An Overview of Volcano Flank Terraces on Mars

Introduction: Flank terraces are topographically subtle, laterally extensive structures on the flanks of several large Martian volcanoes [1]. The origin of terraces has been ascribed to several mechanisms, including elastic self-loading [2], lithospheric flexure [3], gravitational spreading [4], magma chamber tumes-cence [5], and shallow slumping [6]. Here we summa-rise the results of our work to characterise flank terrace geometry, determine the causal mechanism of terrace formation, and establish the role of terraces within the volcanotectonic evolution of large volcanoes on Mars. Observations: Flank terraces have a convex-upward profile in cross section, consistent with thrust fault morphology. As convex-outward structures in plan view, they form an imbricate, " fish scale " pattern upon each terraced volcano (fig. 1). Using Mars Or-biter Laser Altimeter (MOLA) [7] and Shuttle Radar