How has potassium-argon dating helped scientists study mid-ocean ridges?

Potassium-argon dating has been instrumental in studying mid-ocean ridges by providing a reliable method to determine the ages of volcanic rocks found on the ocean floor.1

Scientists use this technique to date the stripes of alternating normally and reversely magnetized volcanic rocks that parallel the axes of mid-oceanic ridges. Because basaltic magma extruded from these ridges captures the orientation of Earth’s magnetic field at the time of its formation, these magnetic lineations serve as a record of seafloor spreading. By applying potassium-argon dating to these rocks, researchers can calibrate the geomagnetic polarity succession to a specific time scale.12

This integration of isotopic ages with magnetostratigraphy allows scientists to reconstruct the history of seafloor spreading and develop a high-resolution, internally consistent geologic time scale.2