhost.
    Abstract:
    The end-Paleozoic Pangea appears to have contained three continents that had grown in the Precambrian and remained intact until Mesozoic refting: Ur, formed at ~3 Ga and accreted to most of East Antarctica in the middle Proterozoic to form East Gondwana; Arctica, and approximately 2.5-2 Ga continents that contained Archean terranes of the Canadian and Siberian shields and Greenland; and Atlantica, formed at ~2 Ga of cratons of ~2 Ga age that now occur in West Africa and eastern South America. Arctica grew at ~1.5 Ga by accretion of most of East Antarctica plus Baltica to form the continent of Nena. Collision of Nena, Ur, and Atlantica, plus minor plates, formed the supercontinent of Rodina at ~1 Ga. Rifting of Rodinia between 1 and 0.5 Ga formed three continents: East Gondwana; Atlantica (which became the nucleus for West Gondwana); and Laurasia (which contained North America, Greenland, Baltica, and Siberia). Gondwana formed at ~0.5 Ga by amalgamation of its eastern and western parts. Various plates accreted to Laurasia during the Plaeozoic, and collision of Gondwana with Laurasia created Pangea at ~0.3 Ga.
     
  23. guthrie paradox generator Registered Senior Member

    Messages:
    4,089
    He's being sarcastic.
     

Share This Page