Depression Systems in Western Planum Boreum, Mars: Distributions, Orientations

Introduction: Planum Boreum, in the north polar region of Mars, forms a domical plateau largely dissected by depression systems of various dimensions (Fig.1). The largest and most deeply incised of these is Chasma Boreale, a unique canyon that divides Planum Boreum into a main lobe and a smaller lobe east of the chasma known as Gemina Lingula. Other widespread depression systems include undulations (linear surface depressions in the upper layered deposits) and troughs (linear depressions that extend into the lower layered deposits). We have mapped the distribution of troughs and undulations in western Planum Boreum (~180 to 360°E.) and investigated their stratigraphic relationships relative to one another, as well as relative to Chasma Boreale.