The effects of differential scaling of impact melt and crater dimensions on lunar and terrestrial craters: Some brief examples
Published:January 01, 1992
Mark J. Cintala, Richard A. F. Grieve, 1992. "The effects of differential scaling of impact melt and crater dimensions on lunar and terrestrial craters: Some brief examples", Large Meteorite Impacts and Planetary Evolution, B. O. Dressier, R.A.F. Grieve, V. L. Sharpton
Download citation file:
Three of the principal variables in scaling impact-crater dimensions are the impact velocity, the projectile size, and the gravitational acceleration of the target body. The amount of impact melt generated by an impact, however, is independent of gravity, but will grow in direct proportion to the projectile dimensions and as an increasing function of the impact velocity. Thus, if the impact velocity and gravitational acceleration were held constant and projectiles of increasing size were considered, the amount of melt generated relative to the dimensions of the final crater would grow at a steady rate. Using the Earth and the Moon for comparison, this paper examines the effects of differential scaling on the depth of origin of central-peak material, on the amount of stratigraphic uplift associated with the formation of those peaks, and on the clast contents of impact melts. When craters of similar size are compared, central peaks should be derived from greater depths on Earth because of relatively deeper melting. The amount of stratigraphic uplift, however, should be greater on the Moon. A lunar crater will be larger than its terrestrial counterpart formed by an identical projectile, but the terrestrial crater will be accompanied by substantially more impact melt. As a large fraction of the melt would have lined the transient cavity during the excavation stage of the impact event, a greater fraction of the lunar melt will have been in contact with clastic materials on the cavity wall. Thus, the clast contents of lunar impact melts should be higher than in those in terrestrial craters of similar size.