My science/technology-related thoughts, sometimes controversial, sometimes can be based on limited knowledge base, logic can be non-perfect as well. I develop my vision in iterations. Don't take this blog as an attempt to convince anybody in anything.
Each post in this blog reflects my level of understanding of Tectonics of the Earth at the time the post was written; so, some posts may not necessarily be correct now.

12 July, 2011

Reshaping Pangaea.

   Last weeks I've been trying to approach "Basalt Flows" theme. I think, I need to step back and reshape some aspects of the big picture. The idea of this post is to rethink the separation of Pangaea into the continents and how the continents drifted to their current positions.

The documentss/tools used:

- NASA, Earth Observatory, "Alfred Wegener (1880-1930)" by Patrick Hughes, map on Wegener's fossil and geological evidence that the continents were previously connected ( http://earthobservatory.nasa.gov/Features/Wegener/wegener_4.php ) [accessed on Jul-12, 2011]

- "Some General Concepts underlying the Science of Geology", primary author Nicholas M. Short, Sr. , section 2, "The Rock Cycle" ( http://rst.gsfc.nasa.gov/Sect2/Sect2_1b.html ), image showing the positions of the continents from early Pangaean breakup to the Present. [accessed on Jul-12, 2011]

- your favourite map tool, set it to accommodate the whole World, the mode is "satellite".

Optimizing Pangaea initial layout.

   Let's have a look at the mentioned image showing the positions of the continents from early Pangaean breakup to the Present. While the Wegener's reason behind the layout is clear, we need to keep in mind that the Earth is spherical, and therefore the layout can be optimized to keep the color paths shorter and a bit more logically consistent - to minimize flora/fauna needs to overcome the high mountain systems. Just position initially on the mentioned image:
- Australia at the West of South America, the place that roughly corresponds to the current Atakama desert location, Chile.
- New Zealand - again, western border of South America, below Australia.
- India - place its cratons to western Australia.
- Antarctica - place it more North-East up on the Equator.
I am absolutely sure I am not the first who suggested the layout. I'd like to credit the first person who suggested the layout, as soon as I find the info.

Continents drift paths.

   In our approach North and South America motions remain the same to the traditional ones.
   Regarding India, Australia, New Zealand - let's have a look at Google map. Let's take a closer look at the shapes of eastern and western subduction zones. Do not the eastern and western shapes resemble each other? If the oceanic floor on the map between the shapes were cut off the map, would not the shapes fit each other? Had not the shapes been diverged out? Clearly, yes, judging by the East-West rifts on the floor.
   Wait, some would say, we can see how South America could cast off India, Australia, New Zealand, but how did it manage to cast off the "forward-running subduction zone"? Well, that's the theme for another posting.
   Now we see how the tremendous amount of the assorted stuff had been pushed towards the location now known as Tibet/Himalaya. The stuff eventually was locked by India's deep-rooted cratons, and the incoming and subducting plates had had no choice to escape the location when getting semi-molten and therefore, the choice other than to be pushing up the gigantic cluster of mountain systems.
   Antarctica and later, the divergent Indian ocean floor blocked the mentioned above stream of the assorted stuff from propagating westward to Africa.
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reposted from http://sukhotinsky.blogspot.com/

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edited Aug-17, 2011.

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