Which one of the following facts was not considered by those while discussing the concept of seafloor spreading?

The correct answer is Option 3.

Key Points

• In the seafloor spreading process, there is a gradual addition of new oceanic crust in the ocean floor through volcanic activity while moving the older rocks away from the mid-oceanic ridge.
• It is the result of mantle convection.
• It occurs at divergent plate boundaries.
• Seafloor spreading theory was proposed by an American geophysicist, Harry H. Hess.
• Facts considered as evidence in the proposition of seafloor spreading theory are the following:
  •  Magnetic stripes on the rocks,
  • Radiometric age dating of rocks and fossil ages,
  • Conventional current theory,
  • Seafloor mapping,
  • Volcanic activity along the mid-oceanic ridges.
• There was no discussion over the distribution of fossils in rocks found on different continents. Hence, option 3 is incorrect.