Talk:Supercontinent
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[edit] Mu
If it actually existed shouldn't Mu be included on this list,or at least mentioned. —Preceding unsigned comment added by 64.12.116.137 (talk • contribs)
- Mu was unfortunately obsoleted by plate tectonics, and didn't actually exist. Also, it was hypothesized as a regular continent, not a supercontinent, since supercontinents as described here require plate tectonics to form. Darekun 01:12, 18 October 2007 (UTC)
[edit] Inconsistency
The first paragraph says "The assembly of cratons and accreted terranes that form Eurasia[1] qualifies as a supercontinent today", and further down we read "Some historians call the combined land mass of Africa and Eurasia the supercontinent Africa-Eurasia, but it is not a geological supercontinent". Is Eurasia counted as a supercontinent by geologists, or is it not? It can't be both, y'know. :-) Dr Zak 01:43, 26 June 2006 (UTC)
The greatest inconsistency in the whole list is;
- What is a supercontinent? Apparently, looking at this list, any major orogenic or rifting event brackets a "supercontinent". This is basically model driven terminology, because the authors appear to suggest that plate ectonics cannot exist without forming or destroying a supercontinent. There is no consistent standard expressed as to what constitutes a supercontinent except "something kludged together".
The second greatest are;
- The Komaii formation. Its not a supercontinent, its a single lava event.
- The Yilgarn Craton. In fact, most of these are "cratons" not superconinents. Or protocratons. Of course, there's a reason for this; most >500Ma rocks are in cratons. Making the leap to say that these rocks, in most cases metamorphosed, are produced on supercontinents is a different kettle of fish.
Rolinator 11:48, 15 October 2006 (UTC)
- Agreed, the Komatii Formation and Yilgarn Craton don't seem to belong on this list. Unless someone objects I'll remove them in a few days.
- Cephal-odd 22:45, 26 December 2006 (UTC)
[edit] Ur
in the opening paragraph the article states you have to fit specific conditions to be called a supercontinent, but then under Ur it says that one could argue it was a supercontinent (presuably because it was big for its time?) which is inconsistent. Perhaps it should be shuffled down to the notes section...
[edit] List of supercontinents
Do we need a separate List of supercontinents article when most of the same lists appear in this one? We should either merge the articles or remove the lists here to the other article. Cephal-odd 16:32, 25 November 2006 (UTC)
[edit] Computer Simulation of the History of Earth Formation
It would be nice to have a computer simulation of the history of supercontinents. I have seen a few maps and simulation, but they are incomplete. I would like to see one that shows the increase in size of our Earth over time through accretion of mass, and can be revolved to show the globe from all sizes at any time in history. Maybe a job for Google Earth?--Robert van der Hoff 04:39, 11 May 2007 (UTC)
[edit] List of Supercontinents and definition
As far as I am aware, the only supercontinents were Rodinia, Pannotia, Pangaea and to a lesser extent, Gondwana and Laurasia. Labelling Oceania a 'supercontinent' is wrong, it is just a standard continent.
A good explanation of supercontinents which I agree with is in the Sci-Tech Encyclopedia:
The six major continents today are Africa, Antarctica, Australia, Eurasia, North America, and South America. Prior to the formation of the Atlantic, Indian, and Southern ocean basins over the past 180 million years by the process known as sea-floor spreading, the continents were assembled in one supercontinent called Pangea (literally “all Earth”). Pangea came together by the collision, about 300 million years ago (Ma), of two smaller masses of continental rock, Laurasia and Gondwanaland. Laurasia comprised the combined continents of ancient North America (known as Laurentia), Europe, and Asia. Africa, Antarctica, Australia, India, and South America made up Gondwanaland (this name comes from a region in southern India). The term “supercontinent” is also applied to Laurasia and Gondwanaland; hence it is used in referring to a continental mass significantly bigger than any of today's continents. A supercontinent may therefore incorporate almost all of the Earth's continental rocks, as did Pangea, but that is not implied by the word.
Laurasia, Gondwanaland, and Pangea are the earliest supercontinental entities whose former existence can be proven. Evidence of older rifted continental margins, for example surrounding Laurentia and on the Pacific margins of South America, Antarctica, and Australia, point to the existence of older supercontinents. The hypothetical Rodinia (literally “the mother of all continents”) may have existed 800–1000 Ma, and Pannotia (meaning “the all-southern supercontinent”) fleetingly around 550 Ma. Both are believed to have included most of the Earth's continental material. There may have been still earlier supercontinents, because large-scale continents, at least the size of southern Africa or Western Australia, existed as early as 2500 Ma at the end of Archean times.
The amalgamation and fragmentation of supercontinents are the largest-scale manifestation of tectonic forces within the Earth. The cause of such events is highly controversial.
—Preceding unsigned comment added by Ear4rgjb (talk • contribs) 09:52, 21 January 2009
- Cut the list, redundant w/ List of supercontinents Vsmith (talk) 12:28, 21 January 2009 (UTC)
