The cretaceous-tertiary mass extinction was apparently caused by a meteorite that struck Yucatan Peninsule in Mexico
Seafloor mapping during WWI and the Cold War had revealed the details of the physical structure of the ocean ridge system, and discovery of magnetic stripes on the ocean floor was the crucial turning point in development of plate tectonic theory. when deep-sea line soundings (bathymetric surveys) were routinely made in the Atlantic and Caribbean.
