Pits are circular to elliptical,steep-sided,flat-bottomed depressions interpreted to form from collapse into a cavity.They occur on Earth,Venus and Mars and range in diameter from;00 m to several kilometres(e.g.
文摘Pits are circular to elliptical,steep-sided,flat-bottomed depressions interpreted to form from collapse into a cavity.They occur on Earth,Venus and Mars and range in diameter from;00 m to several kilometres(e.g.