The Martian Grid System, Continental Blocks and Continental Drift

Abstract

Summary Mars possesses two grid systems—a diagonal grid made up of lineaments trending approximately NW-SE and NE-SW, and a meridian-latitude grid composed of lineaments trending approximately N-S and E-W. The distribution of angles between the two families of lineament planes in the diagonal grid implies the existence of a 4-cell asymmetric convection pattern within the Martian mantle. The convection pattern readily explains the distribution of the major dark features, considered to be elevated continental blocks, by a continental drift hypothesis. The equatorial maria are elevated regions composed of E-W overthrust structures, while Mare Acidalium, the only major dark feature in the northern hemisphere, is a ridge-and-trough system comparable to a terrestrial oceanic rise. The Martian maria bear structural resemblances to the lunar highlands and the Martian deserts are similar to the lunar maria. Mars has undergone extensive tectonic development over a geological time-scale.