A study of Samoan volcano hotspots has found evidence of the planet's early formation still trapped inside the Earth.
Volcanic island chains such as Samoa can contain ancient primordial signatures from the early solar system that have survived for billions of years. To make their determination, the researchers utilized high-precision lead and helium isotope measurements to unravel the chemical composition and geometry of the deep mantle plume feeding Samoa's volcanoes.
In most cases, volcanoes are located at the point where two tectonic plates meet, and are created when those plates collide or diverge. Hotspot volcanoes, however, are not located at plate boundaries but rather represent the anomalous melting in the interior of the plates.