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