See more from this Division: Topical Sessions
See more from this Session: Planetary Pummeling: Cataclysmic Bombardment of the Solar System as Catastrophe, Catalyst, Cauldron, and Crucible
Abstract:
For craters formed in crystalline rocks the depth of excavation in complex craters can be derived from the maximum level of shock metamorphism in central peaks, assuming a specific rate of attenuation of the initial shock compression. The exponent of attenuation is generally taken as approximately -2 and does not vary significantly with crater size as long as the medium remain unchanged. However, the refraction wave that unloads and fragments the compressed target attenuates at a rate of -3 in small craters and even -4 or more in large terrestrial craters as tensile fracturing is inhibited by increased confining pressure. Thus large craters excavate less deeply than small craters relative to the shock imprint, the rocks of the central uplift are more strongly shocked and the proportion of fragmented material to impact melt decreases with size. Hence, by influencing the depth of fragmentation, gravity modulates the size of the window impacts open to planetary interiors.
See more from this Division: Topical Sessions
See more from this Session: Planetary Pummeling: Cataclysmic Bombardment of the Solar System as Catastrophe, Catalyst, Cauldron, and Crucible