According to this concept, new sea floor rock (basalt) is added to the edges of the North American, South American, Eurasian, and African plates. The result of the addition of new sea floor rock at the Mid-Atlantic Ridge (MAR) is that the Atlantic Ocean between these sets of continents is widening.North and South America move farther away from Eurasia and Africa each year.ccording to this concept, new sea floor rock (basalt) is added to the edges of the North American, South American, Eurasian, and African plates. The result of the addition of new sea floor rock at the Mid-Atlantic Ridge (MAR) is that the Atlantic Ocean between these sets of continents is widening.