Hadean
An explanation for the general lack of Hadean rocks (older than 3800 mya) is the large amount of rocky and icy debris present in the early Solar System. After the eight planets formed, large numbers of leftover protoplanets, asteroids, and comets pursued eccentric orbits throughout our system, bombarding the early Earth and the other planets and moons until approximately 3800 mya. This activity may have prevented any large crustal fragments from forming by literally shattering the early protocontinents. A barrage of particularly large impacts known as the Late Heavy Bombardment represents the climax of this violent era.