Earth's mantle, not core, may have generated planet's magnetic field: Study

A new study has indicated that Earth's mantle, and not its liquid core, may have generated the planet's magnetic field. It showed how during the first half of Earth's 4.5-billion-year history, the "once-liquid" portion of lower mantle may have exceeded thresholds needed to create the field. Researches said the liquid silicate in Earth's mantle was more electrically conductive than believed.