Signs of the «semiarid» pediplanation on Mars

Abstract

The ancient Martian craters evolution is shown to proceed about 3.5*10⁹ to 3.8*10⁹ yrs ago due to the pediplanation process (parallel slope retreat) according to the «semiarid» scheme, which is mostly under the action of sheet wash. A global planation surface of the pediplain type is shown to be formed at the time. The global scale of the «semiarid» pediplanation process on Mars during the period about 3.5*10⁹ to 3.8*10⁹ yrs ago suggests much denser atmosphere and higher temperature at the time than at present.