What geological feature, sharing Earth's orbit at the L4 and L5 points 60 degrees ahead and behind, is mentioned as a concept distinct from matter inside Earth?

Trojan bodies

When considering objects in Earth's 'domain' but external to its mass, the concept of Trojan bodies arises. These are asteroids, or hypothetical celestial bodies, that share a planet's orbit around the Sun, congregating gravitationally in stable regions known as Lagrange points. Specifically, L4 is the point trailing 60 degrees behind the planet, and L5 is the point leading 60 degrees ahead of the planet in their shared orbit. While Jupiter hosts numerous Trojans, Earth's corresponding L4 and L5 points are observed to be largely clear of large, stable bodies. This concept describes separate orbiting companions, differentiating them entirely from the scenario where planetary material is physically embedded deep within the Earth's interior, as is proposed for the Theia remnants.