Tectonic Deformation and Volatile Loss in the Formation of Noctis Labyrinthus, Mars

Abstract

Introduction Noctis LabyrinthusNoctis Labyrinthus, Mars, is situated east of the Tharsis rise, at the western end of Valles Marineris (Figure 1a). Despite being located between the biggest volcanic complex and largest canyon system on the planet, the exact nature and formational history of Noctis Labyrinthus is not well understood. The region sits on a topographic high and could be considered a dissected dome or plateau (Andrews-Hanna, 2012a, 2012b, 2012c) (Figure 1b). The region abounds with normal faults (Bistacchi et al., 2004;Masson, 1977) and pit craters. Large troughs cross-cut both the normal faults and pit craters (Figure 1b). Additionally, hillslope modification within the troughs of Noctis Labyrinthus is evidenced by landslides and periglacial features (Hajna et al., 2017;Rodriguez et al., 2016) that together are indicative of mass-wasting processes that have helped shape the troughs.The broad structural characteristics of Noctis Labyrinthus have been recognized since the original mapping from Viking imagery by Masson (1977), who concluded that the region resembled the East African

Seismic Reflection Data Reveal the 3D Subsurface Structure of Pit Craters

“…However, there is no meaningful correlation ( R 2 = <0.1) for deflection height and pit long axis length (Figure 11). The deflection height measurements also fall an order of magnitude below the power‐law trend fit to the compiled published pit crater data; this trend is similar to pit craters in Noctis Labyrinthus (Mars), which display evidence for post‐formation modification of their initial geometries (Figure 11) (Kling et al., 2021). Based on these comparisons, we suggest that the walls of the inverted cone sections represent the original pit crater morphology; that is, cone height is equivalent to pit crater depth.…”

“…Similarly, those pit craters widespread in Noctis Labyrinthus (Mars) have dimensions up to an order of magnitude below the power-law trend described by published data (Figure 11) (Frumkin & Naor, 2019;Kling et al, 2021). These deviations from the main power-law trend have been attributed to post-emplacement modification by erosion and sedimentation, causing pit craters to become shallower and wider with time (Frumkin & Naor, 2019;Kling et al, 2021).…”

“…Yet some potentially dike-or fault-related pit craters show no correlation between pit crater depth and long axis length, such as those in the Golan volcanic province, southern Levant (R 2 = 0.05; Figure 11). Similarly, those pit craters widespread in Noctis Labyrinthus (Mars) have dimensions up to an order of magnitude below the power-law trend described by published data (Figure 11) (Frumkin & Naor, 2019;Kling et al, 2021). These deviations from the main power-law trend have been attributed to post-emplacement modification by erosion and sedimentation, causing pit craters to become shallower and wider with time (Frumkin & Naor, 2019;Kling et al, 2021).…”

“…From these values, we calculate the plan‐view aspect ratio of the pit crater planform shape. By using these parameters to define the plan‐view morphology of the studied pit craters, we can compare them to the surface expression of pits elsewhere (e.g., Kling et al., 2021; Whitten & Martin, 2019), and assess any relationship between their geometry and subsurface structures and/or stresses (e.g., Magee & Jackson, 2020b; Paulsen & Wilson, 2010).…”

“…Insets show a zoomed-in view of our data and the power-law best-fit trendlines for each plotted data set. The power-law best-fit trendline shown (black line) with standard errors was calculated from all literature data plotted, with the exception of data from Frumkin and Naor (2019) and Kling et al (2021) as these pit craters show evidence of post-formation modification. We define an arbitrary boundary between areas where pit crater geometries are likely original (areas above the line) and those where infilling and/or erosion may have modified apparent pit crater depths (areas below the line).…”