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When thinking about the formation of the current continents from a super-continent, it's clear that this is a gradual process, but there must be certain areas on earth which were once joined and were the "last" to break apart from Pangea.

Do we know when and where these rifting / break-up events took place?

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    $\begingroup$ Pangaea was not the only supercontinent by the way, it also formed by amalgamation of several continents (that broke from another supercontinent, Rodinia). The continents today will also likely form a supercontinent in a few million years. This is called the Wilson Cycle. That said, rifting is occurring as we speak. The Red Sea between east Africa and west Asia is such a rift and it will probably become a full sized ocean in the far future. $\endgroup$ – Gimelist Jul 19 '15 at 11:24
  • $\begingroup$ Yes Red Sea Rift might be the best answer to the question. It started already in late Cretaceous (or early Paleogene), but is still ongoing. $\endgroup$ – Tactopoda Jul 19 '15 at 11:32
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Rifting is an ongoing process. At the moment, e.g. East Africa is rifting apart from the Nubian plate, we also see rifting of continental plates elsewhere, eg Rio Grande. New continents are being formed, but it doesn't happen on a human time scale. Modellers of future geography have a difficult task to decide what rifts that will stop and what rift that eventually will result in a new continent.

See yellow marked faults and rifts: enter image description here

Madagascar is sometimes refereed to as the eight continent, not only of biogeographic reasons. It was rifting away from Africa and later India during mesozoic time, starting 160 Ma.

The last rifting that resulted in the present continents I can think about (probably the community can come up with a later event!), would be the North Atlantic breakup, that is still ongoing, but the last part of separation of present continents was the opening of the Fram Strait 16-10 Ma. This separated Greenland from the European plate and had a large impact on the Arctic Ocean conditions.

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Some may without basis, dislike this answer, but I believe you will find that the overall pattern of continents coming together, and drifting apart is in direct response to the orbit of the sun around the milky way. The periodicity matches and there are other tell-tales that add strength to the belief. I havent heard or found a better explanation for the period of this occurrence. And one side of the world, seems almost entirely void of continents, adding weight to something one-sided "attracting" the continents.

Gravity is a wave pattern. There are those that are looking for it's shape. But one thing for sure, it has an "interference pattern". Please follow this link, and then set the smoothing radius to 25km, and map type "monthly anomalies, then browse, from 2002 through 2014. If you have experience with wave tables and interference patterns, you will see that there is an interference pattern, which tells you gravity is both coming and going. Then especially make note of the pattern greenland has in an 11 year cycle... sample 2002, 2007, 2013. It is obviously "bouncing" as it's pattern and the incoming pattern are running "lateral" to one another. This happens due to the reversal of the magnetic field of the sun. The link to the GRACE mission results are here:

NASA - GRACE Mission Data Analysis Portal Hosted at Colorado U.

AS a proposed "shape of gravity" I would have you consider this picture. It is gravity in a neutral "temperment".:

Gravity without imbalances

Sorry i didn't include GRACE's results link the first time round.

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    $\begingroup$ Astronomical influence of tectonic have been discussed, you might find this article interesting: 151.100.51.154/dst1/sciterra/sezioni/doglioni/Publ_download/… For a general understanding of gravity force and how it's affected of distance there are many introductions online. This might be a helpful for a start: physicsclassroom.com/class/circles/Lesson-3/… $\endgroup$ – Tactopoda Jul 24 '15 at 6:36
  • $\begingroup$ Are you assuming the the continents are more massive than the oceans? That premise is fundamental to your suggestion, except that it's wrong. There is not any more mass in the continents that can be attracted compared to oceans. $\endgroup$ – Gimelist Jul 27 '15 at 8:07

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