Widespread mixing and burial of Earth’s Hadean crust by asteroid impacts

@article{Marchi2014WidespreadMA,
  title={Widespread mixing and burial of Earth’s Hadean crust by asteroid impacts},
  author={Simone Marchi and William F. Bottke and Linda T. Elkins‐Tanton and M. Bierhaus and K. Wuennemann and Alessandro Morbidelli and David A. Kring},
  journal={Nature},
  year={2014},
  volume={511},
  pages={578-582}
}
The history of the Hadean Earth (∼4.0–4.5 billion years ago) is poorly understood because few known rocks are older than ∼3.8 billion years old. The main constraints from this era come from ancient submillimetre zircon grains. Some of these zircons date back to ∼4.4 billion years ago when the Moon, and presumably the Earth, was being pummelled by an enormous flux of extraterrestrial bodies. The magnitude and exact timing of these early terrestrial impacts, and their effects on crustal growth… 
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