Abstract
We report on evidence for fluid circulation in the upper crust of Mars, which could create environments favorable for life and its development. We investigate the nature of the thumbprint terrains covering part of Arcadia Planitia in the Martian northern hemisphere. Our analytic procedure allowed us to (i) hypothesise a potential relationship between these thumbprint terrains and an inferred underground fracture network that extends to where the clathrate-rich cryosphere contacts with the underlying hydrosphere; (ii) support the hypothesis that these thumbprint terrains are made of fine grained loosely packed materials erupted from deep beneath the subsurface mobilized by water; and (iii) date the thumbprint terrains of Arcadia Planitia to ~370 Ma. We conclude that the study area is an area worthy of astrobiological investigation, bringing water and fine grained sediment from depth to the surface for investigation.
Highlights
Our study area is in the northern lowlands, or “Vastitas Borealis”, and is located at mid-high latitudes, centered at 47°N 184°E, close to the central portion of Arcadia Planitia at around 4 km below the mean Martian elevation (Fig. 1)
In the Arcadia region we found low elevation mounds that are distinctly higher albedo compared to their surroundings and are characterized by perimeter moats and swellings, a rougher surface than their surroundings and a central pit surrounded by concentric troughs (Fig. 2a,c,d). We define these objects as Low Elevation and High Albedo Features (LEHAF) (Fig. 1a,b)
The large majority of the LEHAF are organized in tight arcuate chains (Figs 1 and 2d), where each individual feature frequently overlaps with adjacent one(s) to form ridges
Summary
Our study area is in the northern lowlands, or “Vastitas Borealis”, and is located at mid-high latitudes, centered at 47°N 184°E, close to the central portion of Arcadia Planitia at around 4 km below the mean Martian elevation (Fig. 1). The geological units underlying the study area are called the Vastitas Borealis marginal and interior units, and are interpreted to be the product of pervasive alteration during the Early Amazonian of sediments emplaced during outflow events in the Late Hesperian These outflow events are thought to be sourced from both the lowlands and highlands, and their deposits are sporadically covered by ejecta blankets from Amazonian craters[3]. Thumbprint terrains (TPT) are characterised by sets of curvilinear features made up of continuous and discontinuous alignments of pitted domes They are recognisable in several locations on the Northern hemisphere[3,8] with Arcadia Planitia amongst the main sites[2,4,9,10]. We combine geomorphological information, absolute model ages and the spatial distribution analysis of the TPT alignments and produce a consistent interpretation of the these features
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
