Impact cratering mechanics and structures
Abstract
Hypervelocity impact craters formed in the laboratory in low- and variable-strength materials have provided insight into the mechanics of the formation and the resultant structures of meteorite craters. Three stages in the development of a crater are recognized: (1) an initial shock wave compression of projectile and target, during which kinetic energy is transferred from impacting body to the ground; (2) an excavation stage, during which the crater is actually formed as the result of particle motions produced by the shock waves; and (3) a stage of post-cratering modification of the basic impact-basin by geologic processes. Crater structures produced in low strength target materials are remarkably similar to those found in certain large meteorite craters. Upwarped rims with inverted stratigraphy, near surface overthrusts, stratigraphically deep underthrusts, and polygonal rims have all been observed. These structures are consistent with, and are the natural consequence of, the particle motions and deformations associated with the mechanics of formation of an impact crater.
- Publication:
-
A Primer in Lunar Geology
- Pub Date:
- July 1974
- Bibcode:
- 1974plug.nasa..177G
- Keywords:
-
- Hypervelocity Impact;
- Lunar Craters;
- Lunar Topography;
- Meteoritic Damage;
- Experiment Design;
- Mechanical Shock;
- Meteorite Craters;
- Planetary Structure;
- Simulation;
- Test Facilities;
- Geophysics