Naked Science Forum
Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: neilep on 04/09/2007 17:19:16
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Dear Pangea pageants,
Pangea was like...well big !!
even bigger than my window-box and that is very big !!
here it is (Pangaea that is)
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Was Pangea the first landmass that existed on the Earth ?...or did it start off with little bits that came together ?
why did it separate into the continents we know and luff today ?....will it come back together ?..and then will it separate again ?
I just don't know.....I need someone who was around the first time to explain it to me...erhhmm..JB ? [;D]
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http://en.wikipedia.org/wiki/Supercontinent#History
Most commonly, paleogeographers employ the term supercontinent to refer to a single landmass consisting of all the modern continents. The earliest known supercontinent was Vaalbara. It formed from proto-continents and was a supercontinent by 3.1 billion years ago (3.1 Ga). Vaalbara broke up ~2.8 Ga. The supercontinent Kenorland was formed ~2.7 Ga and then broke sometime after 2.5 Ga into the proto-continent cratons called Laurentia, Baltica, Australia, and Kalahari. The supercontinent Columbia formed and broke up during a period of 1.8 to 1.5 billion years (1.8-1.5 Ga) ago.
The supercontinent Rodinia broke up roughly 750 million years ago. One of the fragments included large parts of the continents now located in the southern hemisphere. Plate tectonics brought the fragments of Rodinia back together in a different configuration during the late Paleozoic era, forming the best-known supercontinent, Pangaea. Pangaea subsequently broke up into the northern and southern supercontinents, Laurasia and Gondwana.
Modern studies have suggested that supercontinents form in cycles, coming together and breaking apart again through plate tectonics, very roughly about every 250 million years.
So, while Pangaea was the last complete supercontinent (lesser superconentinents existed subsequently), but it was neither the first, nor will it be the last.
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Thanks GEORGE.....so..for the time being my post code is safe yes ?...good !!
(US Translation service: ' Post code ' = ' Zip Code '...sheesh !!)
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What?????
Post code = zip code??????
What will they think of next?
(good thing you're there Neil- to keep us upstarts from getting too uppity)
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What?????
Post code = zip code??????
What will they think of next?
(good thing you're there Neil- to keep us upstarts from getting too uppity)
I'm just glad to be of service !! [;D]
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Dear Pangea pageants,
Was Pangea the first landmass that existed on the Earth ?...or did it start off with little bits that came together ?
why did it separate into the continents we know and luff today ?....will it come back together ?..and then will it separate again ?
I just don't know.....I need someone who was around the first time to explain it to me...erhhmm..JB ? [;D]
While multiple supercontinents have formed and broken up over the past few billion years (seems like just yesterday [::)])
I think your comment about "starting off with little bits that came together" is probably what happened. In the good old Hadean and Archean days, as the crust began to cool- leading to subduction and fractionation of rocks, the seeds of the first continents were probably like island arcs (Japan) today. I suspect these less dense 'microcontinents' began moving around, bumping into one another and forming larger and larger continental landmasses.
If you want to see the future of plate tectonics, check out the Paleomap Project http://www.scotese.com/earth.htm (http://www.scotese.com/earth.htm) - especially the animations. This site also shows past tectonic changes.
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Dear Pangea pageants,
Was Pangea the first landmass that existed on the Earth ?...or did it start off with little bits that came together ?
why did it separate into the continents we know and luff today ?....will it come back together ?..and then will it separate again ?
I just don't know.....I need someone who was around the first time to explain it to me...erhhmm..JB ? [;D]
While multiple supercontinents have formed and broken up over the past few billion years (seems like just yesterday [::)])
I think your comment about "starting off with little bits that came together" is probably what happened. In the good old Hadean and Archean days, as the crust began to cool- leading to subduction and fractionation of rocks, the seeds of the first continents were probably like island arcs (Japan) today. I suspect these less dense 'microcontinents' began moving around, bumping into one another and forming larger and larger continental landmasses.
If you want to see the future of plate tectonics, check out the Paleomap Project http://www.scotese.com/earth.htm (http://www.scotese.com/earth.htm) - especially the animations. This site also shows past tectonic changes.
Mr Bass...THANK YOU VERY MUCH Indeed !
That site is fantastic and the animations very clever. Whilst I am awaiting the Early Permian World VR animation to load I wanted to get back here and say Ta !!
Do you know by any chance how long the current ratio of land to water has existed ?...this could lead onto a load of other questions asking about how long has the current quantity of water been about ?...does more land equate to deeper oceans ?...etc etc....
These questions are of course open to everybody so that Mr Bass can take a rest !! [;)]
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While multiple supercontinents have formed and broken up over the past few billion years (seems like just yesterday [::)])
I think your comment about "starting off with little bits that came together" is probably what happened. In the good old Hadean and Archean days, as the crust began to cool- leading to subduction and fractionation of rocks, the seeds of the first continents were probably like island arcs (Japan) today. I suspect these less dense 'microcontinents' began moving around, bumping into one another and forming larger and larger continental landmasses.
Does it not depend on how much water existed on the early Earth?