Evaluating the evolution of process specific degradation signatures aroundimpact craters

The pristine morphologies created during an impact event comprise a templat e for constraining how various environmental parameters influence the mecha nics of crater formation. Identification of pristine morphologies used in d efining and/or evaluating models of crater formation can be complicated or precluded however, by the effects of post-formation degradation. Field and/ or remote examination of simple, unglaciated impact craters on the Earth (e .g., Meteor Crater, Arizona, and Roter Kamm crater, Namibia) can yield resu lts that help to define characteristic degradation signatures for use in pl acing first-order constraints on the number and intensity of processes that have been active. In turn, the presence of a suite of these degradation si gnatures can be used to define the amount and style of crater degradation t hat has taken place, thereby providing a tool for possible distinction betw een pristine versus secondary, post-formation characteristics. (C) 1999 Els evier Science Ltd. All rights reserved.