Heating of the Lithosphere during Meteorite Cratering

The formation of thermal anomalies around the impact sites of large cosmic bodies on the Earth is studied. The parameters of thermal anomalies are compared for the impacts of bodies of various scales—from one to several hundred kilometers in diameter. The cooling time of the rocks under impact craters of various scales is estimated. The estimates obtained are used to model the input of heat by the impacts of small (less than 500 km in diameter) planetesimals late in the accretion of the Earth. The boundary conditions for calculating the thermal evolution of the early Earth are refined by simultaneously analyzing the sizes of impact thermal anomalies and the model size distributions of projectiles (the mass spectrum of planetesimals).