| Thermal and Geochemical Effects of Impacts on Early Earth |
| Oleg Abramov |
| Planetary Science Institute, Tucson, AZ, USA |
| We use a three-dimensional thermal model to predict the age evolution of the Earth's crust from impacts in the time interval 4.5 to 3.5 Ga. Bombardment population parameters including delivered mass and impact flux decay are taken from dynamical studies as well as geochemical and geophysical constraints. We compare our bombardment simulation results to the age spectra published for the Hadean (pre-3.85 Ga) terrestrial zircon record. Results suggest that late accretion bombardment is unlikely to be the dominant process in modulating ages of Hadean zircons except perhaps very early in the planet's history. |