BRAIN TERRAIN FORMATION ON EARTH AND MARS

Brain terrain is a conspicuous landform that can be found across the mid-latitudes of Mars. It is characterized by an anastomosing complex of ridges and troughs arranged in a “brain-like” pattern. There have been only a handful of studies on brain terrain and its relationship with ice is debated. We recently characterized a unique landform on Earth, referred to Vermicular Ridge Features (VRFs) on Devon Island and Axel Heiberg Island in the Canadian High Arctic, Nunavut, that has strikingly similar morphological characteristics and morphometrics and scale to Martian brain. VRFs exhibit a circular, elongate, sinuous and/or anastomosing ridge and trough morphology in planform much like brain terrain. We interpret VRFs to be remnants of ice-cored hummocky moraines or other ice-marginal landforms that formed from the ablation and disintegration of stranded buried glacial ice. Based on the observations of VRF formation on Earth, we suggest that brain terrain on Mars forms from the disintegration of remnant buried massive glacial ice. This would suggest buried ice is, or was, present at one point in time where brain terrain exists on Mars. We test our hypothesis for brain terrain formation in Arcadia Planitia, Mars where evidence for buried ice has been detected and where we have mapped the distribution of brain terrain and other glacial and periglacial-related landforms. We identify a spatial and latitudinal relationship with brain terrain and provide implications for extant ice and past climate at Arcadia Planitia.